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Note: This page contains sample records for the topic "advanced ceramic composites" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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1

Nondestructive evaluation of advanced ceramic composite materials  

SciTech Connect (OSTI)

Nondestructive evaluation techniques were developed to characterize performance degrading conditions in continuous fiber-reinforced silicon carbide/silicon carbide composites. Porosity, fiber-matrix interface bond strength, and physical damage were among the conditions studied. The material studied is formed by chemical vapor infiltration (CVI) of the matrix material into a preform of woven reinforcing fibers. Acoustic, ultrasonic, and vibration response techniques were studied. Porosity was investigated because of its inherent presence in the CVI process and of the resultant degradation of material strength. Correlations between porosity and ultrasonic attenuation and velocity were clearly demonstrated. The ability of ultrasonic transmission scanning techniques to map variations in porosity in a single sample was also demonstrated. The fiber-matrix interface bond was studied because of its importance in determining the fracture toughness of the material. Correlations between interface bonding and acoustic and ultrasonic properties were observed. These results are presented along with those obtained form acoustic and vibration response measurements on material samples subjected to mechanical impact damage. This is the final report on research sponsored by the US Department of Energy, Fossil Energy Advanced Research and Technology Development Materials Program. 10 refs., 24 figs., 2 tabs.

Lott, L.A.; Kunerth, D.C.; Walter, J.B.

1991-09-01T23:59:59.000Z

2

Advanced Measurements of Silicon Carbide Ceramic Matrix Composites  

SciTech Connect (OSTI)

Silicon carbide (SiC) is being considered as a fuel cladding material for accident tolerant fuel under the Light Water Reactor Sustainability (LWRS) Program sponsored by the Nuclear Energy Division of the Department of Energy. Silicon carbide has many potential advantages over traditional zirconium based cladding systems. These include high melting point, low susceptibility to corrosion, and low degradation of mechanical properties under neutron irradiation. In addition, ceramic matrix composites (CMCs) made from SiC have high mechanical toughness enabling these materials to withstand thermal and mechanical shock loading. However, many of the fundamental mechanical and thermal properties of SiC CMCs depend strongly on the fabrication process. As a result, extrapolating current materials science databases for these materials to nuclear applications is not possible. The “Advanced Measurements” work package under the LWRS fuels pathway is tasked with the development of measurement techniques that can characterize fundamental thermal and mechanical properties of SiC CMCs. An emphasis is being placed on development of characterization tools that can used for examination of fresh as well as irradiated samples. The work discuss in this report can be divided into two broad categories. The first involves the development of laser ultrasonic techniques to measure the elastic and yield properties and the second involves the development of laser-based techniques to measurement thermal transport properties. Emphasis has been placed on understanding the anisotropic and heterogeneous nature of SiC CMCs in regards to thermal and mechanical properties. The material properties characterized within this work package will be used as validation of advanced materials physics models of SiC CMCs developed under the LWRS fuels pathway. In addition, it is envisioned that similar measurement techniques can be used to provide process control and quality assurance as well as measurement of in-service degradation. Examples include composite density, distribution of porosity, fiber-matrix bond character, uniformity of weave, physical damage, and joint quality at interface bonds.

Farhad Farzbod; Stephen J. Reese; Zilong Hua; Marat Khafizov; David H. Hurley

2012-08-01T23:59:59.000Z

3

Melt Infiltrated Ceramic Matrix Composites for Shrouds and Combustor Liners of Advanced Industrial Gas Turbines  

SciTech Connect (OSTI)

This report covers work performed under the Advanced Materials for Advanced Industrial Gas Turbines (AMAIGT) program by GE Global Research and its collaborators from 2000 through 2010. A first stage shroud for a 7FA-class gas turbine engine utilizing HiPerComp{reg_sign}* ceramic matrix composite (CMC) material was developed. The design, fabrication, rig testing and engine testing of this shroud system are described. Through two field engine tests, the latter of which is still in progress at a Jacksonville Electric Authority generating station, the robustness of the CMC material and the shroud system in general were demonstrated, with shrouds having accumulated nearly 7,000 hours of field engine testing at the conclusion of the program. During the latter test the engine performance benefits from utilizing CMC shrouds were verified. Similar development of a CMC combustor liner design for a 7FA-class engine is also described. The feasibility of using the HiPerComp{reg_sign} CMC material for combustor liner applications was demonstrated in a Solar Turbines Ceramic Stationary Gas Turbine (CSGT) engine test where the liner performed without incident for 12,822 hours. The deposition processes for applying environmental barrier coatings to the CMC components were also developed, and the performance of the coatings in the rig and engine tests is described.

Gregory Corman; Krishan Luthra; Jill Jonkowski; Joseph Mavec; Paul Bakke; Debbie Haught; Merrill Smith

2011-01-07T23:59:59.000Z

4

Continuous Fiber Ceramic Composites  

SciTech Connect (OSTI)

Fiber-reinforced ceramic composites demonstrate the high-temperature stability of ceramics--with an increased fracture toughness resulting from the fiber reinforcement of the composite. The material optimization performed under the continuous fiber ceramic composites (CFCC) included a series of systematic optimizations. The overall goals were to define the processing window, to increase the robustinous of the process, to increase process yield while reducing costs, and to define the complexity of parts that could be fabricated.

None

2002-09-01T23:59:59.000Z

5

Ceramic-silicide composites  

SciTech Connect (OSTI)

The area of ceramic-silicide composites represents a merging of structural ceramics and structural silicides. Such ceramic-silicide composites can possess the desirable characteristics of both classes of compounds. Important structural ceramics are materials such as Si{sub 3}N{sub 4}, SiC, Al{sub 2}O{sub 3}, and ZrO{sub 2}, which possess covalent, ionic, or mixed covalent-ionic atomic bonding. An important structural silicide is MoSi{sub 2}, which possesses mixed covalent-metallic bonding. The arena of ceramic-silicide composites encompasses both composites where the structural silicide is the matrix and the structural ceramic is the reinforcement, and composites where the structural ceramic is the matrix and the structural silicide is the reinforcement. In the former area, MoSi{sub 2}-SiC, MoSi{sub 2}-ZrO{sub 2}, and MoSi{sub 2}-Al{sub 2}O{sub 3} composites are discussed. In the latter area, Si{sub 3}N{sub 4}-MoSi{sub 2} composites are described.

Petrovic, J.J.

1998-12-01T23:59:59.000Z

6

Alumina-based ceramic composite  

DOE Patents [OSTI]

An improved ceramic composite comprising oxide ceramic particulates, nonoxide ceramic particulates selected from the group consisting of carbides, borides, nitrides of silicon and transition metals and mixtures thereof, and a ductile binder selected from the group consisting of metallic, intermetallic alloys and mixtures thereof is described. The ceramic composite is made by blending powders of the ceramic particulates and the ductile to form a mixture and consolidating the mixture of under conditions of temperature and pressure sufficient to produce a densified ceramic composite.

Alexander, Kathleen B. (Oak Ridge, TN); Tiegs, Terry N. (Lenoir City, TN); Becher, Paul F. (Oak Ridge, TN); Waters, Shirley B. (Knoxville, TN)

1996-01-01T23:59:59.000Z

7

ALS Ceramics Materials Research Advances Engine Performance  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

ALS Ceramics Materials Research Advances Engine Performance ALS Ceramics Materials Research Advances Engine Performance Print Thursday, 27 September 2012 00:00 ritchie ceramics...

8

Method for fabricating ceramic composites  

DOE Patents [OSTI]

A method for producing composite ceramic material is provided wherein a core ceramic structure is produced and simultaneously enveloped with a sleeve of similar material.

Goretta, Kenneth C. (Downers Grove, IL); Singh, Dileep (Naperville, IL); Polzin, Bryant J. (Downers Grove, IL); Cruse, Terry (Lisle, IL); Picciolo, John J. (Lockport, IL)

2002-01-01T23:59:59.000Z

9

Multifracture of ceramic composites  

SciTech Connect (OSTI)

This work presents a mechanistic model for the multifracture process of uniaxially reinforced fibrous ceramic composites under monotonically increasing tension parallel to the fiber direction. The model employs an energy criterion to account for the progression of matrix cracks, bridged by intact fibers, and Weibull failure statistics to relate the failure of the fibers. Consideration is given to the interactions between the foregoing failure processes as well as to the effects of various material parameters on the response of the composite.

Weitsman, Y.J. (Oak Ridge National Lab., TN (United States)); Zhu, H. (Tennessee Univ., Knoxville, TN (United States))

1992-03-01T23:59:59.000Z

10

Alumina-based ceramic composite  

DOE Patents [OSTI]

An improved ceramic composite comprising oxide ceramic particulates, nonoxide ceramic particulates selected from the group consisting of carbides, borides, nitrides of silicon and transition metals and mixtures thereof, and a ductile binder selected from the group consisting of metallic, intermetallic alloys and mixtures thereof is described. The ceramic composite is made by blending powders of the ceramic particulates and the ductile to form a mixture and consolidating the mixture of under conditions of temperature and pressure sufficient to produce a densified ceramic composite. 5 figs.

Alexander, K.B.; Tiegs, T.N.; Becher, P.F.; Waters, S.B.

1996-07-23T23:59:59.000Z

11

Ceramic composite coating  

DOE Patents [OSTI]

A thin, room-temperature-curing, ceramic composite for coating and patching etal substrates comprises a sol gel silica glass matrix filled with finely ground particles or fibers, preferably alumina. The sol gel glass is made by adding ethanol to water to form a first mixture, then separately adding ethanol to tetraethyl orthosilicate to form a second mixture, then slowly adding the first to the second mixture to make a third mixture, and making a slurry by adding the finely ground particles or fibers to the third mixture. The composite can be applied by spraying, brushing or trowelling. If applied to patch fine cracks, densification of the ceramic composite may be obtained to enhance sealing by applying heat during curing.

Wicks, George G. (Aiken, SC)

1997-01-01T23:59:59.000Z

12

Ceramic composite coating  

DOE Patents [OSTI]

A thin, room-temperature-curing, ceramic composite for coating and patching metal substrates comprises a sol gel silica glass matrix filled with finely ground particles or fibers, preferably alumina. The sol gel glass is made by adding ethanol to water to form a first mixture, then separately adding ethanol to tetraethyl orthosilicate to form a second mixture, then slowly adding the first to the second mixture to make a third mixture, and making a slurry by adding the finely ground particles or fibers to the third mixture. The composite can be applied by spraying, brushing or trowelling. If applied to patch fine cracks, densification of the ceramic composite may be obtained to enhance sealing by applying heat during curing.

Wicks, G.G.

1997-01-21T23:59:59.000Z

13

Advanced Ceramic Filter For Diesel Emission Control  

Broader source: Energy.gov (indexed) [DOE]

8 ACM Structure Overview Dow Automotive Advanced Ceramic Cordierite and Silicon carbide Advanced Ceramic Cordierite and Silicon carbide 9272004 DEER2004 9 ACM DPF Chemical...

14

Task 8.9 - Advanced ceramic materials  

SciTech Connect (OSTI)

Advanced ceramic materials such as Continuous Fiber Reinforced Ceramic Matrix Composites (CFCCs) have had promising results on the companion program entitled ``Ceramic Stationary Gas Turbine`` (CSGT). In particular, CFCCs have outperformed monolithic tiles in structural integrity as a combustor liner. Also, CFCCs have provided the higher temperature operation and improved emissions performance that is required for the ATS combustor. The demonstrated advantages on CSGT justified work to explore the use of advanced ceramic composite materials in other gas turbine components. Sub-tasks include development of a practical, cost effective component fabrication process, development of finite element stress analysis to assure 30,000 hours of component life, and fabrication of a demonstration article.

NONE

1997-06-30T23:59:59.000Z

15

Process for producing advanced ceramics  

DOE Patents [OSTI]

A process for the synthesis of homogeneous advanced ceramics such as SiC+AlN, SiAlON, SiC+Al.sub.2 O.sub.3, and Si.sub.3 N.sub.4 +AlN from natural clays such as kaolin, halloysite and montmorillonite by an intercalation and heat treatment method. Included are the steps of refining clays, intercalating organic compounds into the layered structure of clays, drying the intercalated mixture, firing the treated atmospheres and grinding the loosely agglomerated structure. Advanced ceramics produced by this procedure have the advantages of homogeneity, cost effectiveness, simplicity of manufacture, ease of grind and a short process time. Advanced ceramics produced by this process can be used for refractory, wear part and structure ceramics.

Kwong, Kyei-Sing (Tuscaloosa, AL)

1996-01-01T23:59:59.000Z

16

Method for preparing ceramic composite  

DOE Patents [OSTI]

A process is disclosed for preparing ceramic composite comprising blending TiC particulates, Al{sub 2}O{sub 3} particulates and nickel aluminide and consolidating the mixture at a temperature and pressure sufficient to produce a densified ceramic composite having fracture toughness equal to or greater than 7 MPa m{sup 1/2}, a hardness equal to or greater than 18 GPa. 5 figs.

Alexander, K.B.; Tiegs, T.N.; Becher, P.F.; Waters, S.B.

1996-01-09T23:59:59.000Z

17

Method for preparing ceramic composite  

DOE Patents [OSTI]

A process for preparing ceramic composite comprising blending TiC particulates, Al.sub.2 O.sub.3 particulates and nickle aluminide and consolidating the mixture at a temperature and pressure sufficient to produce a densified ceramic composite having fracture toughness equal to or greater than 7 MPa m.sup.1/2, a hardness equal to or greater than 18 GPa.

Alexander, Kathleen B. (Oak Ridge, TN); Tiegs, Terry N. (Lenoir City, TN); Becher, Paul F. (Oak Ridge, TN); Waters, Shirley B. (Knoxville, TN)

1996-01-01T23:59:59.000Z

18

Ceramic composition for immobilization of actinides  

DOE Patents [OSTI]

Disclosed is a ceramic composition for the immobilization of actinides, particularly uranium and plutonium. The ceramic is a titanate material comprising pyrochlore, brannerite and rutile.

Ebbinghaus, Bartley B. (Livermore, CA); Van Konynenburg, Richard A. (Livermore, CA); Vance, Eric R. (Kirrawee, AU); Stewart, Martin W. (Barden Ridge, AU); Jostsons, Adam (Eastwood, AU); Allender, Jeffrey S. (North Augusta, SC); Rankin, David Thomas (Aiken, SC)

2000-01-01T23:59:59.000Z

19

Interfacial studies of refractory glass-ceramic matrix/advanced SiC fiber-reinforced composites. Annual report, 1 Feb 91-1 Feb 92  

SciTech Connect (OSTI)

The main objective of this program is to characterize the chemistry and structure of new advanced small diameter silicon based fibers and how these factors influence the nature of the fiber/matrix interface in refractory glass-ceramic matrix composites. It is the nature of this interface that then determines to a great degree the composite thermal, environmental, and mechanical properties. The fibers under investigation during the second year of this program included the new experimental polymer derived crystalline SiC fibers from Dow Corning Corp., the Si-N-C-O 'Black' fibers from Textron Specialty Materials, as well as the new low oxygen radiation cured Nicalon SiC type fibers from Nippon Carbon Co. Since the availability of all of these fibers was extremely limited, emphasis was placed on the mechanical, chemical, and microstructural characterization of the fibers through tensile testing, SEM of fiber fracture characteristics, scanning Auger depth profiling of fiber surfaces, and TEM of fiber thin sections, as well as their fracture behavior, bonding characteristics, and interfacial compatibility with various glass-ceramic matrix materials. Results of these analyses are discussed. Crystalline SiC fibers, Textron 'Black' fibers, low oxygen Nicalon fibers, SiC fiber/glass-ceramic matrix interfaces, TEM fiber analyses.

Brennan, J.J.

1992-04-30T23:59:59.000Z

20

BIOMIMETIC PROCESSING OF CERAMICS AND CERAMIC-METAL COMPOSITES  

E-Print Network [OSTI]

625 BIOMIMETIC PROCESSING OF CERAMICS AND CERAMIC-METAL COMPOSITES M. YASREBI, G. H. KIM, K. E of composite materials has become popular and frequently necessary to meet the requirements of technology. The employment of composites is well appreciated firom the fact that unique arrangements of constituent materials

Aksay, Ilhan A.

Note: This page contains sample records for the topic "advanced ceramic composites" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

High impact resistant ceramic composite  

DOE Patents [OSTI]

A ceramic material and a method of forming a ceramic material which possesses a high impact resistance are disclosed. The material comprises: (a) a first continuous phase of [beta]-SiC; and (b) a second phase of about 25-40 vol % TiB[sub 2]. Al[sub 2]O[sub 3] is preferably used as a densification aid. The material is formed by hot-pressing the mixture at a temperature from greater than about 1800 C to less than the transition temperature of [beta]-SiC to [alpha]-SiC. The hot-pressing is performed at a pressure of about 2000 psi to about 4000 psi in an inert atmosphere for several hours and results in the formation of a two phase sintered ceramic composite material. 6 figures.

Derkacy, J.A.

1991-07-16T23:59:59.000Z

22

Ceramic Technology for Advanced Heat Engines Project  

SciTech Connect (OSTI)

The Ceramic Technology For Advanced Heat Engines Project was developed by the Department of Energy's Office of Transportation Systems (OTS) in Conservation and Renewable Energy. This project, part of the OTS's Advanced Materials Development Program, was developed to meet the ceramic technology requirements of the OTS's automotive technology programs. Significant accomplishments in fabricating ceramic components for the Department of Energy (DOE), National Aeronautics and Space Administration (NASA), and Department of Defense (DOD) advanced heat engine programs have provided evidence that the operation of ceramic parts in high-temperature engine environments is feasible. However, these programs have also demonstrated that additional research is needed in materials and processing development, design methodology, and data base and life prediction before industry will have a sufficient technology base from which to produce reliable cost-effective ceramic engine components commercially. An assessment of needs was completed, and a five year project plan was developed with extensive input from private industry. The objective of the project is to develop the industrial technology base required for reliable ceramics for application in advanced automotive heat engines. The project approach includes determining the mechanisms controlling reliability, improving processes for fabricating existing ceramics, developing new materials with increased reliability, and testing these materials in simulated engine environments to confirm reliability. Although this is a generic materials project, the focus is on structural ceramics for advanced gas turbine and diesel engines, ceramic hearings and attachments, and ceramic coatings for thermal barrier and wear applications in these engines.

Not Available

1990-08-01T23:59:59.000Z

23

Advanced Ceramic Materials and Packaging Technologies for Realizing...  

Broader source: Energy.gov (indexed) [DOE]

Advanced Ceramic Materials and Packaging Technologies for Realizing Sensors for Concentrating Solar Power Systems Advanced Ceramic Materials and Packaging Technologies for...

24

Low temperature joining of ceramic composites  

DOE Patents [OSTI]

A method of joining similar or dissimilar ceramic and ceramic composite materials, such as SiC continuous fiber ceramic composites, at relatively low joining temperatures uses a solventless, three component bonding agent effective to promote mechanical bond toughness and elevated temperature strength to operating temperatures of approximately 1200 C. The bonding agent comprises a preceramic precursor, an aluminum bearing powder, such as aluminum alloy powder, and mixtures of aluminum metal or alloy powders with another powder, and boron powder in selected proportions. The bonding agent is disposed as an interlayer between similar or dissimilar ceramic or ceramic composite materials to be joined and is heated in ambient air or inert atmosphere to a temperature not exceeding about 1200 C to form a strong and tough bond joint between the materials. The bond joint produced is characterized by a composite joint microstructure having relatively soft, compliant aluminum bearing particulate regions dispersed in a ceramic matrix. 3 figs.

Barton, T.J.; Anderson, I.E.; Ijadi-Maghsoodi, S.; Nosrati, M.; Unal, O.

1999-07-13T23:59:59.000Z

25

Low temperature joining of ceramic composites  

DOE Patents [OSTI]

A method of joining similar or dissimilar ceramic and ceramic composite materials, such as SiC continuous fiber ceramic composites, at relatively low joining temperatures uses a solventless, three component bonding agent effective to promote mechanical bond toughness and elevated temperature strength to operating temperatures of approximately 1200 degrees C. The bonding agent comprises a preceramic precursor, an aluminum bearing powder, such as aluminum alloy powder, and mixtures of aluminum metal or alloy powders with another powder, and boron powder in selected proportions. The bonding agent is disposed as an interlayer between similar or dissimilar ceramic or ceramic composite materials to be joined and is heated in ambient air or inert atmosphere to a temperature not exceeding about 1200 degrees C. to form a strong and tough bond joint between the materials. The bond joint produced is characterized by a composite joint microstructure having relatively soft, compliant aluminum bearing particulate regions dispersed in a ceramic matrix. 3 figs.

Barton, T.J.; Anderson, I.E.; Ijadi-Maghsoodi, S.; Nosrati, M.; Unal, O.

1999-01-12T23:59:59.000Z

26

Low temperature joining of ceramic composites  

DOE Patents [OSTI]

A method of joining similar or dissimilar ceramic and ceramic composite materials, such as SiC continuous fiber ceramic composites, at relatively low joining temperatures uses a solventless, three component bonding agent effective to promote mechanical bond toughness and elevated temperature strength to operating temperatures of approximately 1200 degrees C. The bonding agent comprises a preceramic precursor, an aluminum bearing powder, such as aluminum alloy powder, and mixtures of aluminum metal or alloy powders with another powder, and and boron powder in selected proportions. The bonding agent is disposed as an interlayer between similar or dissimilar ceramic or ceramic composite materials to be joined and is heated in ambient air or inert atmosphere to a temperature not exceeding about 1200 degrees C. to form a strong and tough bond joint between the materials. The bond joint produced is characterized by a composite joint microstructure having relatively soft, compliant aluminum bearing particulate regions dispersed in a ceramic matrix.

Barton, Thomas J. (Ames, IA); Anderson, Iver E. (Ames, IA); Ijadi-Maghsoodi, Sina (Ames, IA); Nosrati, Mohammad (Ames, IA); Unal, Ozer (Ames, IA)

1999-07-13T23:59:59.000Z

27

Ceramic technology for Advanced Heat Engines Project  

SciTech Connect (OSTI)

Significant accomplishments in fabricating ceramic components for advanced heat engine programs have provided evidence that the operation of ceramic parts in high-temperature engine environments is feasible. However, these programs have also demonstrated that additional research is needed in materials and processing development, design methodology, and database and life prediction before industry will have a sufficient technology base from which to produce reliable cost-effective ceramic engine components commercially. An assessment of needs was completed, and a five year project plan was developed with extensive input from private industry. The project approach includes determining the mechanisms controlling reliability, improving processes for fabricating existing ceramics, developing new materials with increased reliability, and testing these materials in simulated engine environments to confirm reliability. Although this is a generic materials project, the focus is on the structural ceramics for advanced gas turbine and diesel engines, ceramic bearings and attachments, and ceramic coatings for thermal barrier and wear applications in these engines. To facilitate the rapid transfer of this technology to US industry, the major portion of the work is being done in the ceramic industry, with technological support from government laboratories, other industrial laboratories, and universities. This project is managed by ORNL for the Office of Transportation Technologies, Office of Transportation Materials, and is closely coordinated with complementary ceramics tasks funded by other DOE offices, NASA, DOD, and industry.

Johnson, D.R.

1991-07-01T23:59:59.000Z

28

ADVANCED SECOND GENERATION CERAMIC CANDLE FILTERS  

SciTech Connect (OSTI)

Through sponsorship from the Department of Energy's National Energy Technology Laboratory (DOE/NETL), development and manufacture of advanced second generation candle filters was undertaken in the early 1990's. Efforts were primarily focused on the manufacture of fracture toughened, 1.5 m, continuous fiber ceramic composite (CFCC) and filament wound candle filters by 3M, McDermott, DuPont Lanxide Composites, and Techniweave. In order to demonstrate long-term thermal, chemical, and mechanical stability of the advanced second generation candle filter materials, Siemens Westinghouse initiated high temperature, bench-scale, corrosion testing of 3M's CVI-SiC and DuPont's PRD-66 mini-candles, and DuPont's CFCC SiC-SiC and IF&P Fibrosic{sup TM} coupons under simulated, pressurized fluidized-bed combustion (PFBC) conditions. This effort was followed by an evaluation of the mechanical and filtration performance of the advanced second generation filter elements in Siemens Westinghouse's bench-scale PFBC test facility in Pittsburgh, Pennsylvania. Arrays of 1.4-1.5 m 3M CVI-SiC, DuPont PRD-66, DuPont SiC-SiC, and IF&P Fibrosic{sup TM} candles were subjected to steady state process operating conditions, increased severity thermal transients, and accelerated pulse cycling test campaigns which represented {approx}1760 hours of equivalent filter operating life. Siemens Westinghouse subsequently participated in early material surveillance programs which marked entry of the 3M CVI-SiC and DuPont PRD-66 candle filters in Siemens Westinghouse Advanced Particulate Filtration (APF) system at the American Electric Power (AEP) Tidd Demonstration Plant in Brilliant, Ohio. Siemens Westinghouse then conducted an extended, accelerated life, qualification program, evaluating the performance of the 3M, McDermott, and Techniweave oxide-based CFCC filter elements, modified DuPont PRD-66 elements, and the Blasch, Scapa Cerafil{sup TM}, and Specific Surface monolithic candles for use in the APF system at the Foster Wheeler pressurized circulating fluidized-bed combustion (PCFBC), pilot-scale, test facility in Karhula, Finland. This report presents a summary of these efforts, defining the stability of the various porous ceramic filter materials, as well as component performance and extended life for use in advanced coal-based power systems.

M.A. Alvin

2002-01-31T23:59:59.000Z

29

Low temperature joining of ceramic composites  

DOE Patents [OSTI]

A method of joining similar or dissimilar ceramic and ceramic composite materials, such as SiC continuous fiber ceramic composites, at relatively low joining temperatures uses a solventless, three component bonding agent effective to promote mechanical bond toughness and elevated temperature strength to operating temperatures of approximately 1200 degrees C. The bonding agent comprises a preceramic precursor, an aluminum bearing powder, such as aluminum alloy powder, and mixtures of aluminum metal or alloy powders with another powder, and and boron powder in selected proportions. The bonding agent is disposed as an interlayer between similar or dissimilar ceramic or cermaic composite materials to be joined and is heated in ambient air or inert atmosphere to a temperature not exceeding about 1200 degrees C. to form a strong and tough bond joint between the materials. The bond joint produced is characterized by a composite joint microstructure having relatively soft, compliant aluminum bearing particulate regions dispersed in a ceramic matrix.

Barton, Thomas J. (Ames, IA); Anderson, Iver E. (Ames, IA); Ijadi-Maghsoodi, Sina (Ames, IA); Nosrati, Mohammad (Ames, IA); Unal, Ozer (Ames, IA)

2001-04-10T23:59:59.000Z

30

Low temperature joining of ceramic composites  

DOE Patents [OSTI]

A method of joining similar or dissimilar ceramic and ceramic composite materials, such as SiC continuous fiber ceramic composites, at relatively low joining temperatures uses a solventless, three component bonding agent effective to promote mechanical bond toughness and elevated temperature strength to operating temperatures of approximately 1200 degrees C. The bonding agent comprises a preceramic precursor, an aluminum bearing powder, such as aluminum alloy powder, and mixtures of aluminum metal or alloy powders with another powder, and and boron powder in selected proportions. The bonding agent is disposed as an interlayer between similar or dissimilar ceramic or cermaic composite materials to be joined and is heated in ambient air or inert atmosphere to a temperature not exceeding about 1200 degrees C. to form a strong and tough bond joint between the materials. The bond joint produced is characterized by a composite joint microstructure having relatively soft, compliant aluminum bearing particulate regions dispersed in a ceramic matrix.

Barton, Thomas J. (Ames, IA); Anderson, Iver E. (Ames, IA); Ijadi-Maghsoodi, Sina (Ames, IA); Nosrati, Mohammad (Ames, IA); Unal, Ozer (Ames, IA)

1999-01-12T23:59:59.000Z

31

Continuous Fiber Ceramic Composites (CFCC)  

SciTech Connect (OSTI)

This report summarizes work to develop CFCC's for various applications in the Industries of the Future (IOF) and power generation areas. Performance requirements range from relatively modest for hot gas filters to severe for turbine combustor liners and infrared burners. The McDermott Technology Inc. (MTI) CFCC program focused on oxide/oxide composite systems because they are known to be stable in the application environments of interest. The work is broadly focused on dense and porous composite systems depending on the specific application. Dense composites were targeted at corrosion resistant components, molten aluminum handling components and gas turbine combustor liners. The development work on dense composites led to significant advances in fiber coatings for oxide fibers and matrix densification. Additionally, a one-step fabrication process was developed to produce low cost composite components. The program also supported key developments in advanced oxide fibers that resulted in an improved version of Nextel 610 fiber (commercially available as Nextel 650) and significant progress in the development of a YAG/alumina fiber. Porous composite development focused on the vacuum winding process used to produce hot gas filters and infrared burner components.

R. A. Wagner

2002-12-18T23:59:59.000Z

32

Method of making multilayered titanium ceramic composites  

DOE Patents [OSTI]

A method making a titanium ceramic composite involves forming a hot pressed powder body having a microstructure comprising at least one titanium metal or alloy layer and at least one ceramic particulate reinforced titanium metal or alloy layer and hot forging the hot pressed body follwed by hot rolling to substantially reduce a thickness dimension and substantially increase a lateral dimension thereof to form a composite plate or sheet that retains in the microstructure at least one titanium based layer and at least one ceramic reinforced titanium based layer in the thickness direction of the composite plate or sheet.

Fisher, George T., II; Hansen; Jeffrey S.; Oden; Laurance L.; Turner; Paul C.; Ochs; Thomas L.

1998-08-25T23:59:59.000Z

33

Advanced ceramic cladding for water reactor fuel  

SciTech Connect (OSTI)

Under the US Department of Energy's Nuclear Energy Research Initiatives (NERI) program, continuous fiber ceramic composites (CFCCs) are being developed as cladding for water reactor fuel elements. The purpose is to substantially increase the passive safety of water reactors. A development effort was initiated in 1991 to fabricate CFCC-clad tubes using commercially available fibers and a sol-gel process developed by McDermott Technologies. Two small-diameter CFCC tubes were fabricated using pure alumina and alumina-zirconia fibers in an alumina matrix. Densities of {approximately}60% of theoretical were achieved. Higher densities are required to guarantee fission gas containment. This NERI work has just begun, and only preliminary results are presented herein. Should the work prove successful, further development is required to evaluate CFCC cladding and performance, including in-pile tests containing fuel and exploring a marriage of CFCC cladding materials with suitable advanced fuel and core designs. The possibility of much higher temperature core designs, possibly cooled with supercritical water, and achievement of plant efficiencies {ge}50% would be examined.

Feinroth, H.

2000-07-01T23:59:59.000Z

34

Continuous fiber ceramic composites-- A new generation of materials for industrial and corrosive applications  

SciTech Connect (OSTI)

The market for advanced ceramics is very large and growing rapidly, at a rate of 20% per year. These materials are characterized by their excellent high temperature properties. They are finding use where temperatures exceed the capability of other materials, especially metals. Even so, they are not selected for many applications because of the brittleness of monolithic ceramics. In the search for improvement, material scientists reinforce ceramics with continuous ceramic fibers, such as silicon carbide. Embedded continuous ceramic fibers reinforce the ceramic matrix by deflecting and bridging fractures. These continuous fiber ceramic composite (CFCC) materials offer the advantages of ceramics--resistance to heat, erosion, and corrosion--while adding toughness and thermal shock resistance. CFCC materials are evolving to the advanced product development stage with Department of Energy support in the CFCC program. Designers are evaluating them in corrosive applications in major industries. Various CFCC's are described and several case studies of CVI SiC/SiC application testing are reviewed.

Craig, P.A.

1999-07-01T23:59:59.000Z

35

High temperature insulation for ceramic matrix composites  

SciTech Connect (OSTI)

A ceramic composition is provided to insulate ceramic matrix composites under high temperature, high heat flux environments. The composite comprises a plurality of hollow oxide-based spheres of varios dimentions, a phosphate binder, and at least one oxide filler powder, whereby the phosphate binder partially fills gaps between the spheres and the filler powders. The spheres are situated in the phosphate binder and the filler powders such that each sphere is in contact with at least one other sphere. The spheres may be any combination of Mullite spheres, Alumina spheres, or stabilized Zirconia spheres. The filler powder may be any combination of Alumina, Mullite, Ceria, or Hafnia. Preferably, the phosphate binder is Aluminum Ortho-Phosphate. A method of manufacturing the ceramic insulating composition and its application to CMC substates are also provided.

Merrill, Gary B. (Monroeville, PA); Morrison, Jay Alan (Orlando, FL)

2000-01-01T23:59:59.000Z

36

High temperature insulation for ceramic matrix composites  

DOE Patents [OSTI]

A ceramic composition is provided to insulate ceramic matrix composites under high temperature, high heat flux environments. The composition comprises a plurality of hollow oxide-based spheres of various dimensions, a phosphate binder, and at least one oxide filler powder, whereby the phosphate binder partially fills gaps between the spheres and the filler powders. The spheres are situated in the phosphate binder and the filler powders such that each sphere is in contact with at least one other sphere. The spheres may be any combination of Mullite spheres, Alumina spheres, or stabilized Zirconia spheres. The filler powder may be any combination of Alumina, Mullite, Ceria, or Hafnia. Preferably, the phosphate binder is Aluminum Ortho-Phosphate. A method of manufacturing the ceramic insulating composition and its application to CMC substrates are also provided.

Merrill, Gary B.; Morrison, Jay Alan

2004-01-13T23:59:59.000Z

37

High temperature insulation for ceramic matrix composites  

SciTech Connect (OSTI)

A ceramic composition is provided to insulate ceramic matrix composites under high temperature, high heat flux environments. The composition comprises a plurality of hollow oxide-based spheres of various dimensions, a phosphate binder, and at least one oxide filler powder, whereby the phosphate binder partially fills gaps between the spheres and the filler powders. The spheres are situated in the phosphate binder and the filler powders such that each sphere is in contact with at least one other sphere. The spheres may be any combination of Mullite spheres, Alumina spheres, or stabilized Zirconia spheres. The filler powder may be any combination of Alumina, Mullite, Ceria, or Hafnia. Preferably, the phosphate binder is Aluminum Ortho-Phosphate. A method of manufacturing the ceramic insulating composition and its application to CMC substrates are also provided.

Merrill, Gary B. (Monroeville, PA); Morrison, Jay Alan (Orlando, FL)

2001-01-01T23:59:59.000Z

38

Batch compositions for cordierite ceramics  

DOE Patents [OSTI]

Ceramic products consisting principally of cordierite and a method for making them are provided, the method employing batches comprising a mineral component and a chemical component, the mineral component comprising clay and talc and the chemical component consisting essentially of a combination of the powdered oxides, hydroxides, or hydrous oxides of magnesium, aluminum and silicon. Ceramics made by extrusion and firing of the batches can exhibit low porosity, high strength and low thermal expansion coefficients.

Hickman, David L. (Big Flats, NY)

1994-07-26T23:59:59.000Z

39

Ceramic technology for advanced heat engines project  

SciTech Connect (OSTI)

The Ceramic Technology for Advanced Heat Engines Project was developed by the Department of Energy's Office of Transportation Systems in Conservation and Renewable Energy. This project was developed to meet the ceramic technology requirements of the OTT's automotive technology programs. This project is managed by ORNL and is closely coordinated with complementary ceramics tasks funded by other DOE offices, NASA, DoD, and industry. Research is discussed under the following topics; Turbomilling of SiC Whiskers; microwave sintering of silicon nitride; and milling characterization; processing of monolithics; silicon nitride matrix; oxide matrix; silicate matrix; thermal and wear coatings; joining; design; contact interfaces; time-dependent behavior; environmental effects; fracture mechanics; nondestructive evaluation; and technology transfer. References, figures, and tables are included with each topic.

Not Available

1990-09-01T23:59:59.000Z

40

A novel biomimetic approach to the design of high-performance ceramic/metal composites  

E-Print Network [OSTI]

In  particular,  ceramic?matrix  composites  (CMCs)  are M.   2006  Ceramic  and  metal  matrix  composites:  Routes 

Launey, Maximilien E.

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "advanced ceramic composites" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

A novel biomimetic approach to the design of high-performance ceramic/metal composites  

E-Print Network [OSTI]

Rosso,  M.   2006  Ceramic  and  metal  matrix  composites: In  particular,  ceramic?matrix  composites  (CMCs)  are 

Launey, Maximilien E.

2010-01-01T23:59:59.000Z

42

Composite treatment of ceramic tile armor  

DOE Patents [OSTI]

An improved ceramic tile armor has a core of boron nitride and a polymer matrix composite (PMC) facing of carbon fibers fused directly to the impact face of the tile. A polyethylene fiber composite backing and spall cover are preferred. The carbon fiber layers are cured directly onto the tile, not adhered using a separate adhesive so that they are integral with the tile, not a separate layer.

Hansen, James G. R. (Oak Ridge, TN); Frame, Barbara J. (Oak Ridge, TN)

2012-01-02T23:59:59.000Z

43

Composite treatment of ceramic tile armor  

DOE Patents [OSTI]

An improved ceramic tile armor has a core of boron nitride and a polymer matrix composite (PMC) facing of carbon fibers fused directly to the impact face of the tile. A polyethylene fiber composite backing and spall cover are preferred. The carbon fiber layers are cured directly onto the tile, not adhered using a separate adhesive so that they are integral with the tile, not a separate layer.

Hansen, James G. R. (Oak Ridge, TN) [Oak Ridge, TN; Frame, Barbara J. (Oak Ridge, TN) [Oak Ridge, TN

2010-12-14T23:59:59.000Z

44

Advanced Ceramic Materials and Packaging Technologies for Realizing...  

Broader source: Energy.gov (indexed) [DOE]

November 15, 2012 Advanced Ceramic Materials and Packaging Technologies for Realizing Sensors for Concentrating Solar Power Systems PROPRIETARY INFORMATION This document...

45

Mechanical Properties of Porous-Matrix Ceramic Composites**  

E-Print Network [OSTI]

REVIEWS Mechanical Properties of Porous- Matrix Ceramic Composites** By Frank W. Zok* and Carlos G/Mechanical Properties of Porous-Matrix Ceramic Composites REVIEWS The porous matrix concept has been developed primarily. Levi 1. Introduction Damage tolerance can be enabled in continuous fiber-rein- forced ceramic

Zok, Frank

46

NDE (nondestructive examination) development for ceramics for advanced heat engines  

SciTech Connect (OSTI)

The Department of Energy (DOE) Ceramic Technology for Advanced Heat Engines (CTAHE) project was initiated in 1983 to meet the ceramic technology needs of DOE's advanced heat engines programs (i.e., advanced gas turbines and low heat rejection diesels). The objective is to establish an industrial ceramic technology base for reliable and cost-effective high-temperature components. Reliability of ceramics was recognized as the major technology need. To increase the material reliability of current and new ceramics, advances were needed in component design methodology, materials processing technology, and data base/life prediction. Nondestructive examination (NDE) was identified as one of the key elements in the approach to high-reliability components. An assessment was made of the current status of NDE for structural ceramics, and a report was prepared containing the results and recommendations for needed development. Based on these recommendations, a long-range NDE development program has been established in the CTAHE project to address these needs.

McClung, R.W. (McClung (R.W.), Powell, TN (USA)); Johnson, D.R. (Oak Ridge National Lab., TN (USA))

1991-01-01T23:59:59.000Z

47

Composites (CFCCs) for low cost energy and cleaner environment. Continuous fiber ceramic composites program  

SciTech Connect (OSTI)

For many industrial applications, materials are desired which combine light weight, high temperature strength, and stability in corrosive environments. Among competing materials, ceramics are noteworthy candidates for such applications. The use of ceramics is often constrained, however, by brittleness; i.e., low toughness. Ceramic composites are being developed to overcome this limitation. With recent advances in ceramic fiber technology, it is possible to design a composite material based on continuous ceramic fibers embedded in a ceramic matrix. The use of ceramic composites in industrial applications will result in reduced fuel consumption, but will also prevent airborne pollution (principally NO, SO{sub x}, CO{sub 2}, and particulates), and economically benefit the end user through energy and environmental savings and increased competitiveness. Industry will also benefit through increased productivity and consumers will benefit through lower energy and environmental costs and a cleaner environment. The development and use of CFCCs could become an important factor in the international competitiveness of U.S. industry. CFCCs will be a critical enabling material in the design and engineering of advanced components, systems, and processes. If CFCC technology is developed outside the United States, domestic users of these materials may be forced to rely on foreign suppliers of the products fabricated from CFCCs, as well as the materials themselves. Foreign countries, including Japan and France, have embarked on government-supported CFCC development efforts. With the market for CFCC products expected to be a $10 billion dollar market by 2010, CFCC development will be important for the competitiveness of U.S. industry and for retaining and creating jobs for U.S. citizens. This document summarizes the potential energy, environmental, and economic benefits that CFCCs will have for the U.S. economy and particularly for the industrial sector.

Not Available

1994-02-01T23:59:59.000Z

48

Structural Ceramic Composites for Nuclear Applications  

SciTech Connect (OSTI)

A research program has been established to investigate fiber reinforced ceramic composites to be used as control rod components within a Very High Temperature Reactor. Two candidate systems have been identified, carbon fiber reinforced carbon (Cf/C) and silicon carbide fiber reinforced silicon carbide (SiCf/SiC) composites. Initial irradiation stability studies to determine the maximum dose for each composite type have been initiated within the High Flux Isotope Reactor at Oak Ridge National Laboratory. Test samples exposed to 10 dpa irradiation dose have been completed with future samples to dose levels of 20 and 30 dpa scheduled for completion in following years. Mechanical and environmental testing is being conducted concurrently at the Idaho National Laboratory and at Pacific Northwest National Laboratory. High temperature test equipment, testing methodologies, and test samples for high temperature (up to 1600º C) tensile strength and long duration creep studies have been established. Specific attention was paid to the architectural fiber preform design as well as the materials used in construction of the composites. Actual testing of both tubular and flat, "dog-bone" shaped tensile composite specimens will begin next year. Since there is no precedence for using ceramic composites within a nuclear reactor, ASTM standard test procedures will be established from these mechanical and environmental tests. Close collaborations between the U.S. national laboratories and international collaborators (i.e. France and Japan) are being forged to establish both national and international test standards to be used to qualify ceramic composites for nuclear reactor applications.

William Windes; P.A. Lessing; Y. Katoh; L. L. Snead; E. Lara-Curzio; J. Klett; C. Henager, Jr.; R. J. Shinavski

2005-08-01T23:59:59.000Z

49

Ceramic oxide composite hot gas filters  

SciTech Connect (OSTI)

This paper describes the development and testing of continuous fiber ceramic composites (CFCC) based hot gas filters. The work was divided into three primary tasks. In the first task, a preliminary set of compositions was fabricated in the form of open end tubes and characterized. The results of the first task were then used to identify the most promising compositions for sub-scale fabrication and testing. In addition to laboratory measurements of permeability and strength, exposure testing in a coal combustion environment was performed to assess the thermo-chemical stability of the CFCC materials. The results of this testing were used to down-select the filter composition for full-scale filter fabrication and testing in the third phase of the program.

Wagner, R.A.; Weitzel, P. [Babcock and Wilcox, Lynchburg, VA (United States)

1996-12-31T23:59:59.000Z

50

Process for making a ceramic composition for immobilization of actinides  

DOE Patents [OSTI]

Disclosed is a process for making a ceramic composition for the immobilization of actinides, particularly uranium and plutonium. The ceramic is a titanate material comprising pyrochlore, brannerite and rutile. The process comprises oxidizing the actinides, milling the oxides to a powder, blending them with ceramic precursors, cold pressing the blend and sintering the pressed material.

Ebbinghaus, Bartley B. (Livermore, CA); Van Konynenburg, Richard A. (Livermore, CA); Vance, Eric R. (Kirrawee, AU); Stewart, Martin W. (Barden Ridge, AU); Walls, Philip A. (Cronulla, AU); Brummond, William Allen (Livermore, CA); Armantrout, Guy A. (Livermore, CA); Herman, Connie Cicero (Pleasanton, CA); Hobson, Beverly F. (Livermore, CA); Herman, David Thomas (Pleasanton, CA); Curtis, Paul G. (Tracy, CA); Farmer, Joseph (Tracy, CA)

2001-01-01T23:59:59.000Z

51

Fracture behavior of advanced ceramic hot gas filters: Final report  

SciTech Connect (OSTI)

This report presents the results of mechanical/microstructural evaluation, thermal shock/fatigue testing, and stress analyses of advanced hot-gas filters obtained from different manufacturers. These filters were fabricated from both monolithic ceramics and composites. The composite filters, made of both oxide and nonoxide materials, were in both as-fabricated and exposed conditions, whereas the monolithic filters were made only of nonoxide materials. Mechanical property measurement of composite filters included diametral compression testing with O-ring specimens and burst-testing of short filter segments with rubber plugs. In-situ strength of fibers in the composite filters was evaluated by microscopic technique. Thermal shock/fatigue resistance was estimated by measuring the strengths of filter specimens before and after thermal cycling from an air environment at elevated temperatures to a room temperature oil bath. Filter performance during mechanical and thermal shock/fatigue loadings was correlated with microstructural observations. Micromechanical models were developed to derive properties of composite filter constituents on the basis of measured mechanical properties of the filters. Subsequently, these properties were used to analytically predict the performance of composite filters during thermal shock loading.

Singh, J.P.; Majumdar, S.; Sutaria, M.; Bielke, W. [Argonne National Lab., IL (United States). Energy Technology Div.

1997-03-01T23:59:59.000Z

52

Conductive ceramic composition and method of preparation  

DOE Patents [OSTI]

A ceramic anode composition is formed of a multivalent metal oxide or oxygenate such as an alkali metal, transition metal oxygenate. The anode is prepared as a non-stoichiometric crystalline structure by reaction and conditioning in a hydrogen gas cover containing minor proportions of carbon dioxide and water vapor. The structure exhibits a single phase and substantially enhanced electrical conductivity over that of the corresponding stoichiometric structure. Unexpectedly, such oxides and oxygenates are found to be stable in the reducing anode fuel gas of a molten carbonate fuel cell.

Smith, James L. (Lemont, IL); Kucera, Eugenia H. (Downers Grove, IL)

1991-01-01T23:59:59.000Z

53

Conductive ceramic composition and method of preparation  

DOE Patents [OSTI]

A ceramic anode composition is formed of a multivalent metal oxide or oxygenate such as an alkali metal, transition metal oxygenate. The anode is prepared as a non-stoichiometric crystalline structure by reaction and conditioning in a hydrogen gas cover containing minor proportions of carbon dioxide and water vapor. The structure exhibits a single phase and substantially enhanced electrical conductivity over that of the corresponding stoichiometric structure. Unexpectedly, such oxides and oxygenates are found to be stable in the reducing anode fuel gas of a molten carbonate fuel cell. 4 figures.

Smith, J.L.; Kucera, E.H.

1991-04-16T23:59:59.000Z

54

advanced ceramic materials: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

ceramic materials First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Design with Advanced Ceramics Course...

55

Joining of 6061 Aluminum Matrix-Ceramic Particle Reinforced Composites  

E-Print Network [OSTI]

) ) Joining of 6061 Aluminum Matrix-Ceramic Particle Reinforced Composites by R. Kiehn and T. W................... .. ....... ... ... 3 Literature Review ......... ...... ..... ... . . 3 Conventional Aluminum Brazing ........ 4 Aluminum Composite Joining ........... 5 Aluminum Joining by Unconventional Methods

Eagar, Thomas W.

56

High Temperature Tolerant Ceramic Composites Having Porous Interphases  

SciTech Connect (OSTI)

In general, this invention relates to a ceramic composite exhibiting enhanced toughness and decreased brittleness, and to a process of preparing the ceramic composite. The ceramic composite comprises a first matrix that includes a first ceramic material, preferably selected from the group including alumina (Al2O3), mullite (3Al2O3.2SiO2), yttrium aluminate garnet (YAG), yttria stabilized zirconia (YSZ), celsian (BaAl2Si2O8) and nickel aluminate (NiAl2O4). The ceramic composite also includes a porous interphase region that includes a substantially non-sinterable material. The non-sinterable material can be selected to include, for example, alumina platelets. The platelets lie in random 3-D orientation and provide a debonding mechanism, which is independent of temperature in chemically compatible matrices. The non-sinterable material induces constrained sintering of a ceramic powder resulting in permanent porosity in the interphase region. For high temperature properties, addition of a sinterable ceramic powder to the non-sinterable material provides sufficiently weak debonding interphases. The ceramic composite can be provided in a variety of forms including a laminate, a fibrous monolith, and a fiber-reinforced ceramic matrix. In the laminated systems, intimate mixing of strong versus tough microstructures were tailored by alternating various matrix-to-interphase thickness ratios to provide the bimodal laminate.

Kriven, Waltraud M. (Champaign, IL); Lee, Sang-Jin (Chonnam, KR)

2005-05-03T23:59:59.000Z

57

Interfacial chemistry and structure in ceramic composites  

SciTech Connect (OSTI)

The interfacial chemistry and structure of ceramic matrix composites (CMCs) play a major role in the properties of these materials. Fiber-matrix interfaces chemistries are vitally important in the fracture strength, fracture toughness, and fracture resistance of ceramic composites because they influence fiber loading and fiber pullout. Elevated-temperature properties are also linked to the interfacial characteristics through the chemical stability of the interface in corrosive environments and the creep/pullout behavior of the interface. Physical properties such as electrical and thermal conductivity are also dependent on the interface. Fiber-matrix interfaces containing a 1-{mu}m-thick multilayered interface with amorphous and graphitic C to a 1-nm-thick SiO{sub 2} layer can result from sintering operations for some composite systems. Fibers coated with C, BN, C/BC/BN, and Si are also used to produce controlled interface chemistries and structures. Growth interfaces within the matrix resulting from processing of CMCs can also be crucial to the behavior of these materials. Evaluation of the interfacial chemistry and structure of CMCs requires the use of a variety of analytical tools, including optical microscopy, scanning electron microscopy, Auger electron spectroscopy, and transmission electron microscopy coupled with energy dispersive x-ray analysis. A review of the interfacial chemistry and structure of SiC whisker- and fiber-reinforced Si{sub 3}N{sub 4} and SiC/SiC materials is presented. Where possible, correlations with fracture properties and high-temperature stability are made. 94 refs., 10 figs.

Jones, R.H.; Saenz, N.T.; Schilling, C.H.

1990-09-01T23:59:59.000Z

58

Overview of ASTM standard activities in support of advanced structural ceramics development  

SciTech Connect (OSTI)

An overview is presented of the activities of ASTM Committee C-28 on Advanced Ceramics. This activity originated in 1986 when it became apparent that advanced ceramics were being considered for extensive use in applications such as advanced heat engines, heat exchangers, combustors, etc. in aerospace and energy conservation activities. These applications require optimum material behavior with physical and mechanical property reproducibility, component reliability, and well defined methods of data treatment and material analysis for both monolithic and composite ceramic materials. As new materials are introduced into the market place, these issues are best dealt with via standard methods. Therefore, a progress report is given describing activities of the five standard writing subcommittees who support the ASTM Committee C-28 effort. Accomplishments to date are given, as well as likely future activities, including a brief summary of joint cooperative efforts with international standard formulating organizations.

Brinkman, C.R. [Oak Ridge National Lab., TN (United States); Quinn, G.D. [NIST, Gaithersburg, MD (United States); McClung, R.W.

1995-07-01T23:59:59.000Z

59

Development and application of NDE methods for monolithic and continuous fiber ceramic matrix composites.  

SciTech Connect (OSTI)

Monolithic structural ceramics and continuous fiber ceramic matrix composites (CMCs) are being developed for application in many thermally and chemically aggressive environments where structural reliability is paramount. We have recently developed advanced nondestructive evaluation (NDE) methods that can detect distributed ''defects'' such as density gradients and machining-induced damage in monolithic materials, as well as delamination, porosity, and throughwall cracks, in CMC materials. These advanced NDE methods utilize (a) high-resolution, high-sensitivity thermal imaging; (b) high-resolution X-ray imaging; (c) laser-based elastic optical scattering; (d) acoustic resonance; (e) air-coupled ultrasonic methods; and (f) high-sensitivity fluorescent penetrant technology. This paper discusses the development and application of these NDE methods relative to ceramic processing and ceramic components used in large-scale industrial gas turbines and hot gas filters for gas stream particulate cleanup.

Ellingson, W. A.

1999-05-21T23:59:59.000Z

60

Probabilistic Failure Analysis for Wound Composite Ceramic Cladding Assembly  

SciTech Connect (OSTI)

Advanced ceramic matrix composites based on silicon carbide (SiC) are being considered as candidate material systems for nuclear fuel cladding in light water reactors. The SiC composite structure is considered due to its assumed exceptional performance under accident scenarios, where its excellent high-temperature strength and slow reaction kinetics with steam and associated mitigated hydrogen production are desirable. The specific structures of interest consist of a monolithic SiC cylinder surrounded by interphase-coated SiC woven fibers in a tubular form and infiltrated with SiC. Additional SiC coatings on the outermost surface of the assembly are also being considered to prevent hydrothermal corrosion of the fibrous structure. The inner monolithic cylinder is expected to provide a hermetic seal to contain fission products under normal conditions. While this approach offers the promise of higher burn-up rates and safer behavior in the case of LOCA events, the reliability of such structures must be demonstrated in advance. Therefore, a probability failure analysis study was performed of such monolithic-composite hybrid structures to determine the feasibility of these design concepts. This analysis will be used to predict the future performance of candidate systems in an effort to determine the feasibility of these design concepts and to make future recommendations regarding materials selection.

Hemrick, James Gordon [ORNL] [ORNL; Lara-Curzio, Edgar [ORNL] [ORNL

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "advanced ceramic composites" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Tailoring of unipolar strain in lead-free piezoelectrics using the ceramic/ceramic composite approach  

SciTech Connect (OSTI)

The electric-field-induced strain response mechanism in a polycrystalline ceramic/ceramic composite of relaxor and ferroelectric materials has been studied using in situ high-energy x-ray diffraction. The addition of ferroelectric phase material in the relaxor matrix has produced a system where a small volume fraction behaves independently of the bulk under an applied electric field. Inter- and intra-grain models of the strain mechanism in the composite material consistent with the diffraction data have been proposed. The results show that such ceramic/ceramic composite microstructure has the potential for tailoring properties of future piezoelectric materials over a wider range than is possible in uniform compositions.

Khansur, Neamul H.; Daniels, John E. [School of Materials Science and Engineering, University of New South Wales, NSW 2052 (Australia); Groh, Claudia; Jo, Wook; Webber, Kyle G. [Institute of Materials Science, Technische Universität Darmstadt, Alarich-Weiss-Straße 2, 64287 Darmstadt (Germany); Reinhard, Christina [Diamond Light Source, Beamline I12 JEEP, Didcot, Oxfordshire OX11 0DE (United Kingdom); Kimpton, Justin A. [The Australian Synchrotron, Clayton, Victoria 3168 (Australia)

2014-03-28T23:59:59.000Z

62

Method for preparing superconductors ceramic composition  

DOE Patents [OSTI]

A process of forming superconductor ceramic oxides from a melt of barium hydroxide and a copper salt selected from copper nitrate and copper acetate.

Akinc, Mufit (Ames, IA); Celikkaya, Ahmet (Ames, IA)

1990-03-06T23:59:59.000Z

63

Directly susceptible, noncarbon metal ceramic composite crucible  

DOE Patents [OSTI]

A sintered metal ceramic crucible suitable for high temperature induction melting of reactive metals without appreciable carbon or silicon contamination of the melt. The crucible comprises a cast matrix of a thermally conductive ceramic material; a perforated metal sleeve, which serves as a susceptor for induction heating of the crucible, embedded within the ceramic cast matrix; and a thermal-shock-absorber barrier interposed between the metal sleeve and the ceramic cast matrix to allow for differential thermal expansions between the matrix and the metal sleeve and to act as a thermal-shock-absorber which moderates the effects of rapid changes of sleeve temperature on the matrix.

Holcombe, Jr., Cressie E. (Farragut, TN); Kiggans, Jr., James O. (Oak Ridge, TN); Morrow, S. Marvin (Kingston, TN); Rexford, Donald (Pattersonville, NY)

1999-01-01T23:59:59.000Z

64

Ceramic composites reinforced with modified silicon carbide whiskers  

DOE Patents [OSTI]

Silicon carbide whisker-reinforced ceramic composites are fabricated in a highly reproducible manner by beneficating the surfaces of the silicon carbide whiskers prior to their usage in the ceramic composites. The silicon carbide whiskers which contain considerable concentrations of surface oxides and other impurities which interact with the ceramic composite material to form a chemical bond are significantly reduced so that only a relatively weak chemical bond is formed between the whisker and the ceramic material. Thus, when the whiskers interact with a crack propagating into the composite the crack is diverted or deflected along the whisker-matrix interface due to the weak chemical bonding so as to deter the crack propagation through the composite. The depletion of the oxygen-containing compounds and other impurities on the whisker surfaces and near surface region is effected by heat treating the whiskers in a suitable oxygen sparaging atmosphere at elevated temperatures. Additionally, a sedimentation technique may be utilized to remove whiskers which suffer structural and physical anomalies which render them undesirable for use in the composite. Also, a layer of carbon may be provided on the surface of the whiskers to further inhibit chemical bonding of the whiskers to the ceramic composite material.

Tiegs, Terry N. (Lenoir City, TN); Lindemer, Terrence B. (Oak Ridge, TN)

1990-01-01T23:59:59.000Z

65

Advanced thermal imaging of composites  

SciTech Connect (OSTI)

Composite materials were studied by Scanning Thermal Conductivity Microscope (STCM) and high speed thermography. The STCM is a qualitative technique which is used to study thermal conductivity variations on a sub-micrometer scale. High speed thermography is a quantitative technique for measuring thermal diffusivity with a variable spatial resolution from centimeters down to less than 25 gm. A relative thermal conductivity contrast map was obtained from a SiC/Si3N4 continuous fiber ceramic composite using the STCM. Temperature changes of a carbon/carbon composite after a heat pulse were captured by an IR camera to generate a thermal diffusivity map of the specimen. Line profiles of the temperature distribution showed significant variations as a result of fiber orientation.

Wang, H.; Dinwiddie, R.B.

1996-06-01T23:59:59.000Z

66

E-Print Network 3.0 - advanced ceramic manufacturing Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

manufacturing Search Powered by Explorit Topic List Advanced Search Sample search results for: advanced ceramic manufacturing Page: << < 1 2 3 4 5 > >> 1 STEVENS INSTITUTE OF...

67

Continuous Fiber Ceramic Composite (CFCC) Program: Gaseous Nitridation  

SciTech Connect (OSTI)

Textron has developed a mature process for the fabrication of continuous fiber ceramic composite (CFCC) tubes for application in the aluminum processing and casting industry. The major milestones in this project are System Composition; Matrix Formulation; Preform Fabrication; Nitridation; Material Characterization; Component Evaluation

R. Suplinskas G. DiBona; W. Grant

2001-10-29T23:59:59.000Z

68

Recent advances in ceramic joining in the context of the needs of CFCC systems  

SciTech Connect (OSTI)

As a part of the DOE Center of Excellence for the Synthesis and Processing of Advanced Materials, a distributed activity coupling twelve national laboratories, research in the joining of ceramics to ceramics and to dissimilar materials is in progress. Included are activities involving reaction bonding, displacement reactions, transient liquid phases, polymeric precursors, and functionally graded joints. A discussion of particular needs associated with the joining of continuous fiber ceramic composites (CFCCs), encountered in the design of structural systems to demonstrate their performance at elevated temperatures, will first be presented. This will be followed by a presentation of initial results obtained in evaluating the above joining technologies in the context of the CFCC joining needs.

Thompson, R.B. [Ames Lab., IA (United States); Jonkouski, J.E. [Department of Energy, Argonne, IL (United States); Rabin, B.H. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

1997-11-01T23:59:59.000Z

69

advanced ceramics advanced: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

. . . . 18 3.4.1 Heat Exchanger - Code description . . . . . . . . . . . . . . . 18 3.4.2 Simulation ResultsADVANCED POWER PLANT MODELING WITH APPLICATIONS TO THE ADVANCED BOILING...

70

E-Print Network 3.0 - advanced ceramic matrix Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Department, Composite Technologies Research Group Collection: Materials Science 14 Thermal and mechanical properties of EPDMPP + thermal shock-resistant ceramic composites...

71

Environmental aging degradation in continuous fiber ceramic composites  

SciTech Connect (OSTI)

The thermal stability of two-continuous fiber ceramic composites (CFCC`s) has been assessed. A Nicalon/CaO-Al{sub 2}O{sub 3}-SiO{sub 2} (CAS) glass-ceramic composite has been subjected to unstressed, oxidation heat treatments between 375 and 1200{degrees}C, after which the material was tested in flexure at room temperature. The static fatigue behavior of a chemical vapor infiltrated (CVI) Nicalon/SiC ceramic matrix composite has been assessed in air, between 425 and 1150{degrees}C, both with and without protective seal coating. Severe property degradation was observed due to oxidation of the graphite fiber/matrix interlayer in both CFCC`s.

Plucknett, K.P.; Lin, H.T.; Braski, D.N.; Becher, P.F.

1995-12-31T23:59:59.000Z

72

Method of making metal matrix composites reinforced with ceramic particulates  

DOE Patents [OSTI]

Composite materials and methods for making such materials are disclosed in which dispersed ceramic particles are at chemical equilibrium with a base metal matrix, thereby permitting such materials to be remelted and subsequently cast or otherwise processed to form net weight parts and other finished (or semi-finished) articles while maintaining the microstructure and mechanical properties (e.g. wear resistance or hardness) of the original composite. The composite materials of the present invention are composed of ceramic particles in a base metal matrix. The ceramics are preferably carbides of titanium, zirconium, tungsten, molybdenum or other refractory metals. The base metal can be iron, nickel, cobalt, chromium or other high temperature metal and alloys thereof. For ferrous matrices, alloys suitable for use as the base metal include cast iron, carbon steels, stainless steels and iron-based superalloys.

Cornie, James A. (North Chelmsford, MA); Kattamis, Theodoulos (Watertown, MA); Chambers, Brent V. (Cambridge, MA); Bond, Bruce E. (Bedford, MA); Varela, Raul H. (Canton, MA)

1989-01-01T23:59:59.000Z

73

Method of making metal matrix composites reinforced with ceramic particulates  

DOE Patents [OSTI]

Composite materials and methods for making such materials are disclosed in which dispersed ceramic particles are at chemical equilibrium with a base metal matrix, thereby permitting such materials to be remelted and subsequently cast or otherwise processed to form net weight parts and other finished (or semi-finished) articles while maintaining the microstructure and mechanical properties (e.g. wear resistance or hardness) of the original composite. The composite materials of the present invention are composed of ceramic particles in a base metal matrix. The ceramics are preferably carbides of titanium, zirconium, tungsten, molybdenum or other refractory metals. The base metal can be iron, nickel, cobalt, chromium or other high temperature metal and alloys thereof. For ferrous matrices, alloys suitable for use as the base metal include cast iron, carbon steels, stainless steels and iron-based superalloys. 2 figs.

Cornie, J.A.; Kattamis, T.; Chambers, B.V.; Bond, B.E.; Varela, R.H.

1989-08-01T23:59:59.000Z

74

Pressureless sintering of whisker-toughened ceramic composites  

DOE Patents [OSTI]

A pressureless sintering method is disclosed for use in the production of whisker-toughened ceramic composites wherein the sintered density of composites containing up to about 20 vol. % SiC whiskers is improved by reducing the average aspect ratio of the whiskers to from about 10 to about 20. Sintering aids further improve the density, permitting the production of composites containing 20 vol. % SiC with sintered densities of 94% or better of theoretical density by a pressureless sintering method.

Tiegs, T.N.

1993-05-04T23:59:59.000Z

75

Pressureless sintering of whiskered-toughened ceramic composites  

DOE Patents [OSTI]

A pressureless sintering method is disclosed for use in the production of whisker-toughened ceramic composites wherein the sintered density of composites containing up to about 20 vol. % SiC whiskers is improved by reducing the average aspect ratio of the whiskers to from about 10 to about 20. Sintering aids further improve the density, permitting the production of composites containing 20 vol. % SiC with sintered densities of 94% or better of theoretical density by a pressureless sintering method.

Tiegs, Terry N. (Lenoir City, TN)

1994-01-01T23:59:59.000Z

76

Pressureless sintering of whisker-toughened ceramic composites  

DOE Patents [OSTI]

A pressureless sintering method is disclosed for use in the production of whisker-toughened ceramic composites wherein the sintered density of composites containing up to about 20 vol. % SiC whiskers is improved by reducing the average aspect ratio of the whiskers to from about 10 to about 20. Sintering aids further improve the density, permitting the production of composites containing 20 vol. % SiC with sintered densities of 94% or better of theoretical density by a pressureless sintering method.

Tiegs, Terry N. (Lenoir City, TN)

1993-01-01T23:59:59.000Z

77

Method of making a continuous ceramic fiber composite hot gas filter  

DOE Patents [OSTI]

A ceramic fiber composite structure particularly suitable for use as a hot gas cleanup ceramic fiber composite filter and method of making same from ceramic composite material has a structure which provides for increased strength and toughness in high temperature environments. The ceramic fiber composite structure or filter is made by a process in which a continuous ceramic fiber is intimately surrounded by discontinuous chopped ceramic fibers during manufacture to produce a ceramic fiber composite preform which is then bonded using various ceramic binders. The ceramic fiber composite preform is then fired to create a bond phase at the fiber contact points. Parameters such as fiber tension, spacing, and the relative proportions of the continuous ceramic fiber and chopped ceramic fibers can be varied as the continuous ceramic fiber and chopped ceramic fiber are simultaneously formed on the porous vacuum mandrel to obtain a desired distribution of the continuous ceramic fiber and the chopped ceramic fiber in the ceramic fiber composite structure or filter.

Hill, Charles A. (Lynchburg, VA); Wagner, Richard A. (Lynchburg, VA); Komoroski, Ronald G. (Lynchburg, VA); Gunter, Greg A. (Lynchburg, VA); Barringer, Eric A. (Lynchburg, VA); Goettler, Richard W. (Lynchburg, VA)

1999-01-01T23:59:59.000Z

78

Dispersion toughened ceramic composites and method for making same  

DOE Patents [OSTI]

Ceramic composites exhibiting increased fracture toughness are produced by the simultaneous codeposition of silicon carbide and titanium disilicide by chemical vapor deposition. A mixture of hydrogen, methyltrichlorosilane and titanium tetrachloride is introduced into a furnace containing a substrate such as graphite or silicon carbide. The thermal decomposition of the methyltrichlorosilane provides a silicon carbide matrix phase and the decomposition of the titanium tetrachloride provides a uniformly dispersed second phase of the intermetallic titanium disilicide within the matrix phase. The fracture toughness of the ceramic composite is in the range of about 6.5 to 7.0 MPa..sqrt..m which represents a significant increase over that of silicon carbide.

Stinton, D.P.; Lackey, W.J.; Lauf, R.J.

1984-09-28T23:59:59.000Z

79

Dispersion toughened ceramic composites and method for making same  

DOE Patents [OSTI]

Ceramic composites exhibiting increased fracture toughness are produced by the simultaneous codeposition of silicon carbide and titanium disilicide by chemical vapor deposition. A mixture of hydrogen, methyltrichlorosilane and titanium tetrachloride is introduced into a furnace containing a substrate such as graphite or silicon carbide. The thermal decomposition of the methyltrichlorosilane provides a silicon carbide matrix phase and the decomposition of the titanium tetrachloride provides a uniformly dispersed second phase of the intermetallic titanium disilicide within the matrix phase. The fracture toughness of the ceramic composite is in the range of about 6.5 to 7.0 MPa.sqroot.m which represents a significant increase over that of silicon carbide.

Stinton, David P. (Knoxville, TN); Lackey, Walter J. (Oak Ridge, TN); Lauf, Robert J. (Oak Ridge, TN)

1986-01-01T23:59:59.000Z

80

Advanced Materials Development Program: Ceramic Technology for Advanced Heat Engines program plan, 1983--1993  

SciTech Connect (OSTI)

The purpose of the Ceramic Technology for Advanced Heat Engines (CTAHE) Project is the development of an industrial technology base capable of providing reliable and cost-effective high temperature ceramic components for application in advanced heat engines. There is a deliberate emphasis on industrial'' in the purpose statement. The project is intended to support the US ceramic and engine industries by providing the needed ceramic materials technology. The heat engine programs have goals of component development and proof-of-concept. The CTAHE Project is aimed at developing generic basic ceramic technology and does not involve specific engine designs and components. The materials research and development efforts in the CTAHE Project are focused on the needs and general requirements of the advanced gas turbine and low heat rejection diesel engines. The CTAHE Project supports the DOE Office of Transportation Systems' heat engine programs, Advanced Turbine Technology Applications (ATTAP) and Heavy Duty Transport (HDT) by providing the basic technology required for development of reliable and cost-effective ceramic components. The heat engine programs provide the iterative component design, fabrication, and test development logic. 103 refs., 18 figs., 11 tabs.

Not Available

1990-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "advanced ceramic composites" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

High temperature ceramic composition for hydrogen retention  

DOE Patents [OSTI]

A ceramic coating for H retention in fuel elements is described. The coating has relatively low thermal neutron cross section, is not readily reduced by H at 1500 deg F, is adherent to the fuel element base metal, and is stable at reactor operating temperatures. (JRD)

Webb, R.W.

1974-01-01T23:59:59.000Z

82

Development of ASTM standards in support of advanced ceramics -- continuing efforts  

SciTech Connect (OSTI)

An update is presented of the activities of the American Society for Testing and Materials (ASTM) Committee C-28 on Advanced Ceramics. Since its inception in 1986, this committee, which has five standard producing subcommittees, has written and published over 32 consensus standards. These standards are concerned with mechanical testing of monolithic and composite ceramics, nondestructive examination, statistical analysis and design, powder characterization, quantitative microscopy, fractography, and terminology. These standards ensure optimum material behavior with physical and mechanical property reproducibility, component reliability, and well-defined methods of data treatment and material analysis for both monolithic and composite materials. Committee C-28 continues to sponsor technical symposia and to cooperate in the development of international standards. An update of recent and current activities as well as possible new areas of standardization work will be presented.

Brinkman, C.R.

1998-02-01T23:59:59.000Z

83

Characterizing Three-Dimensional Textile Ceramic Composites Using Synchrotron X-Ray Micro-Computed-Tomography  

E-Print Network [OSTI]

, Thousand Oaks, CA 91360 Three-dimensional (3-D) images of two ceramic-matrix textile composites were studied represent a new class of integrally woven ceramic matrix composites for high-temperature appliCharacterizing Three-Dimensional Textile Ceramic Composites Using Synchrotron X-Ray Micro

Ritchie, Robert

84

Freeforming of Ceramics and Composites from Colloidal Slurries  

SciTech Connect (OSTI)

This report is a summary of the work completed for an LDRD project. The objective of the project was to develop a solid freeform fabrication technique for ceramics and composites from fine particle slurries. The work was successful and resulted in the demonstration of a manufacturing technique called robocasting. Some ceramic components may pow be fabricated without the use of molds or tooling by dispensing colloidal suspensions through an orifice and stacking two-dimensional layers into three-dimensional shapes. Any conceivable two-dimensional pattern may be ''written'' layer by layer into a three-dimensional shape. Development of the robocasting technique required the materials expertise for fabrication and theological control of very highly concentrated fine particle slurries, and development of robotics for process control and optimization. Several ceramic materials have been manufactured and characterized. Development of techniques for robocasting multiple materials simultaneously have also been developed to build parts with unique structures or graded compositions.

CESARANO III,JOSEPH; DENHAM,HUGH B.; STUECKER,JOHN N.; BAER,THOMAS A.; GRIFFITH,MICHELLE L.

1999-12-01T23:59:59.000Z

85

Continuous fiber ceramic composites. Phase II - Final report  

SciTech Connect (OSTI)

This report documents Atlantic Research Corporation's (ARC) Phase 11 effort on the Department of Energy's (DOE) Continuous Fiber Ceramic Composite (CFCC) program. This project is supported by the DOE cooperative agreement DE-FCO2-92CE40998. Such DOE support does not constitute an endorsement of the views expressed in this report. ARC'S CFCC Phase II effort began during October 1993 and was suspended in March of 1997 when, for business considerations, ARC closed the Amercom operation. This report covers progress from Phase II program inception through Amercom closure. ARC'S Phase II effort built upon the results of the Phase I Applications Assessment and Process Engineering developments to produce CFCC test components for end-user evaluation. Initially, the Phase 11 effort planned to develop and produce three CFCC components: CFCC compression rings for stationary diesel engines, CFCC hot gas fans for industrial furnace applications, and CFCC hot gas filters for current and advanced coal fired power cycles. As the program progressed, the development effort for the diesel engine piston rings was suspended. This decision was based on technical issues, cost factors and reduced program funding; the status of CFCC diesel engine piston ring development will be discussed in detail in section 2.2.1.

Bird, James

1997-10-31T23:59:59.000Z

86

KNN–NTK composite lead-free piezoelectric ceramic  

SciTech Connect (OSTI)

A (K,Na)NbO{sub 3}-based lead-free piezoelectric ceramic was successfully densified. It exhibited an enhanced electromechanical coupling factor of k{sub p}?=?0.52, a piezoelectric constant d{sub 33}?=?252 pC/N, and a frequency constant N{sub p}?=?3170?Hz m because of the incorporation of an elaborate secondary phase composed primarily of KTiNbO{sub 5}. The ceramic's nominal composition was 0.92K{sub 0.42}Na{sub 0.44}Ca{sub 0.04}Li{sub 0.02}Nb{sub 0.85}O{sub 3}–0.047K{sub 0.85}Ti{sub 0.85}Nb{sub 1.15}O{sub 5}–0.023BaZrO{sub 3} –0.0017Co{sub 3}O{sub 4}–0.002Fe{sub 2}O{sub 3}–0.005ZnO, abbreviated herein as KNN–NTK composite. The KNN–NTK ceramic exhibited a dense microstructure with few microvoids which significantly degraded its piezoelectric properties. Elemental maps recorded using transmission electron microscopy with energy-dispersive X-ray spectroscopy (TEM–EDS) revealed regions of high concentrations of Co and Zn inside the NTK phase. In addition, X-ray diffraction patterns confirmed that a small portion of the NTK phase was converted into K{sub 2}(Ti,Nb,Co,Zn){sub 6}O{sub 13} or CoZnTiO{sub 4} by a possible reaction between Co and Zn solutes and the NTK phase during a programmed sintering schedule. TEM studies also clarified a distortion around the KNN/NTK interfaces. Such an NTK phase filled voids between KNN particles, resulting in an improved chemical stability of the KNN ceramic. The manufacturing process was subsequently scaled to 100?kg per batch for granulated ceramic powder using a spray-drying technique. The properties of the KNN–NTK composite ceramic produced using the scaled-up method were confirmed to be identical to those of the ceramic prepared by conventional solid-state reaction sintering. Consequently, slight changes in the NTK phase composition and the distortion around the KNN/NTK interfaces affected the KNN–NTK composite ceramic's piezoelectric characteristics.

Matsuoka, T., E-mail: ta-matsuoka@mg.ngkntk.co.jp; Kozuka, H.; Kitamura, K.; Yamada, H.; Kurahashi, T.; Yamazaki, M.; Ohbayashi, K. [NGK SPARK PLUG Co., Ltd., 2808 Iwasaki, Komaki, Aichi 485-8510 (Japan)

2014-10-21T23:59:59.000Z

87

Ceramic Matrix Composites | GE Global Research  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed New Substation SitesStanding Friedel Waves,TheoryParliament'v0, 12/9/14Ceramic Matrix

88

Method for producing ceramic composition having low friction coefficient at high operating temperatures  

DOE Patents [OSTI]

A method for producing a stable ceramic composition having a surface with a low friction coefficient and high wear resistance at high operating temperatures. A first deposition of a thin film of a metal ion is made upon the surface of the ceramic composition and then a first ion implantation of at least a portion of the metal ion is made into the near surface region of the composition. The implantation mixes the metal ion and the ceramic composition to form a near surface composite. The near surface composite is then oxidized sufficiently at high oxidizing temperatures to form an oxide gradient layer in the surface of the ceramic composition.

Lankford, Jr., James (San Antonio, TX)

1988-01-01T23:59:59.000Z

89

Ceramic composites: Roles of fiber and interface  

SciTech Connect (OSTI)

Results are presented that elucidate (a) the effects of fiber coating on retained fiber strength and mechanical properties of Nicalon-fiber-reinforced SiC matrix composites, and (b) the role of residual stresses in the interfacial bond strength of SiC-fiber-reinforced reaction-bonded Si{sub 3}N{sub 4} matrix composites. For Nicalon-fiber-reinforced SiC matrix composites that were fractured in a flexural mode, retained in-situ fiber strength, ultimate strength, and work-of-fracture (WOF) of the composites increased with increasing thickness of the fiber coating and reached maximum values at a coating thickness of {approx} 0.3 {micro}m. A direct correlation between the variation of in-situ fiber strength and the variation of ultimate strength and WOF of the composites clearly indicates the critical role of the retained in-situ strength of reinforcing fibers in composites. Fiber pushout tests performed on SiC-fiber-reinforced reaction-bonded Si{sub 3}N{sub 4} matrix composites indicate that both debonding and frictional shear stresses decreased with increasing fiber content. These variations are consistent with the variation of residual radial stress on fibers, as measured by neutron diffraction, i.e., residual stresses decreased with increasing fiber content. Because fracture behavior is strongly controlled by interfacial bond strength, which is proportional to the residual radial stress, appropriate control of residual stress is critical in the design of composites with desired fracture properties.

Singh, J.P.; Singh, D. [Argonne National Lab., IL (United States). Energy Technology Div.

1997-09-01T23:59:59.000Z

90

E-Print Network 3.0 - advanced ceramic reactors Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

& Advanced Separations Technology ITM Syngas... ) Fossil-Based Hydrogen Production Praxair Praxair SNL TIAX Integrated Ceramic Membrane ... Source: DOE Office of Energy...

91

Pressureless sintering of whiskered-toughened ceramic composites  

DOE Patents [OSTI]

A pressureless sintering method is disclosed for use in the production of whisker-toughened ceramic composites wherein the sintered density of composites containing up to about 20 vol. % SiC whiskers is improved by reducing the average aspect ratio of the whiskers to from about 10 to about 20. Sintering aids further improve the density, permitting the production of composites containing 20 vol. % SiC with sintered densities of 94% or better of theoretical density by a pressureless sintering method. 6 figures.

Tiegs, T.N.

1994-12-27T23:59:59.000Z

92

A modified test for measuring the interlaminar tensile strength of fiber-reinforced ceramic composites  

E-Print Network [OSTI]

2007 Elsevier Ltd. All rights reserved. Keywords: A. Ceramic matrix composites; B. Strength; C. Finite challenges confronting the utilization of ceramic matrix composites (CMCs) within high temper- ature systemsA modified test for measuring the interlaminar tensile strength of fiber-reinforced ceramic

Zok, Frank

93

CERAMIC COMPOSITES FOR NEAR TERM REACTOR APPLICATION  

SciTech Connect (OSTI)

Currently, two composites types are being developed for incore application: carbon fiber carbon composite (CFC), and silicon carbide fiber composite (SiC/SiC.) Irradiation effects studies have been carried out over the past few decades yielding radiation-tolerant CFC's and a composite of SiC/SiC with no apparent degradation in mechanical properties to very high neutron exposure. While CFC's can be engineered with significantly higher thermal conductivity, and a slight advantage in manufacturability than SiC/SiC, they do have a neutron irradiation-limited lifetime. The SiC composite, while possessing lower thermal conductivity (especially following irradiation), appears to have mechanical properties insensitive to irradiation. Both materials are currently being produced to sizes much larger than that considered for nuclear application. In addition to materials aspects, results of programs focusing on practical aspects of deploying composites for near-term reactors will be discussed. In particular, significant progress has been made in the fabrication, testing, and qualification of composite gas-cooled reactor control rod sheaths and the ASTM standardization required for eventual qualification.

Snead, Lance Lewis [ORNL; Burchell, Timothy D [ORNL; Windes, Will [Idaho National Laboratory (INL); Katoh, Yutai [ORNL

2010-01-01T23:59:59.000Z

94

INFRARED IMAGING OF CARBON AND CERAMIC COMPOSITES: DATA REPRODUCIBILITY  

SciTech Connect (OSTI)

Infrared NDE techniques have proven to be superior for imaging of flaws in ceramic matrix composites (CMC) and carbon silicon carbide composites (C/SiC). Not only can one obtain accurate depth gauging of flaws such as delaminations and layered porosity in complex-shaped components such as airfoils and other aeronautical components, but also excellent reproducibility of image data is obtainable using the STTOF (Synthetic Thermal Time-of-Flight) methodology. The imaging of large complex shapes is fast and reliable. This methodology as applied to large C/SiC flight components at the NASA Dryden Flight Research Center will be described.

Knight, B.; Howard, D. R.; Ringermacher, H. I. [GE Global Research Center, Niskayuna, NY 12309 (United States); Hudson, L. D. [NASA Dryden Flight Research Center, Edwards AFB, CA (United States)

2010-02-22T23:59:59.000Z

95

Approach to inherently stable interfaces for ceramic matrix composites  

SciTech Connect (OSTI)

Virtually all ceramic matrix composites require and interface coating between the fibers and matrix to achieve the desired mechanical performance. To date, the most effective interface materials for non- oxide matrix composites have been carbon and boron nitride. They are, however, susceptible to oxidation at elevated temperatures, and thus under many envisioned operating environments they will fail, possibly allowing oxidation of the fibers as well, adversely affecting mechanical behavior. Current efforts are directed toward developing stable interface coating, which include oxides and silicon carbide with appropriate thermomechanical properties.

Besmann, T.M.; Kupp, E.R.; Stinton, D.P. [Oak Ridge National Lab., TN (United States); Shanmugham, S. [Tennessee Univ., Knoxville, TN (United States). Dept. of Materials Science and Engineering

1996-09-01T23:59:59.000Z

96

Ceramic compositional analysis in archaeological perspective  

SciTech Connect (OSTI)

The primary significance of compositional analysis in archaeology lies on the spatial dimension, in distinguishing products made by locally or regionally-based groups. If compositional analysis is to be carried beyond the descriptive recording of similarities and differences, the resource procurement zone (and its geographical relationship to inferred places of manufacture) is a basic operational concept (Rands and Bishop 1980). A zonal concept is clearly indicated in the case of pottery, which frequently is derived from raw materials, clay and temper, that do not necessarily coincide in their place of procurement. Moreover, depending on geomorphological and geochemical variables, these materials may show considerable homogeneity over a fairly extended area. On the other hand, unless there is strong, selective patterning in the exploitation of resources, great heterogeneity within a restricted region may result in fragmented procurement zones that are difficult to equate with the products of specific manufacturing centers. Under favorable circumstances, however, it appears that methods of compositional analysis are approaching the point at which microzones of limited geographical extent can be recognized and assigned heuristically useful boundaries.

Bishop, R.L.; Rands, R.L.; Holley, G.R.

1980-01-01T23:59:59.000Z

97

Study of Thermo-Electro-Mechnical Coupling in Functionally Graded Metal-Ceramic Composites  

E-Print Network [OSTI]

Piezoelectric actuators have been developed in various forms ranging from discrete layered composites to functionally graded composites. These composite actuators are usually made up of differentially poled piezoelectric ceramics. This study...

Doshi, Sukanya 1988-

2012-12-10T23:59:59.000Z

98

Methodologies for the thermomechanical characterization of continuous-fiber ceramic matrix composites: A review of test methods  

SciTech Connect (OSTI)

Requirements for thermomechanical characterization of ceramic matrix composite materials are reviewed. Feasibility of adapting existent room temperature test methods for polymer and metal matrix composites to test ceramic matrix composites at room and elevated temperatures is investigated.

Lara-Curzio, E.; Ferber, M.K. [Oak Ridge National Lab., TN (United States); Jenkins, M.G. [Washington Univ., Seattle, WA (United States). Dept. of Mechanical Engineering

1994-05-01T23:59:59.000Z

99

Exposure of Ceramics and Ceramic Matrix Composites in Simulated and Actual Combustor Environments  

SciTech Connect (OSTI)

A high-temperature, high-pressure, tube furnace has been used to evaluate the long term stability of different monolithic ceramic and ceramic matrix composite materials in a simulated combustor environment. All of the tests have been run at 150 psia, 1204 degrees C, and 15% steam in incremental 500 h runs. The major advantage of this system is the high sample throughput; >20 samples can be exposed in each tube at the same time under similar exposure conditions. Microstructural evaluations of the samples were conducted after each 500 h exposure to characterize the extent of surface damage, to calculate surface recession rates, and to determine degradation mechanisms for the different materials. The validity of this exposure rig for simulating real combustor environments was established by comparing materials exposed in the test rig and combustor liner materials exposed for similar times in an actual gas turbine combustor under commercial operating conditions.

Brentnall, W.D.; Ferber, M.K.; Keiser, j.R.; Miriyala, N.; More, K.L.; Price, J.R.; Tortorelli, P.F.; Walker, L.R.

1999-06-07T23:59:59.000Z

100

Oxidation-resistant interfacial coatings for continuous fiber ceramic composites  

SciTech Connect (OSTI)

Developing an oxidation-resistant interfacial coating for continuous fiber ceramic composites (CFCCs) continues to be a major challenge. CFCCs` mechanical behavior are influenced by the interfacial bonding characteristics between the fiber and the matrix. Finite element modeling studies suggest that a low-modulus interfacial coating material will be effective in reducing the residual thermal stresses that are generated upon cooling from processing temperatures. Nicalon/SiC composites with carbon, alumina and mullite interfacial coatings were fabricated with the SiC matrix deposited using a forced-flow chemical vapor infiltration process. Composites with mullite interfacial coatings exhibited considerable fiber pull-out even after oxidation and have potential as a composite system.

Shanmugham, S.; Liaw, P.K. [Tennessee Univ., Knoxville, TN (United States); Stinton, D.P.; Bleier, A.; Besmann, T.M.; Lara-Curzio, E. [Oak Ridge National Lab., TN (United States); Rebillat, F. [LCTS, Pessac (France)

1995-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "advanced ceramic composites" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

"Ceramics and high-temperature composites, silicides" Oxidation of Stainless Steel Powder  

E-Print Network [OSTI]

: Powder, stainless steel, oxidation INTRODUCTION Ceramic matrix composites dispersed with metal particles"Ceramics and high-temperature composites, silicides" CHTC9 Oxidation of Stainless Steel Powder. To understand the corrosion behavior of a model 304L(p)-ZrO2(s) composite, a 304L stainless steel powder has

Paris-Sud XI, Université de

102

Oxidation-resistant interfacial coatings for fiber-reinforced ceramic composites  

SciTech Connect (OSTI)

A ceramic-matrix composite having a multilayered interfacial coating adapted to protect the reinforcing fibers from long-term oxidation, while allowing these to bridge the wake of advancing cracks in the matrix, is provided by selectively mismatching materials within adjacent layers of the interfacial coating, the materials having different coefficients of thermal expansion so that a low toughness interface region is created to promote crack deflection either within an interior layer of the mismatched interfacial coating or between adjacent layers of the mismatched interfacial coating.

Lara-Curzio, Edgar; More, Karren L.; Lee, Woo Y.

1999-04-22T23:59:59.000Z

103

Thermal and mechanical properties of EPDM/PP + thermal shock-resistant ceramic composites  

E-Print Network [OSTI]

the polymer matrix. The brittleness, B, decreases upon surface modification of the ceramic. The highest valueThermal and mechanical properties of EPDM/PP + thermal shock-resistant ceramic composites Witold-scale ceramic powder. To overcome the difficulty of particles dispersion and adhe- sion, the filler was modified

North Texas, University of

104

High-temperature corrosion of ceramic-ceramic composites in a waste incinerator environment  

SciTech Connect (OSTI)

Three types of ceramic composite were exposed to flue gases of a hazardous waste incinerator to assess their corrosion behavior. One composite consisted of continuously wound filaments of Al{sub 2}0{sub 3}-23 wt % ZrO{sub 2} in an alumina matrix. This composite was tested, both uncoated and coated, with zirconia on the outer surface. The second composite type consisted of the same fiber but in a zirconia matrix The third composite consisted of an alumina matrix strengthened with silicon carbide particles. Tubes of these materials were exposed in the waste incinerator at about 900{degrees}C for times up to six months. Two principal results of exposure were revealed by optical microscopy and electron microprobe examinations: flue gas constituents either penetrated the uncoated alumina matrix of the filament-wound composite, apparently through porosity in the matrix, or deposited on the surfaces of the other composite types where reaction and bonding occurred. Neither event caused significant microstructural degradation although thereaction in the composite with a zirconia matrix suggests that degradation could be a problem under more severe conditions. Apparently, the concentration of penetrating species was too small to form a significant amount of new compounds that could cause degradation within the alumina matrix of the filament-wound composite, and the temperature was too low for the deposits on the surface of the other two types of composites to react significantly with the materials during the longest exposure of 6 months. The zirconia coating on the alumina matrix composite was not adherent enough to permit an assessment of its effect.

Keiser, J.R.; Federer, J.I.; Henson, T.J. [Oak Ridge National Lab., TN (United States); Hindman, D.L. [Babcock and Wilcox Co., Lynchburg, VA (United States)

1993-01-01T23:59:59.000Z

105

Melt Infiltrated Ceramic Composites (Hipercomp) for Gas Turbine Engine Applications  

SciTech Connect (OSTI)

This report covers work performed under the Continuous Fiber Ceramic Composites (CFCC) program by GE Global Research and its partners from 1994 through 2005. The processing of prepreg-derived, melt infiltrated (MI) composite systems based on monofilament and multifilament tow SiC fibers is described. Extensive mechanical and environmental exposure characterizations were performed on these systems, as well as on competing Ceramic Matrix Composite (CMC) systems. Although current monofilament SiC fibers have inherent oxidative stability limitations due to their carbon surface coatings, the MI CMC system based on multifilament tow (Hi-Nicalon ) proved to have excellent mechanical, thermal and time-dependent properties. The materials database generated from the material testing was used to design turbine hot gas path components, namely the shroud and combustor liner, utilizing the CMC materials. The feasibility of using such MI CMC materials in gas turbine engines was demonstrated via combustion rig testing of turbine shrouds and combustor liners, and through field engine tests of shrouds in a 2MW engine for >1000 hours. A unique combustion test facility was also developed that allowed coupons of the CMC materials to be exposed to high-pressure, high-velocity combustion gas environments for times up to {approx}4000 hours.

Gregory Corman; Krishan Luthra

2005-09-30T23:59:59.000Z

106

advanced metallic ceramic: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

j and the magnetic field H in Bi2Sr2CaCu2O8 x ceramics. We provided in high-Tc superconduct- ing granular ceramics remain an intriguing subject of inten- sive investigations...

107

advanced structural ceramics: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

j and the magnetic field H in Bi2Sr2CaCu2O8 x ceramics. We provided in high-Tc superconduct- ing granular ceramics remain an intriguing subject of inten- sive investigations...

108

Bonded carbon or ceramic fiber composite filter vent for radioactive waste  

DOE Patents [OSTI]

Carbon bonded carbon fiber composites as well as ceramic or carbon bonded ceramic fiber composites are very useful as filters which can separate particulate matter from gas streams entraining the same. These filters have particular application to the filtering of radioactive particles, e.g., they can act as vents for containers of radioactive waste material.

Brassell, Gilbert W. (13237 W. 8th Ave., Golden, CO 80401); Brugger, Ronald P. (Lafayette, CO)

1985-02-19T23:59:59.000Z

109

MODELING AND ADAPTIVE NUMERICAL TECHNIQUES FOR OXI-DATION OF CERAMIC COMPOSITES  

E-Print Network [OSTI]

. INTRODUCTION Oxidation shortens the life of ceramic matrix composites by, e.g., chang- ing the elasticMODELING AND ADAPTIVE NUMERICAL TECHNIQUES FOR OXI- DATION OF CERAMIC COMPOSITES S. Adjerid, M. Ai of thermal or other loading may expose the matrix and bers to hostile envi- ronments. We present a model

Adjerid, Slimane

110

Computational modeling of damage evolution in unidirectional fiber reinforced ceramic matrix composites  

E-Print Network [OSTI]

Computational modeling of damage evolution in unidirectional fiber reinforced ceramic matrix mechanical re- sponse of a ceramic matrix composite is simulated by a numerical model for a ®ber-matrix unit evolution in brittle matrix composites was developed. This modeling is based on an axisymmetric unit cell

Ortiz, Michael

111

Ferroelectric and dielectric properties of ferrite-ferroelectric ceramic composites  

SciTech Connect (OSTI)

Particulate composites of ferrite and ferroelectric phases with xNiFe{sub 2}O{sub 4} (NF) and (1 - x)Pb{sub 0.988}(Zr{sub 0.52}Ti{sub 0.48}){sub 0.976}Nb{sub 0.024}O{sub 3} (where x = 2, 10, 20, 30, 50, 70, and 100 wt. %) were prepared in situ by sol-gel method. The presence of a diphase composition was confirmed by X-ray diffraction while the microstructure of the composites was studied by scanning electron microscopy revealing a good mixing of the two phases and a good densification of the bulk ceramics. The dielectric permittivity shows usual dielectric dispersion behavior with increasing frequency due to Maxwell-Wagner interfacial polarization. AC conductivity measurements made in frequency range 1 Hz-1 MHz suggest that the conduction process is due to mixed polaron hopping. The effect of NF phase concentration on the P-E and M-H hysteresis behavior and dielectric properties of the composites was investigated. At low NF concentration a sharp ferro-paraelectric transition peak can be observed at around 360 Degree-Sign C while for higher NF concentrations a trend to a diffuse phase transition occurs. All the composite samples exhibit typical ferromagnetic hysteresis loops, indicating the presence of ordered magnetic structure.

Elena Ciomaga, Cristina; Maria Neagu, Alexandra; Valentin Pop, Mihai; Mitoseriu, Liliana [Faculty of Physics, 'Al. I. Cuza' University of Iasi 700506, Iasi (Romania); Airimioaei, Mirela [Faculty of Chemistry, 'Al. I. Cuza' University of Iasi 700506, Iasi, Romania and Dept. Chemistry and Process Engineering, University of Genoa, P-le Kennedy no. 1, I-16129, Genoa (Italy); Tascu, Sorin [RAMTECH Faculty of Physics, 'Al. I. Cuza' University of Iasi 700506 (Romania); Schileo, Giorgio [Christian Doppler Laboratory for Advanced Ferroic Oxides, Sheffield Hallam University, Howard Street, Sheffield S1 1WB (United Kingdom); Galassi, Carmen [CNR-ISTEC, Via Granarolo no. 64, I-48018 Faenza (Italy)

2013-02-21T23:59:59.000Z

112

"A New Class of Creep Resistant Oxide/Oxide Ceramic Matrix Composites"  

SciTech Connect (OSTI)

Despite recent progress in the development of SiC-SiC ceramic matrix composites (CMCs), their application in industrial gas turbines for distributed energy (DE) systems has been limited. The poor oxidation resistance of the non-oxide ceramics warrants the use of envrionmental barrier coatings (EBCs), which in turn lead to issues pertaining to life expectancy of the coatings. On the other hand, oxide/oxide CMCs are potential replacements, but their use has been limited until now due to the poor creep resistance at high temperatures, particularly above 1200 oC: the lack of a creep resistant matrix has been a major limiting factor. Using yttrium aluminum garnet (YAG) as the matrix material system, we have advanced the state-of-the-art in oxide/oxide CMCs by introducing innovations in both the structure and composition of the matrix material, thereby leading to high temperature matrix creep properties not achieved until now. An array of YAG-based powders with a unique set of particle characteristics were produced in-house and sintered to full density and compressive creep data was obtained. Aided in part by the composition and the microstructure, the creep rates were found to be two orders of magnitude smaller than the most creep resistant oxide fiber available commercially. Even after accounting for porosity and a smaller matrix grain size in a practical CMC component, the YAG-based matrix material was found to creep slower than the most creep resistant oxide fiber available commercially.

Dr. Mohit Jain, Dr. Ganesh Skandan, Prof. Roger Cannon, Rutgers University

2007-03-30T23:59:59.000Z

113

Life prediction methodology for ceramic components of advanced heat engines. Phase 1: Volume 1, Final report  

SciTech Connect (OSTI)

Emphasis of this program is to develop and demonstrate ceramics life prediction methods, including fast fracture, stress rupture, creep, oxidation, and nondestructive evaluation. Significant advancements were made in these methods and their predictive capabilities successfully demonstrated.

Cuccio, J.C.; Brehm, P.; Fang, H.T. [Allied-Signal Aerospace Co., Phoenix, AZ (United States). Garrett Engine Div.] [and others

1995-03-01T23:59:59.000Z

114

High-Frequency Fatigue Behavior of Woven-Fiber-Fabric-Reinforced Polymer-Derived Ceramic-Matrix Composites  

E-Print Network [OSTI]

High-Frequency Fatigue Behavior of Woven-Fiber-Fabric-Reinforced Polymer-Derived Ceramic-Matrix heat exchangers, continuous-fiber-reinforced ceramic- matrix composites (CFCMCs) will encounter cyclic glass-matrix composite showed that, unlike monolithic ceramics, fatigue life of this composite decreased

Barber, James R.

115

Advanced Materials and Processing of Composites for High Volume...  

Broader source: Energy.gov (indexed) [DOE]

Advanced Materials and Processing of Composites for High Volume Applications Advanced Materials and Processing of Composites for High Volume Applications 2011 DOE Hydrogen and Fuel...

116

Innovative grinding wheel design for cost-effective machining of advanced ceramics  

SciTech Connect (OSTI)

This Final Report covers the Phase II Innovative Grinding Wheel (IGW) program in which Norton Company successfully developed a novel grinding wheel for cost-effective cylindrical grinding of advanced ceramics. In 1995, Norton Company successfully completed the 16-month Phase I technical effort to define requirements, design, develop, and evaluate a next-generation grinding wheel for cost-effective cylindrical grinding of advanced ceramics using small prototype wheels. The Phase II program was initiated to scale-up the new superabrasive wheel specification to larger diameters, 305-mm to 406-mm, required for most production grinding of cylindrical ceramic parts, and to perform in-house and independent validation grinding tests.

Licht, R.H.; Kuo, P.; Liu, S.; Murphy, D.; Picone, J.W.; Ramanath, S.

2000-05-01T23:59:59.000Z

117

Modeling of flexural behavior of continuous fiber ceramic composites  

SciTech Connect (OSTI)

The flexural behavior of 2-D continuous fiber-reinforced ceramic composites (CFCC) is modeled using a finite element analysis. This model extends the analysis of Steif and Trojnacki to account for the effect of the weak interlaminar properties of most 2-D CFCCs on their flexural behavior. The model predictions confirm the findings of Steif and Trojnacki that the slope of the slow decaying tail which arises from fiber pull-out and that would be observed experimentally in the tensile stress-strain curve when the test is conducted under displacement-controlled loading conditions is the most influential parameter in the difference between tensile and {open_quotes}flexural strengths{close_quotes}. The model predictions are used to explain the difference between tensile and {open_quotes}flexural strengths{close_quotes} and to assess the effect of specimen geometry (e.g. span and specimen thickness) on the bending behavior of 2-D CFCCs.

Raghuraman, S.; Lara-Curzio, E.; Ferber, M.K. [Oak Ridge National Lab., TN (United States)

1996-12-31T23:59:59.000Z

118

Continuous fiber ceramic composites for energy related applications. Final report  

SciTech Connect (OSTI)

The US Department of Energy has established the Continuous Fiber Ceramic Composites (CFCC) program to develop technology for the manufacture of CFCC`s for use in industrial applications where a reduction in energy usage or emissions could be realized. As part of this program, the Dow Chemical Company explored the manufacture of a fiber reinforced/self reinforced silicon nitride for use in industrial chemical processing. In Dow`s program, CFCC manufacturing technology was developed around traditional, cost effective, tape casting routes. Formulations were developed and coupled with unique processing procedures which enabled the manufacture of tubular green laminates of the dimension needed for the application. An evaluation of the effect of various fibers and fiber coatings on the properties of a fiber reinforced composites was also conducted. Results indicated that fiber coatings could provide composites exhibiting non-catastrophic failure and substantially improved toughness. However, an evaluation of these materials in industrial process environments showed that the material system chosen by Dow did not provide the required performance improvements to make replacement of current metallic components with CFCC components economically viable.

NONE

1998-04-07T23:59:59.000Z

119

Silicon carbide whisker reinforced ceramic composites and method for making same  

DOE Patents [OSTI]

The present invention is directed to the fabrication of ceramic composites which possess improved mechanical properties especially increased fracture toughness. In the formation of these ceramic composites, the single crystal SiC whiskers are mixed with fine ceramic powders of a ceramic material such as Al.sub.2 O.sub.3, mullite, or B.sub.4 C. The mixtures which contain a homogeneous disperson of the SiC whiskers are hot pressed at pressures in a range of about 28 to 70 MPa and temperatures in the range of about 1600.degree. to 1950.degree. C. with pressing times varying from about 0.075 to 2.5 hours. The resulting ceramic composites show an increase in fracture toughness of up to about 9 MPa.m.sup.1/2 which represents as much as a two-fold increase over that of the matrix material.

Wei, George C.

1993-11-16T23:59:59.000Z

120

Silicon carbide whisker reinforced ceramic composites and method for making same  

DOE Patents [OSTI]

The present invention is directed to the fabrication of ceramic composites which possess improved mechanical properties especially increased fracture toughness. In the formation of these ceramic composites, the single crystal SiC whiskers are mixed with fine ceramic powders of a ceramic material such as Al{sub 2}O{sub 3}, mullite, or B{sub 4}C. The mixtures which contain a homogeneous dispersion of the SiC whiskers are hot pressed at pressures in a range of about 28 to 70 MPa and temperatures in the range of about 1,600 to 1,950 C with pressing times varying from about 0.75 to 2.5 hours. The resulting ceramic composites show an increase in fracture toughness which represents as much as a two-fold increase over that of the matrix material.

Wei, G.C.

1989-01-24T23:59:59.000Z

Note: This page contains sample records for the topic "advanced ceramic composites" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Silicon carbide whisker reinforced ceramic composites and method for making same  

DOE Patents [OSTI]

The present invention is directed to the fabrication of ceramic composites which possess improved mechanical properties especially increased fracture toughness. In the formation of these ceramic composites, the single crystal SiC whiskers are mixed with fine ceramic powders of a ceramic material such as Al.sub.2 O.sub.3, mullite, or B.sub.4 C. The mixtures which contain a homogeneous dispersion of the SiC whiskers are hot pressed at pressures in a range of about 28 to 70 MPa and temperatures in the range of about 1600.degree. to 1950.degree. C. with pressing times varying from about 0.75 to 2.5 hours. The resulting ceramic composites show an increase in fracture toughness of up to about 9 MPa.m.sup.1/2 which represents as much as a two-fold increase over that of the matrix material.

Wei, George C. (Oak Ridge, TN)

1985-01-01T23:59:59.000Z

122

Silicon carbide whisker reinforced ceramic composites and method for making same  

DOE Patents [OSTI]

The present invention is directed to the fabrication of ceramic composites which possess improved mechanical properties especially increased fracture toughness. In the formation of these ceramic composites, the single crystal SiC whiskers are mixed with fine ceramic powders of a ceramic material such as Al.sub.2 O.sub.3, mullite, or B.sub.4 C. The mixtures which contain a homogeneous disperson of the SiC whiskers are hot pressed at pressures in a range of about 28 to 70 MPa and temperatures in the range of about 1600.degree. to 1950.degree. C. with pressing times varying from about 0.075 to 2.5 hours. The resulting ceramic composites show an increase in fracture toughness of up to about 9 MPa.m.sup.1/2 which represents as much as a two-fold increase over that of the matrix material.

Wei, George C. (Oak Ridge, TN)

1993-01-01T23:59:59.000Z

123

Silicon carbide whisker reinforced ceramic composites and method for making same  

DOE Patents [OSTI]

The present invention is directed to the fabrication of ceramic composites which possess improved mechanical properties especially increased fracture toughness. In the formation of these ceramic composites, the single crystal SiC whiskers are mixed with fine ceramic powders of a ceramic material such as Al.sub.2 O.sub.3, mullite, or B.sub.4 C. The mixtures which contain a homogeneous disperson of the SiC whiskers are hot pressed at pressures in a range of about 28 to 70 MPa and temperatures in the range of about 1600.degree. to 1950.degree. C. with pressing times varying from about 0.75 to 2.5 hours. The resulting ceramic composites show an increase in fracture toughness of up to about 9 MP.am.sup.1/2 which represents as much as a two-fold increase over that of the matrix material.

Wei, George C. [Oak Ridge, TN

1989-01-24T23:59:59.000Z

124

Thermal imaging measurement and correlation of thermal diffusivity in continuous fiber ceramic composites  

SciTech Connect (OSTI)

Continuous fiber ceramic matrix composites (CFCCs) are currently being developed for a variety of high-temperature applications, including use in advanced heat engines. For such composites, knowledge of porosity distribution and presence of defects is important for optimizing mechanical and thermal behavior of the components. The assessment of porosity and its distribution is also necessary during composite processing to ensure component uniformity. To determine the thermal properties of CFCC materials, and particularly for detecting defects and nonuniformities, the authors have developed an infrared thermal imaging method to provide a single-shot full-field measurement of thermal diffusivity distributions in large components. This method requires that the back surface of a specimen receives a thermal pulse of short duration and that the temperature of the front surface is monitored as a function of time. The system has been used to measure thermal diffusivities of several CFCC materials with known porosity or density values, including SYLRAMIC{trademark} SiC/SiNC composite samples from Dow Corning and SiC/SiC and enhanced SiC/SiC samples from DuPont Lanxide Composites, to determine the relationship of thermal diffusivity to component porosity or density.

Sun, J.G.; Deemer, C.; Ellingson, W.A. [Argonne National Lab., IL (United States). Energy Technology Div.; Easler, T.E.; Szweda, A. [Dow Corning Corp., Midland, MI (United States); Craig, P.A. [DuPont Lanxide Composites Inc., Newark, DE (United States)

1997-09-01T23:59:59.000Z

125

STRUCTURE-MECHANICAL PROPERTY RELATIONSHIPS IN A BIOLOGICAL CERAMIC-POLYMER COMPOSITE: NACRE  

E-Print Network [OSTI]

171 STRUCTURE-MECHANICAL PROPERTY RELATIONSHIPS IN A BIOLOGICAL CERAMIC-POLYMER COMPOSITE: NACRE, a laminated ceramic- polymer biocompositefound in seashell. Four-pointbending strength and three-point bend and ultramicrotomedsections with and without the intactarago- nite platelets. We found that the organic matrix is indeed

Aksay, Ilhan A.

126

The role of adhesive in the ballistic/structural performance of ceramic/polymermatrix composite hybrid armor  

E-Print Network [OSTI]

The role of adhesive in the ballistic/structural performance of ceramic/polymer­matrix composite strength and good thermal stability of these materials; (b) development of ceramic matrix composites [1­3] ­ whiskers or fiber reinforcements within the ceramic matrix are utilized in this case in order to address

Grujicic, Mica

127

Front-flash thermal imaging characterization of continuous fiber ceramic composites.  

SciTech Connect (OSTI)

Infrared thermal imaging has become increasingly popular as a nondestructive evaluation method for characterizing materials and detecting defects. One technique, which was utilized in this study, is front-flash thermal imaging. We have developed a thermal imaging system that uses this technique to characterize advanced material systems, including continuous fiber ceramic composite (CFCC) components. In a front-flash test, pulsed heat energy is applied to the surface of a sample, and decay of the surface temperature is then measured by the thermal imaging system. CFCC samples with drilled flat-bottom holes at the back surface (to serve as ''flaws'') were examined. The surface-temperature/time relationship was analyzed to determine the depths of the flaws from the front surface of the CFCC material. Experimental results on carbon/carbon and CFCC samples are presented and discussed.

Deemer, C.

1999-04-23T23:59:59.000Z

128

Life prediction methodology for ceramic components of advanced heat engines. Phase 1: Volume 2, Appendices  

SciTech Connect (OSTI)

This volume presents the following appendices: ceramic test specimen drawings and schematics, mixed-mode and biaxial stress fracture of structural ceramics for advanced vehicular heat engines (U. Utah), mode I/mode II fracture toughness and tension/torsion fracture strength of NT154 Si nitride (Brown U.), summary of strength test results and fractography, fractography photographs, derivations of statistical models, Weibull strength plots for fast fracture test specimens, and size functions.

NONE

1995-03-01T23:59:59.000Z

129

Investigation of properties and performance of ceramic composite components: Final report on Phases 3 and 4  

SciTech Connect (OSTI)

The objective of the Fossil Energy Advanced Research and Technology Development (AR and TD) Materials Program is to conduct research and development on materials for longer-term fossil energy applications as well as for generic needs of various fossil fuel technologies. The research program of the Materials Response Group at Virginia Tech addresses the need for reliable and durable structural ceramic composites to perform in high temperature environments. The research effort provides an experimental and analytical basis for the transition from properties of materials to performance of actual component structures. Phases 1 and 2 of the present program focused on the development of test capabilities, initial studies of component mechanical response under various conditions and the development of a life prediction methodology. These efforts have been described in previous reports. This report summarizes the major tasks completed under Phases 3 and 4 of the project. Overall, the authors have made significant progress in a broad spectrum of tasks in this program. Their efforts have encompassed component evaluation, assessment of new SiC-based composites with improved high-temperature potential, development of oxide coating materials for SiC, and the extension and development of new models for predicting the durability of composite components under specific operating conditions for various CMC applications. Each of these areas of work is an important area for achieving the ultimate goal of usable SiC-based composites in high-temperature corrosive environments typical of fossil energy applications.

Curtin, W.A.; Halverson, H.; Carter, R.H.; Miraj, N.; Reifsnider, K.L. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States)

1998-01-15T23:59:59.000Z

130

Effects of Thermal Aging on the Mechanical Properties of a Porous-Matrix Ceramic Composite  

E-Print Network [OSTI]

Effects of Thermal Aging on the Mechanical Properties of a Porous-Matrix Ceramic Composite Eric A properties of an all-oxide fiber-reinforced composite following long-term exposure (1000 h) at temperatures of 1000­1200°C in air. The composite of interest derives its damage tolerance from a highly porous matrix

Zok, Frank

131

BALLISTIC PROPERTIES OF POLYMER MATRIX COMPOSITES AND CERAMIC PLATES USED IN ARMOR DESIGN  

E-Print Network [OSTI]

BALLISTIC PROPERTIES OF POLYMER MATRIX COMPOSITES AND CERAMIC PLATES USED IN ARMOR DESIGN Mehmet from polymer matrix composites due to lightweight and good ballistic properties. The requirement for protection especially for polymer matrix composites because total back-side deformation (elastic and plastic

Soykasap, Omer

132

Metal matrix composite of an iron aluminide and ceramic particles and method thereof  

DOE Patents [OSTI]

A metal matrix composite comprising an iron aluminide binder phase and a ceramic particulate phase such as titanium diboride, zirconium diboride, titanium carbide and tungsten carbide is made by heating a mixture of iron aluminide powder and particulates of one of the ceramics such as titanium diboride, zirconium diboride, titanium carbide and tungsten carbide in a alumina crucible at about 1450.degree. C. for about 15 minutes in an evacuated furnace and cooling the mixture to room temperature. The ceramic particulates comprise greater than 40 volume percent to about 99 volume percent of the metal matrix composite.

Schneibel, Joachim H. (Maryville, TN)

1997-01-01T23:59:59.000Z

133

Metal matrix composite of an iron aluminide and ceramic particles and method thereof  

DOE Patents [OSTI]

A metal matrix composite comprising an iron aluminide binder phase and a ceramic particulate phase such as titanium diboride, zirconium diboride, titanium carbide and tungsten carbide is made by heating a mixture of iron aluminide powder and particulates of one of the ceramics such as titanium diboride, zirconium diboride, titanium carbide and tungsten carbide in a alumina crucible at about 1,450 C for about 15 minutes in an evacuated furnace and cooling the mixture to room temperature. The ceramic particulates comprise greater than 40 volume percent to about 99 volume percent of the metal matrix composite.

Schneibel, J.H.

1997-06-10T23:59:59.000Z

134

Advanced Manufacturing: Using Composites for Clean Energy  

Broader source: Energy.gov [DOE]

Advanced fiber-reinforced polymer composites, which combine strong fibers with tough plastics, are lighter and stronger than steel. These materials could lower overall production costs in U.S. manufacturing and ultimately drive the adoption of a new clean energy way of life.

135

Ceramic composites reinforced with modified silicon carbide whiskers and method for modifying the whiskers  

DOE Patents [OSTI]

Silicon carbide whisker-reinforced ceramic composites are fabricated in a highly reproducible manner by beneficating the surfaces of the silicon carbide whiskers prior to their usage in the ceramic composites. The silicon carbide whiskers which contain considerable concentrations of surface oxides and other impurities which interact with the ceramic composite material to form a chemical bond are significantly reduced so that only a relatively weak chemical bond is formed between the whisker and the ceramic material. Thus, when the whiskers interact with a crack propagating into the composite the crack is diverted or deflected along the whisker-matrix interface due to the weak chemical bonding so as to deter the crack propagation through the composite. The depletion of the oxygen-containing compounds and other impurities on the whisker surfaces and near surface region is effected by heat treating the whiskers in a suitable oxygen sparging atmosphere at elevated temperatures. Additionally, a sedimentation technique may be utilized to remove whiskers which suffer structural and physical anomalies which render them undesirable for use in the composite. Also, a layer of carbon may be provided on the surface of the whiskers to further inhibit chemical bonding of the whiskers to the ceramic composite material.

Tiegs, T.N.; Lindemer, T.B.

1991-02-19T23:59:59.000Z

136

Ceramic composites reinforced with modified silicon carbide whiskers and method for modifying the whiskers  

DOE Patents [OSTI]

Silicon carbide whisker-reinforced ceramic composites are fabricated in a highly reproducible manner by beneficating the surfaces of the silicon carbide whiskers prior to their usage in the ceramic composites. The silicon carbide whiskers which contain considerable concentrations of surface oxides and other impurities which interact with the ceramic composite material to form a chemical bond are significantly reduced so that only a relatively weak chemical bond is formed between the whisker and the ceramic material. Thus, when the whiskers interact with a crack propagating into the composite the crack is diverted or deflected along the whisker-matrix interface due to the weak chemical bonding so as to deter the crack propagation through the composite. The depletion of the oxygen-containing compounds and other impurities on the whisker surfaces and near surface region is effected by heat treating the whiskers in a suitable oxygen sparaging atmosphere at elevated temperatures. Additionally, a sedimentation technique may be utilized to remove whiskers which suffer structural and physical anomalies which render them undesirable for use in the composite. Also, a layer of carbon may be provided on the surface of the whiskers to further inhibit chemical bonding of the whiskers to the ceramic composite material.

Tiegs, Terry N. (Lenoir City, TN); Lindemer, Terrence B. (Oak Ridge, TN)

1991-01-01T23:59:59.000Z

137

Low Temperature Oxidation Embrittlement of CAS/Nicalon Ceramic Matrix Composites  

SciTech Connect (OSTI)

The influence of extended duration (up to 1,000 h), low temperature oxidation heat-treatments (375-600 C) has been assessed using a model ceramic matrix composite system with a graphitic fiber/matrix interphase. For this study a Nicalon fiber reinforced CaO-Al2O3-SiO2 matrix composite was selected (CAS/Nicalon), which possesses a thin (~20-40 nm) carbon-based interphase. Oxidation exposure has been conducted under both unloaded and static fatigue loaded conditions. For unstressed oxidation exposure, degradation of the carbon-based interphase is apparent at temperatures as low as 375 C, after 1,000 h exposure, resulting in a transition to a nominally brittle failure mode (i.e. negligible fiber pull-out). The degree of mechanical property degradation increases with increasing temperatures, such that strength degradation, and a transition to nominally brittle failure, is apparent after just 10 h at 600 C. Static fatigue loading between 450 and 600C demonstrated generally similar trends, with reduced lifetimes being observed with increasing temperature. Based upon the unloaded oxidation experiments, combined with previously obtained intermediate and high temperature oxidation stability studies, a simple environmental embrittlement failure mechanism map is presented for CAS/Nicalon. The implications of this study for advanced composite designs with multiple thin carbon-based interphase layers are also discussed.

Plucknett, Kevin P [Dalhousie University, Halifax, Nova Scotia, CANADA; Lin, Hua-Tay [ORNL

2007-01-01T23:59:59.000Z

138

advanced composites production: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Next Page Last Page Topic Index 1 ULTRASONIC CHARACTERIZATION OF ADVANCED COMPOSITE MATERIALS CiteSeer Summary: With increased use of composite materials in critical structural...

139

advanced composite material: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Next Page Last Page Topic Index 1 ULTRASONIC CHARACTERIZATION OF ADVANCED COMPOSITE MATERIALS CiteSeer Summary: With increased use of composite materials in critical structural...

140

advanced composite aileron: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Next Page Last Page Topic Index 1 ULTRASONIC CHARACTERIZATION OF ADVANCED COMPOSITE MATERIALS CiteSeer Summary: With increased use of composite materials in critical structural...

Note: This page contains sample records for the topic "advanced ceramic composites" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Determining thermal diffusivity and defect attributes in ceramic matrix composites by infrared imaging.  

SciTech Connect (OSTI)

Ceramic matrix composites are being developed for numerous high temperature applications, including rotors and combustors for advanced turbine engines, heat exchanger and hot-gas filters for coal gasification plants. Among the materials of interest are silicon-carbide-fiber-reinforced-silicon-carbide (SiC{sub (f)}/SiC), silicon-carbide-fiber-reinforced-silicon-nitride (SiC{sub (f)}/Si{sub 3}N{sub 4}), aluminum-oxide-reinforced-alumina (Al{sub 2}O{sub 3(f)}/Al{sub 2}O{sub 3}), etc. In the manufacturing of these ceramic composites, the conditions of the fiber/matrix interface are critical to the mechanical and thermal behavior of the component. Defects such as delaminations and non-uniform porosity can directly effect the performance. A nondestructive evaluation (NDE) method, developed at Argonne National Laboratory has proved beneficial in analyzing as-processed conditions and defect detection created during manufacturing. This NDE method uses infrared thermal imaging for fill-field quantitative measurement of the distribution of thermal diffusivity in large components. Intensity transform algorithms have been used for contrast enhancement of the output image. Nonuniformity correction and automatic gain control are used to dynamically optimize video contrast and brightness, providing additional resolution in the acquired images. Digital filtering, interpolation, and least-squares-estimation techniques have been incorporated for noise reduction and data acquisition. The Argonne NDE system has been utilized to determine thermal shock damage, density variations, and variations in fiber coating in a full array of test specimens.

Ahuja, S.; Ellingson, W. A.; Koehl, E. R.; Stuckey, J.

1997-12-05T23:59:59.000Z

142

i Am Cerom Soc 741111 2802-808 (19911 Estimation of Interfacial Shear in Ceramic Composites from  

E-Print Network [OSTI]

/ matrix interface in fiber-reinforced ceramics. For example, Marshall developed a straightforward the interfacial shear stress in polymeric-matrix, metal-matrix, and ceramic-matrix com- posites. A relatedi Am Cerom Soc 741111 2802-808 (19911 journal Estimation of Interfacial Shear in Ceramic Composites

Barber, James R.

143

A novel biomimetic approach to the design of high-performance ceramic/metal composites  

SciTech Connect (OSTI)

The prospect of extending natural biological design to develop new synthetic ceramic-metal composite materials is examined. Using ice-templating of ceramic suspensions and subsequent metal infiltration, we demonstrate that the concept of ordered hierarchical design can be applied to create fine-scale laminated ceramic-metal (bulk) composites that are inexpensive, lightweight and display exceptional damage-tolerance properties. Specifically, Al{sub 2}O{sub 3}/Al-Si laminates with ceramic contents up to approximately 40 vol% and with lamellae thicknesses down to 10 {micro}m were processed and characterized. These structures achieve an excellent fracture toughness of 40 MPa{radical}m at a tensile strength of approximately 300 MPa. Salient toughening mechanisms are described together with further toughening strategies.

Launey, Maximilien E.; Munch, Etienne; Alsem, Daan Hein; Saiz, Eduardo; Tomsia, Antoni P.; Ritchie, Robert O.

2009-08-01T23:59:59.000Z

144

Effects of Matrix Cracks on the Thermal Diffusivity of a Fiber-Reinforced Ceramic Composite  

E-Print Network [OSTI]

Effects of Matrix Cracks on the Thermal Diffusivity of a Fiber-Reinforced Ceramic Composite of Engineering Science, University of Western Ontario, London, Ontario N6A 5B9, Canada Effects of matrix cracks conductances coupled with a unit cell model for a fiber composite containing a periodic array of matrix cracks

Zok, Frank

145

Microwave joining of SiC ceramics and composites  

SciTech Connect (OSTI)

Potential applications of SiC include components for advanced turbine engines, tube assemblies for radiant burners and petrochemical processing and heat exchangers for high efficiency electric power generation systems. Reliable methods for joining SiC are required in order to cost-effectively fabricate components for these applications from commercially available shapes and sizes. This manuscript reports the results of microwave joining experiments performed using two different types of SiC materials. The first were on reaction bonded SiC, and produced joints with fracture toughness equal to or greater than that of the base material over an extended range of joining temperatures. The second were on continuous fiber-reinforced SiC/SiC composite materials, which were successfully joined with a commercial active brazing alloy, as well as by using a polymer precursor.

Ahmad, I.; Silberglitt, R.; Tian, Y.L. [FM Technologies, Inc., Fairfax, VA (United States); Katz, J.D. [Los Alamos National Lab., NM (United States)

1997-04-01T23:59:59.000Z

146

Ceramic Component Development Process Analysis  

SciTech Connect (OSTI)

The development of ceramic components and coatings is critical to the demonstration of advanced fossil energy systems. Ceramic components and coating will play critical role in hot-gas filtration, high- temperature heat exchangers, thermal barrier coatings, and the hot- section of turbines. Continuous-fiber composites (CFCC) are expected to play an increasing role in these applications. This program encompassed five technical areas related to ceramic component development for fossil energy systems.

Boss, D.; Sambasivan, S.; Kuehmann, C. [Northwestern Univ., Evanston, IL (United States). Basic Industrial Research Lab.; Faber, K. [Northwestern University, MEAS Materials Science & Engineering, Evanston, IL (United States)

1996-12-31T23:59:59.000Z

147

Innovative grinding wheel design for cost-effective machining of advanced ceramics. Phase I, final report  

SciTech Connect (OSTI)

Norton Company successfully completed the 16-month Phase I technical effort to define requirements, design, develop, and evaluate a next-generation grinding wheel for cost-effective cylindrical grinding of advanced ceramics. This program was a cooperative effort involving three Norton groups representing a superabrasive grinding wheel manufacturer, a diamond film manufacturing division and a ceramic research center. The program was divided into two technical tasks, Task 1, Analysis of Required Grinding Wheel Characteristics, and Task 2, Design and Prototype Development. In Task 1 we performed a parallel path approach with Superabrasive metal-bond development and the higher technical risk, CVD diamond wheel development. For the Superabrasive approach, Task 1 included bond wear and strength tests to engineer bond-wear characteristics. This task culminated in a small-wheel screening test plunge grinding sialon disks. In Task 2, an improved Superabrasive metal-bond specification for low-cost machining of ceramics in external cylindrical grinding mode was identified. The experimental wheel successfully ground three types of advanced ceramics without the need for wheel dressing. The spindle power consumed by this wheel during test grinding of NC-520 sialon is as much as to 30% lower compared to a standard resin bonded wheel with 100 diamond concentration. The wheel wear with this improved metal bond was an order of magnitude lower than the resin-bonded wheel, which would significantly reduce ceramic grinding costs through fewer wheel changes for retruing and replacements. Evaluation of ceramic specimens from both Tasks 1 and 2 tests for all three ceramic materials did not show evidence of unusual grinding damage. The novel CVD-diamond-wheel approach was incorporated in this program as part of Task 1. The important factors affecting the grinding performance of diamond wheels made by CVD coating preforms were determined.

Licht, R.H.; Ramanath, S.; Simpson, M.; Lilley, E.

1996-02-01T23:59:59.000Z

148

Thermal diffusivity imaging of continuous fiber ceramic composite materials and components  

SciTech Connect (OSTI)

Continuous-fiber ceramic matrix composites (CFCCs) are currently being developed for various high-temperature applications, including use in advanced turbine engines. In such composites, the condition of the interfaces between the fibers and matrix or between laminae in a two-dimensional weave lay-up are critical to the mechanical and thermal behavior of the component. A nondestructive evaluation method that could be used to assess the interface condition and/or detect other `defects` has been developed at Argonne National Laboratory (ANL) and uses infrared thermal imaging to provide `single-shot` full- field quantitative measurement of the distribution of thermal diffusivity in large components. By applying digital filtering, interpolation, and least-squares-estimation techniques for noise reduction, shorter acquisition and analysis times have been achieved with submillimeter spatial resolution for materials with a wide range of `thermal thicknesses`. The system at ANL has been used to examine the effects of thermal shock, oxidation treatment, density variations, and variations in fiber coating in a full array of test specimens. In addition, actual subscale CFCC components of nonplanar geometries have been inspected for manufacturing-induced variations in thermal properties.

Ahuja, S.; Ellingson, W.A. [Argonne National Lab., IL (United States); Steckenrider, J.S. [Northwestern Univ., Evanston, IL (United States); King, S. [Argonne National Lab., IL (United States)

1995-12-31T23:59:59.000Z

149

Dielectric response of high permittivity polymer ceramic composite with low loss tangent  

SciTech Connect (OSTI)

The present communication investigates the dielectric response of the Sr{sub 9}Ce{sub 2}Ti{sub 12}O{sub 36} ceramics loaded high density polyethylene and epoxy resin. Sr{sub 9}Ce{sub 2}Ti{sub 12}O{sub 36} ceramic filled polyethylene and epoxy composites were prepared using hot blending and mechanical mixing, respectively. 40 vol % ceramic loaded polyethylene has relative permittivity of 12.1 and loss tangent of 0.004 at 8 GHz, whereas the corresponding composite using epoxy as matrix has permittivity and loss tangent of 14.1 and 0.022, respectively. The effective medium theory fits relatively well for the observed permittivity of these composites.

Subodh, G. [Materials and Minerals Division, National Institute for Interdisciplinary Science and Technology, Thiruvanathapuram 695019 (India); 1.Physikalisches Institut, Universitat Stuttgart, Pfaffenwaldring 57, Stuttgart 70550 (Germany); Deepu, V.; Mohanan, P. [Department of Electronics, Cochin University of Science and Technology, Cochin 682 022 (India); Sebastian, M. T. [Materials and Minerals Division, National Institute for Interdisciplinary Science and Technology, Thiruvanathapuram 695019 (India)

2009-08-10T23:59:59.000Z

150

Method for producing melt-infiltrated ceramic composites using formed supports  

DOE Patents [OSTI]

A method for producing shaped articles of ceramic composites provides a high degree of dimensional tolerance to these articles. A fiber preform is disposed on a surface of a stable formed support, a surface of which is formed with a plurality of indentations, such as grooves, slots, or channels. Precursors of ceramic matrix materials are provided to the fiber preform to infiltrate from both sides of the fiber preform. The infiltration is conducted under vacuum at a temperature not much greater than a melting point of the precursors. The melt-infiltrated composite article substantially retains its dimension and shape throughout the fabrication process.

Corman, Gregory Scot (Ballston Lake, NY); Brun, Milivoj Konstantin (Ballston Lake, NY); McGuigan, Henry Charles (Duanesburg, NY)

2003-01-01T23:59:59.000Z

151

Fundamental alloy design of oxide ceramics and their composites. [Annual] report, May 1, 1990--August 31, 1992  

SciTech Connect (OSTI)

The main research was on microstructural development of oxide ceramics. Projects were completed and the publications given. Abstracts are given on: Reactive CeO{sub 2}powders by homogeneous precipitation, SiC whisker-reinforced lithium aluminosilicate composite, solute drag on grain boundary in ionic solids (space charge effect), in-situ alumina/aluminate platelet composites, exaggerated texture and grain growth of superplastic silicon nitride (SiAlON), hot extrusion of ceramics, control of grain boundary pinning in Al{sub 2}O{sub 3}/ZrO{sub 2} composites with Ce{sup 3+}/Ce{sup 4+} doping, superplastic forming of ceramic composites, computer simulation of final stage sintering (model, kinetics, microstructure, effect of initial pore size), development of superplastic structural ceramics, and superplastic flow of two-phase ceramics containing rigid inclusions (zirconia/mullite composites). A proposed research program is outlined: materials, solute drag, densification and coarsening, and grain boundary electrical behavior.

Chen, I.W.

1992-12-31T23:59:59.000Z

152

Process for making a titanium diboride-chromium diboride-yttrium titanium oxide ceramic composition  

DOE Patents [OSTI]

A ceramic composition composition is described. The ceramic composition consists essentially of from about 84 to 96 w/o titanium diboride, from about 1 to 9 w/o chromium diboride, and from about 3 to aobut 15 w/o yttrium-titanium-oxide. A method of making the ceramic composition is also described. The method of making the ceramic composition comprises the following steps: Step 1--A consolidated body containing stoichiometric quantities of titanium diboride and chromium diboride is provided. Step 2--The consolidated body is enclosed in and in contact with a thermally insulated package of yttria granules having a thickness of at least 0.5 inches. Step 3--The consolidated body enclosed in the thermally insulated package of yttria granules is heated in a microwave oven with microwave energy to a temperature equal to or greater than 1,900 degrees centigrade to sinter and uniformly disperse yttria particles having a size range from about 1 to about 12 microns throughout the consolidated body forming a densified body consisting essentially of titanium diboride, chromium diboride, and yttrium-titanium-oxide. The resulting densified body has enhanced fracture toughness and hardness.

Holcombe, Cressie E. (Knoxville, TN); Dykes, Norman L. (Oak Ridge, TN)

1992-01-01T23:59:59.000Z

153

Development of ceramic composite hot-gas filters  

SciTech Connect (OSTI)

A novel type of hot-gas filter based on a ceramic fiber-reinforced ceramic matrix was developed and extended to fullsize, 60-mm OD by 1.5-meter-long, candle filters. A commercially viable process for producing the filters was developed, and the filters are undergoing testing and demonstration throughout the world for applications in pressurized fluidized-bed combustion (PFBC) and integrated gasification combined cycle (IGCC) plants. Development activities at Oak Ridge National Laboratory (ORNL) and at the 3M Company, and testing at the Westinghouse Science and Technology Center (STC) are presented. Demonstration tests at the Tidd PFBC are underway. Issues identified during the testing and demonstration phases of the development are discussed. Resolution of the issues and the status of commercialization of the filters are described.

Judkins, R.R.; Stinton, D.P. [Oak Ridge National Lab., TN (United States); Smith, R.G.; Fischer, E.M.; Eaton, J.H.; Weaver, B.L.; Kahnke, J.L.; Pysher, D.J. [3M Co., St. Paul, MN (United States)

1995-04-01T23:59:59.000Z

154

Infrared-based NDE methods for determining thermal properties and defects in ceramic composites  

SciTech Connect (OSTI)

Continuous-fiber ceramic matrix composites are currently being developed for various high temperature applications, including use in advanced heat engines. In the material classes of interest for such applications, i.e., silicon carbide (SiC)-fiber-reinforced SiC (SiC{sub (f)}/SiC), SiC-fiber-reinforced silicon nitride (SiC{sub (f)}/Si{sub 3}N{sub 4}), Al{sub 2}O{sub 3 (f)}/Al{sub 2}O{sub 3}, etc., the condition of the interface between the fibers and matrix is critical to the mechanical and thermal behavior of each component. A nondestructive evaluation method developed at Argonne National Laboratory uses infrared thermal imaging to provide ``single-shot`` full-field measurement of the distribution of thermal diffusivity in large components. By applying digital filtering, interpolation, and least-squares-estimation techniques for noise reduction, the authors have achieved acquisition and analysis times of minutes or less with submillimeter spatial resolution. The system has been used to examine the effects of thermal shock, oxidation treatment, density, and variations in fiber coatings in a full array of test specimens.

Ahuja, S.; Ellingson, W.A. [Argonne National Lab., IL (United States). Energy Technology Div.; Steckenrider, J.S. [Northwestern Univ., Evanston, IL (United States); Koch, S. [Univ. of Michigan, Ann Arbor, MI (United States)

1996-08-01T23:59:59.000Z

155

Process for making a titanium diboride-chromium diboride-yttrium titanium oxide ceramic composition  

DOE Patents [OSTI]

A ceramic composition is described. The ceramic composition consists essentially of from about 84 to 96 w/o titanium diboride, from about 1 to 9 w/o chromium diboride, and from about 3 to about 15 w/o yttrium-titanium-oxide. A method of making the ceramic composition is also described. The method of making the ceramic composition comprises the following steps: Step 1--A consolidated body containing stoichiometric quantities of titanium diboride and chromium diboride is provided. Step 2--The consolidated body is enclosed in and in contact with a thermally insulated package of yttria granules having a thickness of at least 0.5 inches. Step 3--The consolidated body enclosed in the thermally insulated package of yttria granules is heated in a microwave oven with microwave energy to a temperature equal to or greater than 1,900 degrees centigrade to sinter and uniformly disperse yttria particles having a size range from about 1 to about 12 microns throughout the consolidated body forming a densified body consisting essentially of titanium diboride, chromium diboride, and yttrium-titanium-oxide. The resulting densified body has enhanced fracture toughness and hardness. No Drawings

Holcombe, C.E.; Dykes, N.L.

1992-04-28T23:59:59.000Z

156

High-temperature electrically conductive ceramic composite and method for making same  

DOE Patents [OSTI]

The present invention relates to a metal-oxide ceramic composition useful in induction heating applications for treating uranium and uranium alloys. The ceramic composition is electrically conductive at room temperature and is nonreactive with molten uranium. The composition is prepared from a particulate admixture of 20 to 50 vol. % niobium and zirconium oxide which may be stabilized with an addition of a further oxide such as magnesium oxide, calcium oxide, or yttria. The composition is prepared by blending the powders, pressing or casting the blend into the desired product configuration, and then sintering the casting or compact in an inert atmosphere. In the casting operation, calcium aluminate is preferably added to the admixture in place of a like quantity of zirconia for providing a cement to help maintain the integrity of the sintered product.

Beck, David E. (Knoxville, TN); Gooch, Jack G. (Seymour, TN); Holcombe, Jr., Cressie E. (Knoxville, TN); Masters, David R. (Knoxville, TN)

1983-01-01T23:59:59.000Z

157

Next generation grinding spindle for cost-effective manufacture of advanced ceramic components  

SciTech Connect (OSTI)

Finish grinding of advanced structural ceramics has generally been considered an extremely slow and costly process. Recently, however, results from the High-Speed, Low-Damage (HSLD) program have clearly demonstrated that numerous finish-process performance benefits can be realized by grinding silicon nitride at high wheel speeds. A new, single-step, roughing-process capable of producing high-quality silicon nitride parts at high material removal rates while dramatically reducing finishing costs has been developed.

Kovach, J.A.; Laurich, M.A.

2000-01-01T23:59:59.000Z

158

ADVANCED ELECTRON BEAM TECHNIQUES FOR METALLIC AND CERAMIC PROTECTIVE COATING SYSTEMS  

E-Print Network [OSTI]

cobalt and chromium. Ceramic or thermal barrier coatings canin fuel usage. Also, ceramic or thermal barrier coatings~n Oslo developed ceramic or thermal barrier coatings that

Boone, Donald H.

2013-01-01T23:59:59.000Z

159

Use of high temperature insulation for ceramic matrix composites in gas turbines  

DOE Patents [OSTI]

A ceramic composition for insulating components, made of ceramic matrix composites, of gas turbines is provided. The composition comprises a plurality of hollow oxide-based spheres of various dimensions, a phosphate binder, and at least one oxide filler powder, whereby the phosphate binder partially fills gaps between the spheres and the filler powders. The spheres are situated in the phosphate binder and the filler powders such that each sphere is in contact with at least one other sphere and the arrangement of spheres is such that the composition is dimensionally stable and chemically stable at a temperature of approximately 1600.degree. C. A stationary vane of a gas turbine comprising the composition of the present invention bonded to the outer surface of the vane is provided. A combustor comprising the composition bonded to the inner surface of the combustor is provided. A transition duct comprising the insulating coating bonded to the inner surface of the transition is provided. Because of abradable properties of the composition, a gas turbine blade tip seal comprising the composition also is provided. The composition is bonded to the inside surface of a shroud so that a blade tip carves grooves in the composition so as to create a customized seal for the turbine blade tip.

Morrison, Jay Alan (Orlando, FL); Merrill, Gary Brian (Pittsburgh, PA); Ludeman, Evan McNeil (New Boston, NH); Lane, Jay Edgar (Murrysville, PA)

2001-01-01T23:59:59.000Z

160

Low cost fabrication of silicon carbide based ceramics and fiber reinforced composites  

SciTech Connect (OSTI)

A low cost processing technique called reaction forming for the fabrication of near-net and complex shaped components of silicon carbide based ceramics and composites is presented. This process consists of the production of a microporous carbon preform and subsequent infiltration with liquid silicon or silicon-refractory metal alloys. The microporous preforms are made by the pyrolysis of a polymerized resin mixture with very good control of pore volume and pore size thereby yielding materials with tailorable microstructure and composition. Mechanical properties (elastic modulus, flexural strength, and fracture toughness) of reaction-formed silicon carbide ceramics are presented. This processing approach is suitable for various kinds of reinforcements such as whiskers, particulates, fibers (tows, weaves, and filaments), and 3-D architectures. This approach has also been used to fabricate continuous silicon carbide fiber reinforced ceramic composites (CFCC`s) with silicon carbide based matrices. Strong and tough composites with tailorable matrix microstructure and composition have been obtained. Microstructure and thermomechanical properties of a silicon carbide (SCS-6) fiber reinforced reaction-formed silicon carbide matrix composites are discussed.

Singh, M.; Levine, S.R.

1995-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "advanced ceramic composites" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Titanium diboride ceramic fiber composites for Hall-Heroult cells  

DOE Patents [OSTI]

An improved cathode structure for Hall-Heroult cells for the electrolytic production of aluminum metal. This cathode structure is a preform fiber base material that is infiltrated with electrically conductive titanium diboride using chemical vapor infiltration techniques. The structure exhibits good fracture toughness, and is sufficiently resistant to attack by molten aluminum. Typically, the base can be made from a mat of high purity silicon carbide fibers. Other ceramic or carbon fibers that do not degrade at temperatures below about 1000 deg. C can be used.

Besmann, Theodore M. (Knoxville, TN); Lowden, Richard A. (Knoxville, TN)

1990-01-01T23:59:59.000Z

162

Titanium diboride ceramic fiber composites for Hall-Heroult cells  

DOE Patents [OSTI]

An improved cathode structure is described for Hall-Heroult cells for the electrolytic production of aluminum metal. This cathode structure is a preform fiber base material that is infiltrated with electrically conductive titanium diboride using chemical vapor infiltration techniques. The structure exhibits good fracture toughness, and is sufficiently resistant to attack by molten aluminum. Typically, the base can be made from a mat of high purity silicon carbide fibers. Other ceramic or carbon fibers that do not degrade at temperatures below about 1000 C can be used.

Besmann, T.M.; Lowden, R.A.

1990-05-29T23:59:59.000Z

163

Full-field characterization of thermal diffusivity in continuous- fiber ceramic composite materials and components  

SciTech Connect (OSTI)

Continuous-fiber ceramic matrix composites (CFCCs) are currently being developed for various high-temperature applications, including use in advanced heat engines. Among the material classes of interest for such applications are silicon carbide (SiC)-fiber-reinforced SiC (SiC{sub (f)}/SiC), SiC-fiber-reinforced silicon nitride (SiC {sub (f)}/Si{sub 3}N{sub 4}), aluminum oxide (Al{sub 2}O{sub 3})-fiber-reinforced Al{sub 2}O{sub 3} (Al{sub 2}O{sub 3}{sub (f)}/Al{sub 2}O{sub 3}), and others. In such composites, the condition of the interfaces (between the fibers and matrix) are critical to the mechanical and thermal behavior of the component (as are conventional mechanical defects such as cracks, porosity, etc.). For example, oxidation of this interface (especially on carbon coated fibers) can seriously degrade both mechanical and thermal properties. Furthermore, thermal shock damage can degrade the matrix through extensive crack generation. A nondestructive evaluation method that could be used to assess interface condition, thermal shock damage, and to detect other ``defects`` would thus be very beneficial, especially if applicable to full-scale components. One method under development uses infrared thermal imaging to provide ``single-shot`` full-field assessment of the distribution of thermal properties in large components by measuring thermal diffusivity. By applying digital image filtering, interpolation, and least-squares-estimation techniques for noise reduction, we can achieve acquisition and analysis times of minutes or less with submillimeter spatial resolution. The system developed at Argonne has been used to examine the effects of thermal shock, oxidation treatment, density variations, and variations in oxidation resistant coatings in a full array of test specimens. Subscale CFCC components with nonplanar geometries have also been studied for manufacturing-induced variations in thermal properties.

Steckenrider, J.S.; Ellingson, W.A. [Argonne National Lab., IL (United States); Rothermel, S.A. [South Dakota State Univ., Brookings, SD (United States)

1995-05-01T23:59:59.000Z

164

Advanced Materials and Processing of Composites for High Volume...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Applications (ACC932) Advanced Materials and Processing of Composites for High Volume Applications (ACC932) 2012 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies...

165

Advanced Materials and Processing of Composites for High Volume...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

-- Washington D.C. lm021zaluzec2010o.pdf More Documents & Publications Advanced Materials and Processing of Composites for High Volume Applications ACC115 High Volume...

166

Use of advanced composite materials for innovative building design solutions/  

E-Print Network [OSTI]

Advanced composite materials become popular in construction industry for the innovative building design solutions including strengthening and retrofitting of existing structures. The interface between different materials ...

Lau, Tak-bun, Denvid

2009-01-01T23:59:59.000Z

167

advanced composite structure: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 ADVANCED COMPOSITE MATERIALS IN BRIDGES AND STRUCTURES MATRIAUX COMPOSITES D'AVANT-GARDE POUR PONTS ET CHARPENTES...

168

advanced composite structures: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 ADVANCED COMPOSITE MATERIALS IN BRIDGES AND STRUCTURES MATRIAUX COMPOSITES D'AVANT-GARDE POUR PONTS ET CHARPENTES...

169

Partial-Transient-Liquid-Phase Bonding of Advanced Ceramics Using Surface-Modified Interlayers  

E-Print Network [OSTI]

of Thermal Residual Stresses in Joining Ceramics with ThinIn ceramic/metal/ceramic bonds that undergo thermal cycling,cooling or thermal cycling of the component. Ceramics are

Reynolds, Thomas Bither

2012-01-01T23:59:59.000Z

170

Process for the preparation of fiber-reinforced ceramic composites by chemical vapor deposition  

DOE Patents [OSTI]

A chemical vapor deposition (CVD) process for preparing fiber-reinforced ceramic composites. A specially designed apparatus provides a steep thermal gradient across the thickness of a fibrous preform. A flow of gaseous ceramic matrix material is directed into the fibrous preform at the cold surface. The deposition of the matrix occurs progressively from the hot surface of the fibrous preform toward the cold surface. Such deposition prevents the surface of the fibrous preform from becoming plugged. As a result thereof, the flow of reactant matrix gases into the uninfiltrated (undeposited) portion of the fibrous preform occurs throughout the deposition process. The progressive and continuous deposition of ceramic matrix within the fibrous preform provides for a significant reduction in process time over known chemical vapor deposition processes.

Lackey, Jr., Walter J. (Oak Ridge, TN); Caputo, Anthony J. (Knoxville, TN)

1986-01-01T23:59:59.000Z

171

US Department of Energy`s continuous fiber ceramic composite program - components for industrial use  

SciTech Connect (OSTI)

U.S. industry has a critical need for materials that are light, strong, corrosion resistant, and capable of performing in high temperature environments. The U.S. Department of Energy`s Continuous Fiber Ceramic Composite (CFCC) Program is addressing this critical industrial need. Although many traditional ceramics perform well at high temperature, they typically fail in a catastrophic manner in industrial service. CFCCs are the solution to this problem. A CFCC is made by placing a ceramic matrix around reinforcing continuous fibers that have been placed or woven into a preform. The resulting CFCC is a high temperature resistant material that exhibits tough behavior with better in-service reliability. Various CFCC components and sub-elements are being fabricated and tested in simulated and/or actual service environments during Phase II of this program.

Jonkouski, J. [Chicago Operations Office, Argonne, IL (United States)

1997-12-31T23:59:59.000Z

172

Fibrous monoliths: Economic ceramic matrix composites from powders [Final report  

SciTech Connect (OSTI)

The project was to develop and perform pilot-scale production of fibrous monolith composites. The principal focus of the program was to develop damage-tolerant, wear-resistant tooling for petroleum drilling applications and generate a basic mechanical properties database on fibrous monolith composites.

Rigali, Mark; Sutaria, Manish; Mulligan, Anthony; Creegan, Peter; Cipriani, Ron

1999-05-26T23:59:59.000Z

173

Modeling the thermal conductivity of fiber-reinforced ceramic composites  

SciTech Connect (OSTI)

A review of models for the prediction of the thermal conductivity of uni-directional fiber-reinforced composites will be presented. The ability of these models to give an accurate prediction of the composite thermal conductivity depends on the amount of information known about the constituent phase properties under the assumption that these properties do not change as a result of processing. Also presented are models that take into account the effects of fiber coatings.

Beecher, S.C.; Dinwiddie, R.B.

1993-06-01T23:59:59.000Z

174

Continuous fiber ceramic composite cladding for commercial water reactor fuel; Final Project  

SciTech Connect (OSTI)

This project is a research effort to develop and demonstrate the feasibility of an improved ceramics-based cladding material for water reactor fuel, which will be significantly more resistant to structural damage during a LOCA accident than the current Zircaloy cladding material. Specifically, the goal of this NERI project is to determine, via engineering type tests, the feasibility of substituting such advanced ceramic materials for the Zircaloy cladding now in use. This report presents the project research and development activities, which included prototype material design, fabrication, characterization, LOCA type of thermal shock testing, and in-reactor irradiation/corrosion testing. The report also presents the technical finding and discussions of results. The technical task were performed in collaboration with four subcontractors: The Advanced Materials Section of McDermott Technology Incorporated (MTI), the Nuclear Reactor Laboratory of Massachusetts Institute of Technology (MTI), Swales Aerospace Inc., and the Thin Film Laboratory of Northwestern University.

Herbert Feinroth

2001-04-30T23:59:59.000Z

175

ADVANCED CERAMIC MATERIALS FOR NEXT-GENERATION NUCLEAR APPLICATIONS  

SciTech Connect (OSTI)

Rising global energy demands coupled with increased environmental concerns point to one solution; they must reduce their dependence on fossil fuels that emit greenhouse gases. As the global community faces the challenge of maintaining sovereign nation security, reducing greenhouse gases, and addressing climate change nuclear power will play a significant and likely growing role. In the US, nuclear energy already provides approximately one-fifth of the electricity used to power factories, offices, homes, and schools with 104 operating nuclear power plants, located at 65 sites in 31 states. Additionally, 19 utilities have applied to the US Nuclear Regulatory Commission (NRC) for construction and operating licenses for 26 new reactors at 17 sites. This planned growth of nuclear power is occurring worldwide and has been termed the 'nuclear renaissance.' As major industrial nations craft their energy future, there are several important factors that must be considered about nuclear energy: (1) it has been proven over the last 40 years to be safe, reliable and affordable (good for Economic Security); (2) its technology and fuel can be domestically produced or obtained from allied nations (good for Energy Security); and (3) it is nearly free of greenhouse gas emissions (good for Environmental Security). Already an important part of worldwide energy security via electricity generation, nuclear energy can also potentially play an important role in industrial processes and supporting the nation's transportation sector. Coal-to-liquid processes, the generation of hydrogen and supporting the growing potential for a greatly increased electric transportation system (i.e. cars and trains) mean that nuclear energy could see dramatic growth in the near future as we seek to meet our growing demand for energy in cleaner, more secure ways. In order to address some of the prominent issues associated with nuclear power generation (i.e., high capital costs, waste management, and proliferation), the worldwide community is working to develop and deploy new nuclear energy systems and advanced fuel cycles. These new nuclear systems address the key challenges and include: (1) extracting the full energy value of the nuclear fuel; (2) creating waste solutions with improved long term safety; (3) minimizing the potential for the misuse of the technology and materials for weapons; (4) continually improving the safety of nuclear energy systems; and (5) keeping the cost of energy affordable.

Marra, J.

2010-09-29T23:59:59.000Z

176

Nondestructive evaluation and characterization of damage and repair to continuous-fiber ceramic composite panels.  

SciTech Connect (OSTI)

Continuous fiber ceramic matrix composites are currently being developed for a variety of high-temperature applications. Because of the high costs of making these components, minor damage incurred during manufacturing or operation must be rewired in order to extend the life of the components. In this study, five ceramic-grade Nicalon{trademark} fiber/SiNC-matrix composite panels were intentionally damaged with a pendulum-type impactor during an impact test. The damaged panels were then repaired at Dow Corning Corporation. Three nondestructive evaluation (NDE) methods were used to study the characteristics of the panels after the damage and again after the panels were repaired. The NDE methods were X-ray radiography, infrared thermal imaging, and air-coupled ultrasound. The results showed that the impact test induced various types of damage in the panels. The NDE data that were obtained by the three NDE methods were correlated with each other.

Sun, J. G.; Petrak, D. R.; Pillai, T. A. K.; Deemer, C.; Ellingson, W. A.

1998-04-01T23:59:59.000Z

177

Mechanical Properties and Oxidation Behaviour of Electroconductive Ceramic Composites  

E-Print Network [OSTI]

obtained by Hot Pressing (HP). In view of the results, the high performance composite grade SiC-HfB2 has for industrial furnaces, aerospace parts... The studies are mainly concerned with the SiC-TiC and SiC- TiB2 pressed at 200 MPa and the crude cylinder was hot isostatically pressed within a silica container at 1850

Paris-Sud XI, Université de

178

Highly conductive electrolyte composites containing glass and ceramic, and method of manufacture  

DOE Patents [OSTI]

An electrolyte composite is manufactured by pressurizing a mixture of sodium ion conductive glass and an ionically conductive compound at between 12,000 and 24,000 pounds per square inch to produce a pellet. The resulting pellet is then sintered at relatively lower temperatures (800--1200 C), for example 1000 C, than are typically required (1400 C) when fabricating single constituent ceramic electrolytes. The resultant composite is 100 percent conductive at 250 C with conductivity values of 2.5 to 4[times]10[sup [minus]2](ohm-cm)[sup [minus]1]. The matrix exhibits chemical stability against sodium for 100 hours at 250 to 300 C. 1 figure.

Hash, M.C.; Bloom, I.D.

1992-10-13T23:59:59.000Z

179

DEVELOPMENT OF CRYSTALLINE CERAMICS FOR IMMOBILIZATION OF ADVANCED FUEL CYCLE REPROCESSING WASTES  

SciTech Connect (OSTI)

The Savannah River National Laboratory (SRNL) is developing crystalline ceramic waste forms to incorporate CS/LN/TM high Mo waste streams consisting of perovskite, hollandite, pyrochlore, zirconolite, and powellite phase assemblages. Simple raw materials, including Al{sub 2}O{sub 3}, CaO, and TiO{sub 2} were combined with simulated waste components to produce multiphase crystalline ceramics. Fiscal Year 2011 (FY11) activities included (i) expanding the compositional range by varying waste loading and fabrication of compositions rich in TiO{sub 2}, (ii) exploring the processing parameters of ceramics produced by the melt and crystallize process, (iii) synthesis and characterization of select individual phases of powellite and hollandite that are the target hosts for radionuclides of Mo, Cs, and Rb, and (iv) evaluating the durability and radiation stability of single and multi-phase ceramic waste forms. Two fabrication methods, including melting and crystallizing, and pressing and sintering, were used with the intent of studying phase evolution under various sintering conditions. An analysis of the XRD and SEM/EDS results indicates that the targeted crystalline phases of the FY11 compositions consisting of pyrochlore, perovskite, hollandite, zirconolite, and powellite were formed by both press and sinter and melt and crystallize processing methods. An evaluation of crystalline phase formation versus melt processing conditions revealed that hollandite, perovskite, zirconolite, and residual TiO{sub 2} phases formed regardless of cooling rate, demonstrating the robust nature of this process for crystalline phase development. The multiphase ceramic composition CSLNTM-06 demonstrated good resistance to proton beam irradiation. Electron irradiation studies on the single phase CaMoO{sub 4} (a component of the multiphase waste form) suggested that this material exhibits stability to 1000 years at anticipated self-irradiation doses (2 x 10{sup 10}-2 x 10{sup 11} Gy), but that its stability may be rate dependent, therefore limiting the activity of the waste for which it can be employed. Overall, these preliminary results indicate good radiation damage tolerance for the crystalline ceramic materials. The PCT results showed that, for all of the waste forms tested, the normalized release values for most of the elements measured, including all of the lanthanides and noble metals, were either very small or below the instrument detection limits. Elevated normalized release values were measured only for Cs, Mo, and Rb. It is difficult to draw further conclusions from these data until a benchmark material is developed for the PCT with this type of waste form. Calcined, simulated CS/LN/TM High Mo waste without additives had relatively low normalized release values for Cs, Mo, and Rb. A review of the chemical composition data for this sample showed that these elements were well retained after the calcination. Therefore, it will be useful to further characterize the calcined material to determine what form these elements are in after calcining. This, along with single phase studies on Cs containing crystal structures such as hollandite, should provide insight into the most ideal phases to incorporate these elements to produce a durable waste form.

Fox, K.; Brinkman, K.

2011-09-22T23:59:59.000Z

180

Oxidation resistant coatings for ceramic matrix composite components  

SciTech Connect (OSTI)

Corrosion resistant Ca{sub 0.6}Mg{sub 0.4}Zr{sub 4}(PO{sub 4}){sub 6} (CMZP) and Ca{sub 0.5}Sr{sub 0.5}Zr{sub 4}(PO{sub 4}){sub 6} (CS-50) coatings for fiber-reinforced SiC-matrix composite heat exchanger tubes have been developed. Aqueous slurries of both oxides were prepared with high solids loading. One coating process consisted of dipping the samples in a slip. A tape casting process has also been created that produced relatively thin and dense coatings covering a large area. A processing technique was developed, utilizing a pre-sintering step, which produced coatings with minimal cracking.

Vaubert, V.M.; Stinton, D.P. [Oak Ridge National Lab., TN (United States); Hirschfeld, D.A. [New Mexico Inst. of Mining and Technology, Socorro, NM (United States). Dept. of Materials and Metallurgical Engineering

1998-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "advanced ceramic composites" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

advanced composite materials: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

advanced composite materials First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 ULTRASONIC...

182

advanced composites technology: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 ADVANCED COMPOSITE MATERIALS TECHNOLOGY FOR ROTORCRAFT Andrew Makeev*, University of Texas at Arlington,...

183

advanced technology composite: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 ADVANCED COMPOSITE MATERIALS TECHNOLOGY FOR ROTORCRAFT Andrew Makeev*, University of Texas at Arlington,...

184

Characterization of material degradation in ceramic matrix composites using infrared reflectance spectroscopy  

SciTech Connect (OSTI)

Ceramic matrix composite materials for thermal protection systems are required to maintain operational performance in extreme thermal and mechanical environments. In-service inspection of materials capable of assessing the degree and extent of damage and degradation will be required to ensure the safety and readiness of future air vehicles. Infrared reflectance spectroscopy is an established material characterization technique capable of extracting information regarding the chemical composition of substances. The viability of this technique as a potentially powerful nondestructive evaluation method capable of monitoring degradation in thermal protection system materials subjected to extreme mechanical and thermal environments is analyzed. Several oxide-based and non-oxide-based ceramic matrix composite materials were stressed to failure in a high temperature environment and subsequently measured using infrared reflectance spectroscopy. Spectral signatures at locations along the length of the samples were compared resulting in distinct and monotonic reflectance peak changes while approaching the fracture point. The chemical significance of the observed signatures and the feasibility of infrared reflectance nondestructive evaluation techniques are discussed.

Cooney, Adam T.; Flattum-Riemers, Richard Y. [Air Force Research Laboratory, Materials and Manufacturing Directorate, NonDestructive Evaluation Branch, Wright-Patterson AFB, OH (United States); Scott, Benjamin J. [Universal Technology Corporation, Dayton, OH (United States)

2011-06-23T23:59:59.000Z

185

Continuous Fiber Ceramic Composite (CFCC) Program. Inventory of federally funded CFCC R&D projects  

SciTech Connect (OSTI)

Continuous Fiber Ceramic Composites (CFCC) are a new class of materials that are lighter, stronger, more corrosion resistant, and capable of performing at elevated temperatures. This new type of material offers the potential to meet the demands of a variety of industrial, military, and aerospace applications. The Department of Energy Office of Industrial Technologies (OIT) has a new program on CFCCs for industrial applications and this program has requested an inventory of all federal projects on CFCCs that relate to their new program. The purpose of this project is to identify all other ongoing CFCC research to avoid redundancy in the OIT Program. The inventory will be used as a basis for coordinating with the other ongoing ceramic composite projects. The inventory is divided into two main parts. The first part is concerned with CFCC supporting technologies projects and is organized by the categories listed below. (1) Composite Design; (2) Materials Characterization; (3) Test Methods; (4) Non-Destructive Evaluation; (5) Environmental Effects; (6) Mechanical Properties; (7) Database Life Prediction; (8) Fracture/Damage; and (9) Joining. The second part has information on component development, fabrication, and fiber-related projects.

Richlen, S. [USDOE Assistant Secretary for Energy Efficiency and Renewable Energy, Washington, DC (United States). Office of Industrial Technologies; Caton, G.M.; Karnitz, M.A.; Cox, T.D. [Oak Ridge National Lab., TN (United States); Hong, W. [Institute for Defense Analyses, Alexandria, VA (United States)

1993-05-01T23:59:59.000Z

186

ENERGY EFFICIENCY CHALLENGES ADDRESSED THROUGH THE USE OF ADVANCED REFRACTORY CERAMIC MATERIALS  

SciTech Connect (OSTI)

Refractory ceramics can play a critical role in improving the energy efficiency of traditional industrial processes through increased furnace efficiency brought about by the employment of novel refractory systems and techniques. Examples of advances in refractory materials related to aluminum, gasification, glass, and lime are highlighted. Energy savings are realized based on reduction of chemical reactions, elimination of mechanical degradation caused by the service environment, reduction of temperature limitations of materials, and elimination of costly installation and repair needs. Key results of projects resulting from US Department of Energy (DOE) funded research programs are discussed with emphasis on applicability of these results to high temperature furnace applications and needed research directions for the future.

Hemrick, James Gordon [ORNL

2014-01-01T23:59:59.000Z

187

Development of a compound for low temperature joining of SiC ceramics and CFCC composites  

SciTech Connect (OSTI)

This investigation was driven by the need for a robust, practical method to join continuous fiber-reinforced ceramic composite (CFCC) materials composed of SiC fibers in a SiC matrix (SiC/SiC). A new filler compound composition resulted from this research which is composed primarily of a silicon-acetylene ceramic precursor polymer blended with fine alloy and elemental powders. Joint formation relies on reaction of the powders with the products of the polymer pyrolysis reaction and the CFCC on continuous heating from room temperature to the curing temperature. The joint can be heated and cured either in an inert or air atmosphere furnace or in air upon heating with a propane torch to a maximum curing temperature of about 1200{degrees}C. This curing temperature is effective for joint formation while preventing degradation of the SiC fibers in the CFCC material and permitting field joining of SiC CFCC parts with an open flame torch. The joining compound demonstrated good wetting and joint filling characteristics. Mechanical property testing revealed a room temperature bend strength of 50 to 100MPa (7 to 14ksi), depending on care in joint preparation. There was a tendency for partial SiC fiber pullout as the crack propagation path wandered in and out of the joint material during fracture, adding toughness. Preliminary mechanical tests of joined samples, after exposure to high temperature (1100{degrees}C) ambient air for 100 hours. indicated excellent retention of strength.

Anderson, I.E.; Ijadi-Maghsoodi, S.; Uenal, O. [Ames Lab., IA (United States)] [and others

1997-11-01T23:59:59.000Z

188

Ferroelectric polymer-ceramic composite thick films for energy storage applications  

SciTech Connect (OSTI)

We have successfully fabricated large area free standing polyvinylidene fluoride -Pb(Zr{sub 0.52}Ti{sub 0.48})O{sub 3} (PVDF-PZT) ferroelectric polymer-ceramic composite (wt% 80–20, respectively) thick films with an average diameter (d) ?0.1 meter and thickness (t) ?50 ?m. Inclusion of PZT in PVDF matrix significantly enhanced dielectric constant (from 10 to 25 at 5 kHz) and energy storage capacity (from 11 to 14 J/cm{sup 3}, using polarization loops), respectively, and almost similar leakage current and mechanical strength. Microstructural analysis revealed the presence of ? and ? crystalline phases and homogeneous distribution of PZT crystals in PVDF matrix. It was also found that apart from the microcrystals, well defined naturally developed PZT nanocrystals were embedded in PVDF matrix. The observed energy density indicates immense potential in PVDF-PZT composites for possible applications as green energy and power density electronic elements.

Singh, Paritosh; Borkar, Hitesh; Singh, B. P.; Singh, V. N.; Kumar, Ashok, E-mail: ashok553@nplindia.org [CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi 110012 (India)

2014-08-15T23:59:59.000Z

189

Highly conductive electrolyte composites containing glass and ceramic, and method of manufacture  

DOE Patents [OSTI]

An electrolyte composite is manufactured by pressurizing a mixture of sodium ion conductive glass and an ionically conductive compound at between 12,000 and 24,000 pounds per square inch to produce a pellet. The resulting pellet is then sintered at relatively lower temperatures (800.degree. C.-1200.degree. C.), for example 1000.degree. C., than are typically required (1400.degree. C.) when fabricating single constituent ceramic electrolytes. The resultant composite is 100 percent conductive at 250.degree. C. with conductivity values of 2.5 to 4.times.10.sup.-2 (ohm-cm).sup.-1. The matrix exhibits chemical stability against sodium for 100 hours at 250.degree. to 300.degree. C.

Hash, Mark C. (Joliet, IL); Bloom, Ira D. (Bolingbrook, IL)

1992-01-01T23:59:59.000Z

190

Topical report to Morgantown Energy Technology Center for the interfacial coatings for ceramic-matrix composites  

SciTech Connect (OSTI)

This report summarizes the task conducted to examine various activities on interface development for ceramic-matrix composites (CMCs) intended for high-temperature applications. While several articles have been published on the subject of CMC interfaces, the purpose of this report is to describe the various ongoing efforts on interface concepts, material selection, and issues related to processing methods employed for developing interface coatings. The most exciting and new development in the field is the discovery of monazite as a potential interface material for mullite- and alumina-based composites. Monazite offers two critical properties to the CMC system; a weakly bonded layer due to its non-wetting behavior and chemical compatibility with both alumina and mullite up to very high temperatures (> 1,600 C). A description of the Department of Energy-related activities and some thoughts on processing issues, interface testing, and effects of processing on fiber strength are given.

NONE

1997-01-09T23:59:59.000Z

191

Continuous fiber ceramic composite. Phase I final report, April 1992--April 1993  

SciTech Connect (OSTI)

Babcock and Wilcox assembled a team to develop the Continuous Fiber Ceramic Composite (CFCC) processing technology, identify the industrial applications, generate design and life prediction software, and to begin the necessary steps leading to full commercialization of CFCC components. Following is a summary of Phase I activities on this program. B&W has selected an oxide-oxide composite system for development and optimization in this program. This selection was based on the results of exposure tests in combustion environments typical of the boiler and heat exchanger applications. Aluminum oxide fiber is the selected reinforcement, and both aluminum oxide and zirconium oxide matrices were selected, based on their superior resistance to chemical attack in hostile industrial service.

Goettler, R.W.

1995-04-01T23:59:59.000Z

192

Recent advances and issues in development of silicon carbide composites for fusion applications  

SciTech Connect (OSTI)

Radiation-resistant advanced silicon carbide composites (SiC/SiC) have been developed as a promising candidate of the high-temperature operating advanced fusion DEMO reactor. With the completion of the “proof-of-principle” phase in development of “nuclear-grade” SiC/SiC, the R&D on SiC/SiC is shifting toward the more pragmatic phase, i.e., industrialization of component manufactures and data-basing. In this paper, recent advances and issues in 1) development of component fabrication technology including joining and functional coating, e.g., a tungsten overcoat as a plasma facing barrier, 2) recent updates in characterization of non-irradiated properties, e.g., strength anisotropy and chemical compatibility with solid lithium-based ceramics and lead-lithium liquid metal breeders, and 3) irradiation effects were specifically reviewed. Importantly high-temperature neutron irradiation effects on microstructural evolution, thermal and electrical conductivities and mechanical properties including the fiber/matrix interfacial strength were specified under various irradiation conditions, indicating seemingly very minor influence on the composite performance in the design temperature range.

Nozawa, T.; Hinoki, Tetsuya; Hasegawa, Akira; Kohyama, Akira; Katoh, Yutai; Snead, Lance L.; Henager, Charles H.; Hegeman, Hans

2009-04-30T23:59:59.000Z

193

Design of a continuous fiber ceramic composite heat exchanger for high-temperature, high-pressure applications  

SciTech Connect (OSTI)

A conceptual design of a continuous fiber ceramic composite (CFCC) heat exchanger for high-temperature, high-pressure applications is presented. The CFCC materials under consideration are SiC reinforced with SiC fibers manufactured using the continuous vapor infiltration process and alumina reinforced with SiC or alumina fibers manufactured using the directed metal oxidation process. These composite materials are highly resistant to high-temperature corrosive environment and possess a greater creep strength than metallic materials. Heat exchangers constructed of CFCC material may be utilized for high-temperature, high-pressure applications such as air/gas heaters in advanced energy systems and high-temperature energy recovery systems. This paper presents a design of a gas-to-air CFCC heat exchanger for the high temperature advanced furnace (HITAF) in the high-performance power system (HIPPS). The 1.38 MPa (200 psia) air is heated from 760 C (1,400 F) to 982 C (1,800 F) using the combustion products at 1,650 C (3,000 F). The heat exchanger is of a cross-parallel/counter flow type in which the tube-side air flow makes a combined parallel and counter flow arrangement with a cross-flowing combustion gas in such a way that the maximum CFCC tube temperature will not exceed a 1,260 C (2,300 F) design limit. The main heat transfer mechanism from the external hot gas to the tube-side air is that of gaseous radiation for the first few rows of the tubes, followed by convective heat transfer across the remainder of the tube bundle. The design characteristics of this high-temperature, high-pressure CFCC heat exchanger with supporting thermal, flow, structural, and vibrational analyses are presented in detail in the paper.

Cho, S.M.; Seltzer, A.H.; Narayanan, T.V. [Foster Wheeler Development Corp., Livingston, NJ (United States); Shah, A.C.; Weddell, J.K. [DuPont Lanxide Composites Inc., Newark, DE (United States)

1996-12-31T23:59:59.000Z

194

Seminar Title: Additive Manufacturing Advanced Manufacturing of Polymer and Composite Components  

E-Print Network [OSTI]

Seminar Title: Additive Manufacturing ­ Advanced Manufacturing of Polymer and Composite Components Functionally Integrated Composite Structures, Augsburg, Germany ME Faculty Candidate Abstract: Additive Manufacturing ­ Advanced Manufacturing of Polymer and Composite Components Additive manufacturing technologies

Wisconsin at Madison, University of

195

Fiber coatings and the fracture behavior of a continuous fiber ceramic composite  

SciTech Connect (OSTI)

Continuous fiber reinforced ceramic composites (CFCC) are being recognized as necessary for high-temperature structural applications. For instance, the applications of SiC/SiC composites in elevated-temperature structures, such as first wall, and high heat flux surfaces in fusion reactors, as well as in combustors and boiler components in power generation systems, have drawn considerable attention. In the present study, Nicalon{sup {reg_sign}} plane-weave fiber reinforced SiC matrix composites have been fabricated by forced chemical vapor infiltration (FCVI) methods. The influence of fiber/matrix interface coating thickness on the fracture behavior of the continuous fiber reinforced SiC composites has been investigated. Experimental results indicate that fiber coating thickness significantly alters the fracture behavior of SiC composites. The fracture strength exhibits a maximum as the coating thickness increases. A mechanistic understanding of the fracture behavior is provided. Furthermore, a theoretical model is formulated to provide a better understanding of the effects of coating thickness on fracture behavior. The predicted fracture behavior was found to be in good agreement with the experimental results.

Miller, J.H.; Lowden, R.A. [Oak Ridge National Lab., TN (United States); Liaw, P.K. [Univ. of Knoxville, TN (United States)

1995-12-31T23:59:59.000Z

196

Advanced Composite Materials | GE Global Research  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAbout the Building TechnologiesS1!4TCombustion Advanced

197

Micromechanical Damage Models for Continuous Fiber Reinforced Composite Materials  

E-Print Network [OSTI]

of metal and ceramic-matrix composites, Acta Metallurgica etMMCs) and ceramic matrix composites (CMCs). In general, PMCsPolymer Matrix Composite Ceramic Matrix Composite Composite

Wu, Yi

2013-01-01T23:59:59.000Z

198

Micromechanical Damage Models for Continuous Fiber Reinforced Composite Materials  

E-Print Network [OSTI]

strength of metal and ceramic-matrix composites, Actacomposites (MMCs) and ceramic matrix composites (CMCs). InPolymer Matrix Composite Ceramic Matrix Composite Composite

Wu, Yi

2013-01-01T23:59:59.000Z

199

Thermal imaging and air-coupled ultrasound characterization of a continuous-fiber ceramic composite panels.  

SciTech Connect (OSTI)

SYLRAMIC{trademark} continuous fiber ceramic-matrix composites (Nicalon{trademark} fiber/SiNC matrix) were fabricated by Dow Corning Corporation with the polymer-impregnation and pyrolysis (PIP) process. The composite microstructure and its uniformity, and the completeness of infiltration during processing were studied as a function of number of PIP cycles. Two nondestructive evaluation (NDE) methods, i.e., infrared thermal imaging and air-coupled ultrasound (UT), were used to investigate flat composite panels of two thicknesses and various sizes. The thermal imaging method provided two-dimensional (2D) images of through-thickness thermal diffusivity distributions, and the air-coupled UT method provided 2D images of through-thickness ultrasonic transmission of the panel components. Results from both types of NDEs were compared at various PIP cycles during fabrication of the composites. A delaminated region was clearly detected and its progressive repair was monitored during processing. The NDE data were also correlated to results obtained from destructive characterization.

Sun, J. G.; Easler, T. E.; Szweda, A.; Pillai, T. A. K.; Deemer, C.; Ellingson, W. A.

1998-04-01T23:59:59.000Z

200

Evaluation of the interfacial mechanical properties in fiber-reinforced ceramic composites  

SciTech Connect (OSTI)

The present study examined the application of a micro-indentation technique to the measurement of interfacial properties in fiber reinforced ceramic composites. Specific fiber/matrix systems included SiC/glass, SiC/macro-defect-free (MDF) cement, SiC/SiC, and mullite/glass. The effect of fiber coatings upon the interfacial properties was also investigated. These properties, which included the debond strength, interfacial shear stress, and residual axial fiber stress, were evaluated by measuring the force-displacement curves generated during load-unload cycles. Estimates of these three stress values were obtained by matching the experimental force-displacement curves with data predicted from an existing model. In general the SiC/glass composites exhibited the lowest values of the interfacial shear and debond stresses. The sliding characteristics of the SiC/MDF cement and SiC/SiC composites were strongly influenced by the residual axial stress and the nature of the fiber coating. In the case of the mullite/glass composite, the high values of the interfacial shear and debond stresses reduced the measurement sensitivity, thereby increasing the uncertainty in the estimates of the interfacial properties. 17 refs, 6 figs, 1 tab.

Ferber, M.K.; Wereszczak, A.A.; Riester, L.; Lowden, R.A. [Oak Ridge National Lab., TN (United States); Chawla, K.K. [New Mexico Inst. of Mining and Technology, Socorro, NM (United States)

1993-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "advanced ceramic composites" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Ceramic Technology Project semiannual progress report for October 1991--March 1992  

SciTech Connect (OSTI)

Objective is to develop the industrial technology base required for reliable ceramics for application in advanced automotive heat engines. Focus is on structural ceramics for advanced gas turbine and diesel engines, ceramic bearings and attachments, and ceramic coatings for thermal barrier and wear applications in these engines. The work is organized into the following elements: materials and processing (monolithics [SiC, SiN], ceramic composites, thermal and wear coatings, joining), materials design methodology, data base and life prediction (structural qualification, time-dependent behavior, environmental effects, fracture mechanics, NDE), and technology transfer. Individual abstracts were prepared for the individual contributions.

Not Available

1992-09-01T23:59:59.000Z

202

Titanium diboride-chromium diboride-yttrium titanium oxide ceramic composition and a process for making the same  

DOE Patents [OSTI]

A ceramic composition is described. The ceramic composition consists essentially of from about 84 to 96 w/o titanium diboride, from about 1 to 9 w/o chromium diboride, and from about 3 to about 15 w/o yttrium-titanium-oxide. A method of making the ceramic composition is also described. The method of making the ceramic composition comprises the following steps: Step 1--A consolidated body containing stoichiometric quantities of titanium diboride and chromium diboride is provided. Step 2--The consolidated body is enclosed in and in contact with a thermally insulated package of yttria granules having a thickness of at least 0.5 inches. Step 3--The consolidated body enclosed in the thermally insulated package of yttria granules is heated in a microwave oven with microwave energy to a temperature equal to or greater than 1,900 degrees centigrade to sinter and uniformly disperse yttria particles having a size range from about 1 to about 12 microns throughout the consolidated body forming a densified body consisting essentially of titanium diboride, chromium diboride, and yttrium-titanium-oxide. The resulting densified body has enhanced fracture toughness and hardness.

Holcombe, Cressie E. (Knoxville, TN); Dykes, Norman L. (Oak Ridge, TN)

1991-01-01T23:59:59.000Z

203

Ceramic superconductor/metal composite materials employing the superconducting proximity effect  

DOE Patents [OSTI]

Superconducting composite materials having particles of superconducting material disposed in a metal matrix material with a high electron-boson coupling coefficient (.lambda.). The superconducting particles can comprise any type of superconductor including Laves phase materials, Chevrel phase materials, A15 compounds, and perovskite cuprate ceramics. The particles preferably have dimensions of about 10-500 nanometers. The particles preferably have dimensions larger than the superconducting coherence length of the superconducting material. The metal matrix material has a .lambda. greater than 0.2, preferably the .lambda. is much higher than 0.2. The metal matrix material is a good proximity superconductor due to its high .lambda.. When cooled, the superconductor particles cause the metal matrix material to become superconducting due to the proximity effect. In cases where the particles and the metal matrix material are chemically incompatible (i.e., reactive in a way that destroys superconductivity), the particles are provided with a thin protective metal coating. The coating is chemically compatible with the particles and metal matrix material. High Temperature Superconducting (HTS) cuprate ceramic particles are reactive and therefore require a coating of a noble metal resistant to oxidation (e.g., silver, gold). The proximity effect extends through the metal coating. With certain superconductors, non-noble metals can be used for the coating.

Holcomb, Matthew J. (Manhattan Beach, CA)

2002-01-01T23:59:59.000Z

204

Radiation-tolerant joining technologies for silicon carbide ceramics and composites  

SciTech Connect (OSTI)

Silicon carbide (SiC) for nuclear structural applications, whether in the monolithic ceramic or composite form, will require a robust joining technology capable of withstanding the harsh nuclear environment. This paper presents significant progress made towards identifying and processing irradiation-tolerant joining methods for nuclear-grade SiC. In doing so, a standardized methodology for carrying out joint testing has been established consistent with the small volume samples mandated by neutron irradiation testing. Candidate joining technologies were limited to those that provide low induced radioactivity and included titanium diffusion bonding, Ti–Si–C MAX-phase joining, calcia–alumina glass–ceramic joining, and transient eutectic-phase SiC joining. Samples of these joints were irradiated in the Oak Ridge National Laboratory High Flux Isotope Reactor at 500 or 800 ?C, and their microstructure and mechanical properties were compared to pre-irradiation conditions. Within the limitations of statistics, all joining methodologies presented retained their joint mechanical strength to 3 dpa at 500 ?C, thus indicating the first results obtained on irradiation-stable SiC joints. Under the more aggressive irradiation conditions (800 ?C, 5 dpa), some joint materials exhibited significant irradiation-induced microstructural evolution; however, the effect of irradiation on joint strength appeared rather limited.

Katoh, Yutai; Snead, Lance L.; Cheng, Ting; Shih, Chunghao; Lewis, W. Daniel; Koyanagi, Takaaki; Hinoki, Tetsuya; Henager, Charles H.; Ferraris, Monica

2014-05-01T23:59:59.000Z

205

Thermal imaging measurement of lateral thermal diffusivity in continuous fiber ceramic composites  

SciTech Connect (OSTI)

Infrared thermal imaging has become a common technique for nondestructive evaluation and measurement of thermal properties in ceramic specimens. Flash thermal imaging can be used to determine two-dimensional through-thickness thermal diffusivity in a planar specimen. In this study, the authors extended the method to determine lateral, or transverse, thermal diffusivity in the specimen. During the flash thermal imaging test, pulsed heat energy is applied to a specimen's back surface, which is partially shielded, and the change of temperature distribution on the front surface is monitored by an infrared thermal imaging system. The temperature distribution represents the effect of both the normal heat transfer through the specimen's thickness and the lateral heat transfer through the interface between the shielded and unshielded back-surface regions. Those temperature distributions are then fitted with a theoretical solution of the heat transfer process to determine the lateral thermal diffusivity at the interface. This technique has been applied to measure lateral thermal diffusivity in a steel plate and a continuous fiber ceramic composite specimen.

Sun, J. G.; Deemer, C.; Ellingson, W. A.

2000-02-18T23:59:59.000Z

206

Fibrous ceramic monoliths made from multi-phase ceramic filaments  

DOE Patents [OSTI]

A method for producing composite ceramic material is provided wherein a core ceramic structure is produced and simultaneously enveloped with a sleeve of similar material.

Goretta, Kenneth C. (Downers Grove, IL); Singh, Dileep (Naperville, IL); Polzin, Bryant J. (Mundelein, IL); Cruse, Terry (Lisle, IL); Picciolo, John J. (Lockport, IL)

2008-11-18T23:59:59.000Z

207

Analytical modeling in support of the development of fiber reinforced ceramic composite materials for re-heater burners  

SciTech Connect (OSTI)

Development of Continuous Fiber reinforced Ceramic Composite (CFCC) materials is a process of identifying components which will benefit from CFCC properties, and defining appropriate composite constructions which will provide materials which will meet the structural and thermal requirements of the application. Materials Sciences Corporation (MSC) has been providing analytical support to Textron Specialty Materials in the development of re-heated tubes for metal reheating furnaces. As part of this support, a study has been made of the sensitivity of composite properties to fiber orientation as well as a number of matrix properties which control the stress-strain behavior of the composite.

Kibler, J.J. [Materials Sciences Corp., Fort Washington, PA (United States); DiPietro, S.G. [Textron Specialty Materials, Lowell, MA (United States)

1995-10-01T23:59:59.000Z

208

Prototype Development of Remote Operated Hot Uniaxial Press (ROHUP) to Fabricate Advanced Tc-99 Bearing Ceramic Waste Forms - 13381  

SciTech Connect (OSTI)

The objective of this senior student project is to design and build a prototype construction of a machine that simultaneously provides the proper pressure and temperature parameters to sinter ceramic powders in-situ to create pellets of rather high densities of above 90% (theoretical). This ROHUP (Remote Operated Hot Uniaxial Press) device is designed specifically to fabricate advanced ceramic Tc-99 bearing waste forms and therefore radiological barriers have been included in the system. The HUP features electronic control and feedback systems to set and monitor pressure, load, and temperature parameters. This device operates wirelessly via portable computer using Bluetooth{sup R} technology. The HUP device is designed to fit in a standard atmosphere controlled glove box to further allow sintering under inert conditions (e.g. under Ar, He, N{sub 2}). This will further allow utilizing this HUP for other potential applications, including radioactive samples, novel ceramic waste forms, advanced oxide fuels, air-sensitive samples, metallic systems, advanced powder metallurgy, diffusion experiments and more. (authors)

Alaniz, Ariana J.; Delgado, Luc R.; Werbick, Brett M. [University of Nevada - Las Vegas, Howard R. Hughes College of Engineering, 4505 S. Maryland Parkway, Box 454009, Las Vegas, NV 89154-4009 (United States)] [University of Nevada - Las Vegas, Howard R. Hughes College of Engineering, 4505 S. Maryland Parkway, Box 454009, Las Vegas, NV 89154-4009 (United States); Hartmann, Thomas [University of Nevada - Las Vegas, Harry Reid Canter, 4505 S. Maryland Parkway, Box 454009, Las Vegas, NV 89154-4009 (United States)] [University of Nevada - Las Vegas, Harry Reid Canter, 4505 S. Maryland Parkway, Box 454009, Las Vegas, NV 89154-4009 (United States)

2013-07-01T23:59:59.000Z

209

E-Print Network 3.0 - advanced ceramic hot-gas Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

nitride and silicon carbide ceramics exposed to a representative ... Source: Pint, Bruce A. - Materials Science & Technology Division, Oak Ridge National Laboratory...

210

E-Print Network 3.0 - advanced ceramic tube Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

and Ramot Ltd. Tel... be used to drill into concrete, silicon, ceramic, rocks, glass, plastic, and even wood. Hole diameters Source: Jerby, Eli - Department of Electrical...

211

The Prediction and Simulation for the Mechanical Properties of Ceramic-Based Composites Reinforced with Nano-Micro Particles  

SciTech Connect (OSTI)

The global-local homogenization method with precise period boundary conditions is applied to predict and simulate the mechanical properties of ceramic composites reinforced by spherical nano-micro particles with enwrapping and nesting arrays. The numerical simulation is performed with different size ratios of nano-micro particles, and different configurations for representative volume element. The results show that the low radius ratios of nano-micro particles produce a larger effective Young's modulus for its more uniform dispersion, and the hexagon RVE with nesting array can make an overestimation for effective elastic modulus of ceramic composites, and the interfacial damage between nano-microscopic particles and matrix degenerates the effective elastic modulus. It shows in this paper that it is significant to improve the mechanical properties of ceramic materials by mixing some nano- and micro-particles into the matrix with good designed array methods from the viewpoints of nano-microscopic crystal structure, and a rational interfacial damage model should be further proposed to investigate the toughening mechanism of ceramic-composites reinforced with nano-micro particles.

Luo Dongmei; Hu Jinshan; Yang Hong [Environment and Civil Engineering School, Foshan University, Foshan, 528000 (China); Zhou Yinglong [Department of Mechatronics Engineering, Foshan University, Foshan 528000 (China)

2010-05-21T23:59:59.000Z

212

E-Print Network 3.0 - advanced polymer composites Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

chemistry to synthesize conjugated polymer composites for use in photovoltaic and optoelectronic devices... lighting and energy solutions, advanced communication products, ......

213

E-Print Network 3.0 - advanced composite polymer Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

chemistry to synthesize conjugated polymer composites for use in photovoltaic and optoelectronic devices... lighting and energy solutions, advanced communication products, ......

214

Effects of neutron irradiation on thermal conductivity of SiC-based composites and monolithic ceramics  

SciTech Connect (OSTI)

A variety of SiC-based composites and monolithic ceramics were characterized by measuring their thermal diffusivity in the unirradiated, thermal annealed, and irradiated conditions over the temperature range 400 to 1,000 C. The irradiation was conducted in the EBR-II to doses of 33 and 43 dpa-SiC (185 EFPD) at a nominal temperature of 1,000 C. The annealed specimens were held at 1,010 C for 165 days to approximately duplicate the thermal exposure of the irradiated specimens. Thermal diffusivity was measured using the laser flash method, and was converted to thermal conductivity using density data and calculated specific heat values. Exposure to the 165 day anneal did not appreciably degrade the conductivity of the monolithic or particulate-reinforced composites, but the conductivity of the fiber-reinforced composites was slightly degraded. The crystalline SiC-based materials tested in this study exhibited thermal conductivity degradation of irradiation, presumably caused by the presence of irradiation-induced defects. Irradiation-induced conductivity degradation was greater at lower temperatures, and was typically more pronounced for materials with higher unirradiated conductivity. Annealing the irradiated specimens for one hour at 150 C above the irradiation temperature produced an increase in thermal conductivity, which is likely the result of interstitial-vacancy pair recombination. Multiple post-irradiation anneals on CVD {beta}-SiC indicated that a portion of the irradiation-induced damage was permanent. A possible explanation for this phenomenon was the formation of stable dislocation loops at the high irradiation temperature and/or high dose that prevented subsequent interstitial/vacancy recombination.

Senor, D.J.; Youngblood, G.E. [Pacific Northwest National Lab., Richland, WA (United States); Moore, C.E. [Auburn Univ., AL (United States); Trimble, D.J. [Westinghouse Hanford Co., Richland, WA (United States); Woods, J.J. [Lockheed Martin, Schenectady, NY (United States)

1996-06-01T23:59:59.000Z

215

Effects of neutron irradiation on thermal conductivity of SiC-based composites and monolithic ceramics  

SciTech Connect (OSTI)

A variety of SiC-based composites and monolithic ceramics were characterized by measuring their thermal diffusivity in the unirradiated, thermal annealed, and irradiated conditions over the temperature range 400 to 1,000 C. The irradiation was conducted in the EBR-II to doses of 33 and 43 dpa-SiC (185 EFPD) at a nominal temperature of 1,000 C. The annealed specimens were held at 1,010 C for 165 days to approximately duplicate the thermal exposure of the irradiated specimens. Thermal diffusivity was measured using the laser flash method, and was converted to thermal conductivity using density data and calculated specific heat values. Exposure to the 165 day anneal did not appreciably degrade the conductivity of the monolithic or particulate-reinforced composites, but the conductivity of the fiber-reinforced composites was slightly degraded. The crystalline SiC-based materials tested in this study exhibited thermal conductivity degradation after irradiation, presumably caused by the presence of irradiation-induced defects. Irradiation-induced conductivity degradation was greater at lower temperatures, and was typically more pronounced for materials with higher unirradiated conductivity. Annealing the irradiated specimens for one hour at 150 C above the irradiation temperature produced an increase in thermal conductivity, which is likely the result of interstitial-vacancy pair recombination. Multiple post-irradiation anneals on CVD {beta}-SiC indicated that a portion of the irradiation-induced damage was permanent. A possible explanation for this phenomenon was the formation of stable dislocation loops at the high irradiation temperature and/or high dose that prevented subsequent interstitial/vacancy recombination.

Senor, D.J.; Youngblood, G.E. [Pacific Northwest National Lab., Richland, WA (United States); Moore, C.E. [Auburn Univ., AL (United States); Trimble, D.J. [Westinghouse Hanford Co., Richland, WA (United States); Woods, J.J. [Lockheed Martin, Schenectady, NY (United States)

1997-05-01T23:59:59.000Z

216

Corrosion of SiC and oxide-composite ceramics by a simulated steam-reformer atmosphere  

SciTech Connect (OSTI)

To achieve higher process efficiency by using pressurized reactants and/or heat transfer fluids, the US DOE is promoting development of high-pressure heat exchanger systems under cost-sharing agreements with industrial contractors. The steam reformer would contain more than 600 tubes. Because the combination of high temperature and pressure differential of 12.7 kg/cm{sup 2} (180 psig) across the tube wall is too severe for metallic tubes, ceramic materials are being considered for reformer tubes. Their use is expected to increase the efficiency of steam reformers by about 19%. At ORNL, four SiC ceramics, a SiC-TiB{sub 2} composite, a Si{sub 3}N{sub 4}-bonded SiC ceramic, and two alumina-matrix composites were selected as candidate materials for heat exchanger/steam-reformer tubes. These commercially available materials were exposed to a simulated steam-reformer atmosphere for up to 2000 h at 1260{degrees}C to assess their corrosion behavior and the effect of the exposure on their flexure strength (in air) at 20 and 1260{degrees}C. The approximate partial pressures of the constituents of the gas mixture at 1 atm total pressure were 0.54 H{sub 2}, 0.13 CO, 0.03 CO{sub 2}m 0.004 CH{sub 4}, and 0.30 H{sub 2}O. All but one material had net weight gains during the exposure test. The flexure strengths of the SiC and Si{sub 3}N{sub 4} ceramics and the SiC-TiB{sub 2} composite at 20 and 1260{degrees}C were not changed significantly by corrosion. The strengths of the alumina-matrix composites were decreased by corrosion; however, the strength of one of these (reinforced with SiC whiskers) was still higher than that of any other material after 500 h. The other alumina composite (containing SiC particles) exhibited the largest strength decrease of any material. The strength retention of the SiC ceramics and the SiC-TiB{sub 2} composite and the strength loss of the composites were associated with surface layers caused by corrosion. 12 refs., 12 figs., 4 tabs.

Federer, J.I.; Kim, H.E.; Moorhead, A.J.

1991-09-01T23:59:59.000Z

217

E-Print Network 3.0 - advanced technical ceramics Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Converting Natural Gas to H2 & Syngas for Liquid... ) Fossil-Based Hydrogen Production Praxair Praxair SNL TIAX Integrated Ceramic Membrane System for H2 Source: DOE Office of...

218

ADVANCED COMPOSITE MATERIALS TECHNOLOGY FOR ROTORCRAFT Andrew Makeev*, University of Texas at Arlington, Arlington, Texas, USA  

E-Print Network [OSTI]

ADVANCED COMPOSITE MATERIALS TECHNOLOGY FOR ROTORCRAFT Andrew Makeev*, University of Texas, Patz Materials & Technologies, Benicia, CA, USA Abstract Composite materials are increasingly used. In polymer-matrix composite structures, matrix-dominated failures impose severe limitations on structural

Texas at Arlington, University of

219

Giant dielectric response in Pb,,Zr,Ti...O3Pb2Ru2O6.5 all-ceramic percolative composite  

E-Print Network [OSTI]

Giant dielectric response in Pb,,Zr,Ti...O3­Pb2Ru2O6.5 all-ceramic percolative composite Vid Bobnar response of a composite comprising a conductive filler embedded in a dielectric matrix--the effective­9 and inorganic composites comprising metal particles dis- persed in a dielectric matrix10­14 have been developed

Bobnar, Vid

220

Technical progress report during Phase 1 of the continuous fiber ceramic composites program  

SciTech Connect (OSTI)

United States industry has a critical need for materials that are lightweight, strong, tough, corrosion resistant and capable of performing at high temperatures; such materials will enable substantial increase in energy efficiency and reduction in emissions of pollutants. Continuous fiber ceramic composites (CFCCs) are an emerging class of materials which have the potential for the desired combination of properties to meet the industrial needs. A $10 billion annual market has been estimated for CFCC products by the year 2010, which equates to over 100,000 industrial sector jobs. The CFCC program began in the spring of 1992 as a three-phase 10-year effort to assess potential applications of CFCC materials, develop the necessary supporting technologies to design, analyze and test CFCC materials, conduct materials and process development guided by the applications assessment input, fabricate test samples and representative components to evaluate CFCC material capabilities under application conditions, and analyze scaleability and manufacturability plus demonstrate pilot-scale production engineering. DOE awarded 10 Phase I cooperative agreements to industry-lead teams plus identified generic supporting technology projects. This document highlights the broad progress and accomplishments on these contracts and support technology projects during Phase I.

Richerson, D.W.

1994-03-15T23:59:59.000Z

Note: This page contains sample records for the topic "advanced ceramic composites" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Development and characterization of Textron continuous fiber ceramic composite hot gas filter materials. Final report, September 30, 1994--October 31, 1997  

SciTech Connect (OSTI)

Uncertainties about the long-term ability of monolithic ceramics to survive in the IGCC or PFBC hot gas filter environment led DOE/METC to consider the merits of using continuous fiber reinforced ceramic composites (CFCCs) as potential next-generation high temperature filter elements. This seems to be a logical strategy to pursue in light of the fact that properly-engineered CFCC materials have shown much-improved damage tolerance and thermal shock behavior as compared to existing monolithic ceramic materials. Textron`s Advanced Hot Gas Filter Development Program was intended to be a two year, two phase program which transitioned developmental materials R and D into prototype filter element fabrication. The first phase was to demonstrate the technical feasibility of fabricating CFCC hot gas filter elements which could meet the pressure drop specifications of less than ten inches of water (iwg) at a face velocity of ten feet per minute (fpm), while showing sufficient integrity to survive normal mechanical loads and adequate environmental resistance to steam/alkali corrosion conditions at a temperature of approximately 870 C (1600 F). The primary objective of the second phase of the program was to scale up fabrication methods developed in Phase 1 to produce full-scale CFCC candle filters for validation testing. Textron encountered significant process-related and technical difficulties in merely meeting the program permeability specifications, and much effort was expended in showing that this could indeed be achieved. Thus, by the time the Phase 1 program was completed, expenditure of program funds precluded continuing on with Phase 2, and Textron elected to terminate their program after Phase 1. This allowed Textron to be able to focus technical and commercialization efforts on their largely successful DOE CFCC Program.

DiPietro, S.G.; Alvin, M.A.

1997-12-31T23:59:59.000Z

222

Interfacial coatings for ceramic-matrix composites -- Volume 2. Final report  

SciTech Connect (OSTI)

This report summarizes the task conducted to examine various activities on interface development for ceramic-matrix composites (CMCs) intended for high-temperature applications. While several articles have been published on the subject of CMC interfaces, the purpose of this report is to describe the various ongoing efforts on interface concepts, material selection, and issues related to processing methods employed for developing interface coatings. The most exciting and new development in the field is the discovery of monazite as a potential interface material for mullite- and alumina-based composites. Monazite offers two critical properties to the CMC system; a weakly bonded layer due to its non-wetting behavior and chemical compatibility with both alumina and mullite up to very high temperatures (> 1,600 C). Other interesting concepts with intensive material development efforts are also being pursued and a brief discussion of these are given in the main text. While demonstration of new interface concepts seems to be the primary objective in most studies, difficulties in processing of interface coatings and designing reliable test methods for determining interface properties have actually retarded the progress. Some of the concepts appear to be simple in nature but require sophisticated processing schemes to develop the coatings. Multilayered coatings with each layer serving specific function are also being proposed. Recent studies also show that significant degradation in fiber strength (30--50%) can result from merely applying the interface coating. These factors have compounds the complexity of interface tailoring in CMCs leading to a need for specific solution for a specific CMC system.

Sambasivan, S.

1998-06-09T23:59:59.000Z

223

Research & Development of Materials/Processing Methods for Continuous Fiber Ceramic Composites (CFCC) Phase 2 Final Report.  

SciTech Connect (OSTI)

The Department of Energy's Continuous Fiber Ceramic Composites (CFCC) Initiative that begun in 1992 has led the way for Industry, Academia, and Government to carry out a 10 year R&D plan to develop CFCCs for these industrial applications. In Phase II of this program, Dow Corning has led a team of OEM's, composite fabricators, and Government Laboratories to develop polymer derived CFCC materials and processes for selected industrial applications. During this phase, Dow Corning carried extensive process development and representative component demonstration activities on gas turbine components, chemical pump components and heat treatment furnace components.

Szweda, A.

2001-01-01T23:59:59.000Z

224

Long-term performance of ceramic matrix composites at elevated temperatures: Modelling of creep and creep rupture  

SciTech Connect (OSTI)

The models developed, contain explicit dependences on constituent material properties and their changes with time, so that composite performance can be predicted. Three critical processes in ceramic composites at elevated temperatures have been modeled: (1) creep deformation of composite vs stress and time-dependent creep of fibers and matrix, and failure of these components; (2) creep deformation of ``interface`` around broken fibers; and (3) lifetime of the composite under conditions of fiber strength loss over time at temperature. In (1), general evolution formulas are derived for relaxation time of matrix stresses and steady-state creep rate of composite; the model is tested against recent data on Ti-MMCs. Calculations on a composite of Hi-Nicalon fibers in a melt-infiltrated SiC matrix are presented. In (2), numerical simulations of composite failure were made to map out time-to-failure vs applied load for several sets of material parameters. In (3), simple approximate relations are obtained between fiber life and composite life that should be useful for fiber developers and testers. Strength degradation data on Hi-Nicalon fibers is used to assess composite lifetime vs fiber lifetime for Hi-Nicalon fiber composites.

Curtin, W.A.; Fabeny, B.; Ibnabdeljalil, M.; Iyengar, N.; Reifsnider, K.L. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Engineering Science and Mechanics

1996-07-31T23:59:59.000Z

225

Toughened Silcomp composites for gas turbine engine applications. Continuous fiber ceramic composites program: Phase I final report, April 1992--June 1994  

SciTech Connect (OSTI)

The two main factors driving the development of new industrial gas turbine engine systems are fuel efficiency and reduced emissions. One method of providing improvements in both areas is to reduce the cooling air requirements of the hot gas path components. For this reason ceramic components are becoming increasingly attractive for gas turbine applications because of their greater refractoriness and oxidation resistance. Among the ceramics being considered, continuous fiber ceramic composites (CFCCs) are leading candidates because they combine the high temperature stability of ceramics with the toughness and damage tolerance of composites. The purpose of this program, which is part of DOE`s CFCC initiative, is to evaluate the use of CFCC materials as gas turbine engine components, and to demonstrate the feasibility of producing such components from Toughened Silcomp composites. Toughened silcomp is a CFCC material made by a reactive melt infiltration process, and consists of continuous SiC reinforcing fibers, with an appropriate fiber coating, in a fully dense matrix of SiC and Si. Based on the material physical properties, the material/process improvements realized in Phase 1, and the preliminary design analyses from Task 1, they feel the feasibility of fabricating Toughened Silcomp with the requisite physical and mechanical properties for the intended applications has been demonstrated. Remaining work for Phase 2 is to further improve the system for enhanced oxidation resistance, incorporate additional process controls to enhance the reproducibility of the material, transition the fabrication process to the selected vendors for scale-up, develop a more complete material property data base, including long-term mechanical behavior, and fabricate and test preliminary ``representative part`` specimens.

Corman, G.S.; Luthra, K.L.; Brun, M.K.; Meschter, P.J.

1994-07-01T23:59:59.000Z

226

High-speed, low-damage grinding of advanced ceramics Phase 1. Final report  

SciTech Connect (OSTI)

In manufacture of structural ceramic components, grinding costs can comprise up to 80% of the entire manufacturing cost. Most of these costs arise from the conventional multi-step grinding process with numerous grinding wheels and additional capital equipment, perishable dressing tools, and labor. In an attempt to reduce structural ceramic grinding costs, a feasibility investigation was undertaken to develop a single step, roughing-finishing process suitable for producing high-quality silicon nitride ceramic parts at high material removal rates at lower cost than traditional, multi-stage grinding. This feasibility study employed combined use of laboratory grinding tests, mathematical grinding models, and characterization of resultant material surface condition. More specifically, this Phase 1 final report provides a technical overview of High-Speed, Low-Damage (HSLD) ceramic grinding and the conditions necessary to achieve the small grain depths of cut necessary for low damage grinding while operating at relatively high material removal rates. Particular issues addressed include determining effects of wheel speed and material removal rate on resulting mode of material removal (ductile or brittle fracture), limiting grinding forces, calculation of approximate grinding zone temperatures developed during HSLD grinding, and developing the experimental systems necessary for determining HSLD grinding energy partition relationships. In addition, practical considerations for production utilization of the HSLD process are also discussed.

Kovach, J.A. [Eaton Corp., Willoughby Hills, OH (United States). Mfg. Technologies Center; Malkin, S. [Univ. of Massachusetts (United States)

1995-03-01T23:59:59.000Z

227

Development of improved processing and evaluation methods for high reliability structural ceramics for advanced heat engine applications, Phase 1. Final report  

SciTech Connect (OSTI)

The program goals were to develop and demonstrate significant improvements in processing methods, process controls and non-destructive evaluation (NDE) which can be commercially implemented to produce high reliability silicon nitride components for advanced heat engine applications at temperatures to 1,370{degrees}C. The program focused on a Si{sub 3}N{sub 4}-4% Y{sub 2}O{sub 3} high temperature ceramic composition and hot-isostatic-pressing as the method of densification. Stage I had as major objectives: (1) comparing injection molding and colloidal consolidation process routes, and selecting one route for subsequent optimization, (2) comparing the performance of water milled and alcohol milled powder and selecting one on the basis of performance data, and (3) adapting several NDE methods to the needs of ceramic processing. The NDE methods considered were microfocus X-ray radiography, computed tomography, ultrasonics, NMR imaging, NMR spectroscopy, fluorescent liquid dye penetrant and X-ray diffraction residual stress analysis. The colloidal consolidation process route was selected and approved as the forming technique for the remainder of the program. The material produced by the final Stage II optimized process has been given the designation NCX 5102 silicon nitride. According to plan, a large number of specimens were produced and tested during Stage III to establish a statistically robust room temperature tensile strength database for this material. Highlights of the Stage III process demonstration and resultant database are included in the main text of the report, along with a synopsis of the NCX-5102 aqueous based colloidal process. The R and D accomplishments for Stage I are discussed in Appendices 1--4, while the tensile strength-fractography database for the Stage III NCX-5102 process demonstration is provided in Appendix 5. 4 refs., 108 figs., 23 tabs.

Pujari, V.K.; Tracey, D.M.; Foley, M.R.; Paille, N.I.; Pelletier, P.J.; Sales, L.C.; Wilkens, C.A.; Yeckley, R.L. [Norton Co., Northboro, MA (United States)

1993-08-01T23:59:59.000Z

228

Push-out tests on a new silicon carbide/reaction-bonded silicon carbide ceramic matrix composite  

SciTech Connect (OSTI)

Fiber push-out tests have been performed on a ceramic matrix composite consisting of Carborundum sintered SiC fibers, with a BN coating, embedded in a reaction-bonded SiC matrix. Analysis of the push-out data, utilizing the most complete theory presently available, shows that one of the fiber/coating/matrix interfaces has a low fracture energy (one-tenth that of the fiber) and a moderate sliding resistance [tau] [approximately] 8 MPa. The debonded sliding interface shows some continuous but minor abrasion, which appears to increase the sliding resistance, but overall the system exhibits very clean smooth sliding. The tensile response of a full-scale composite is then modeled, using data obtained here and known fiber strengths, to demonstrate the good composite behavior predicted for this material.

Curtin, W.A. (BP Research, Cleveland, OH (United States)); Eldridge, J.I. (NASA Lewis Research Center, Cleveland, OH (United States)); Srinivasan, G.V. (Carborundum Co., Niagara Falls, NY (United States))

1993-09-01T23:59:59.000Z

229

Subcritical Crack Growth in Ceramic Composites at High Temperature Measured Using Digital Image Correlation  

SciTech Connect (OSTI)

An in situ experimental technique is described that allows high resolution, high sensitivity determination of displacements and full-field strains during high temperature mechanical testing. The technique is used to investigate elevated temperature crack growth in SiC/Nicalon sub f composites. At 1150 degrees C, the reinforcing fibers have a higher creep susceptibility than the matrix. Fiber creep leads to relaxation of crack bridging tractions, resulting in subcritical crack growth. Differential image analysis is used to measure the crack opening displacement profile u(x) of an advancing, bridged crack. With appropriate modeling, such data can be used to determine the traction law, from which the mechanics of cracking and failure may be determined.

Mumm, D.R.; Morris, W.L.; Dadkhah, M.S.; Cox, B.N.

1996-01-11T23:59:59.000Z

230

MECHANICAL PROPERTIES OF POROUS PNZT POLYCRYSTALLINE CERAMICS  

E-Print Network [OSTI]

in Two-Phase Brittle-Matrix Ceramic Composites," Ibid. , R.ceramic. Spherical pores (110-150ym diameter) were introduced by using The matrix

Biswas, D.R.

2010-01-01T23:59:59.000Z

231

Development of radiation-hardened ceramic composites for fusion applications. Technical progress report, September 1, 1993--August 31, 1994  

SciTech Connect (OSTI)

The strength and toughness of continuous fiber reinforced ceramic composites (CFCC) are highly dependent on the fiber strength distribution. To first order, weaker fibers lead to low strength but higher toughness while stronger fibers lead to high strength composites of relatively low toughness. Toughness is associated with pullout of the fibers from the ceramic matrix. It has been shown previously that both strength and toughness of SiC/Nicalon{sup TM} composites are drastically changed following irradiation. This paper will present and discuss results for low oxygen Nicalon fibers irradiated at three damage levels; 0.013 dpa, 0.13 dpa, and 0.32 dpa. Single fibers were tensile tested and analyzed, using Weibull statistics, for mean strength and distribution. Tensile modulus was also determined. Using a diffractometer, the fiber grain size and percent crystallinity were determined. The initial results of these low level neutron irradiations exhibit no substantial degradation of the properties investigated. Therefore, continued research at higher doses is recommended.

Osborne, M.C.; Steiner, D. [Rensselaer Polytechnic Institute, Troy, NY (United States); Snead, L.L. [Oak Ridge National Lab., TN (United States)

1994-05-01T23:59:59.000Z

232

High speed low damage grinding of advanced ceramics - Phase II Final Report  

SciTech Connect (OSTI)

In the manufacture of structural ceramic components, grinding costs can comprise up to 80% of the entire manufacturing cost. As a result, one of the most challenging tasks faced by manufacturing process engineers is the development of a ceramic finishing process to maximize part throughput while minimizing costs and associated scrap levels. The efforts summarized in this report represent the second phase of a program whose overall objective was to develop a single-step, roughing-finishing process suitable for producing high-quality silicon nitride parts at high material removal rates and at substantially lower cost than traditional, multi-stage grinding processes. More specifically, this report provides a technical overview of High-Speed, Low-Damage (HSLD) ceramic grinding which employs elevated wheel speeds to achieve the small grain depths of cut necessary for low-damage grinding while operating at relatively high material removal rates. The study employed the combined use of laboratory grinding tests, mathematical grinding models, and characterization of the resultant surface condition. A single-step, roughing-finishing process operating at high removal rates was developed and demonstrated.

Kovach, J.A.; Malkin, S.

2000-02-01T23:59:59.000Z

233

Studying the sintering behavior of BeO{sub x}-SiC{sub 1-x} Composite ceramic Material  

SciTech Connect (OSTI)

The sintering behavior for BeO-SiC compacts composite ceramic at different sintering temperatures in air were conducted, resulting data indicated that the percentage of SiC (Wt% 5) sintered at 800 C deg. lead to higher sintering density of (1.80 gm/cm3). The x-ray diffraction pattern analysis indicated nothing change concerning the crystal structure. Microstructure development has been studied as a function SiC content. Silicon carbide found to be suppressed the sinter ability of the matrix BeO powder.

Issa, Tarik Talib [Department of physics, College of Science, University of Baghdad, Jadiriya, Baghdad (Iraq)

2011-12-26T23:59:59.000Z

234

Process of producing a ceramic matrix composite article and article formed thereby  

SciTech Connect (OSTI)

A CMC article and process for producing the article to have a layer on its surface that protects a reinforcement material within the article from damage. The method entails providing a body containing a ceramic reinforcement material in a matrix material that contains a precursor of a ceramic matrix material. A fraction of the reinforcement material is present and possibly exposed at a surface of the body. The body surface is then provided with a surface layer formed of a slurry containing a particulate material but lacking the reinforcement material of the body. The body and surface layer are heated to form the article by converting the precursor within the body to form the ceramic matrix material in which the reinforcement material is contained, and by converting the surface layer to form the protective layer that covers any fraction of the reinforcement material exposed at the body surface.

Corman, Gregory Scot (Ballston Lake, NY); McGuigan, Henry Charles (Duanesburg, NY); Brun, Milivoj Konstantin (Ballston Lake, NY)

2011-10-25T23:59:59.000Z

235

Process of producing a ceramic matrix composite article and article formed thereby  

DOE Patents [OSTI]

A CMC article and process for producing the article to have a layer on its surface that protects a reinforcement material within the article from damage. The method entails providing a body containing a ceramic reinforcement material in a matrix material that contains a precursor of a ceramic matrix material. A fraction of the reinforcement material is present and possibly exposed at a surface of the body. The body surface is then provided with a surface layer formed of a slurry containing a particulate material but lacking the reinforcement material of the body. The body and surface layer are heated to form the article by converting the precursor within the body to form the ceramic matrix material in which the reinforcement material is contained, and by converting the surface layer to form the protective layer that covers any fraction of the reinforcement material exposed at the body surface.

Corman, Gregory Scot; McGuigan, Henry Charles; Brun, Milivoj Konstantin

2010-05-04T23:59:59.000Z

236

Improved process for the preparation of fiber-reinforced ceramic composites by chemical vapor deposition  

DOE Patents [OSTI]

A specially designed apparatus provides a steep thermal gradient across the thickness of fibrous preform. A flow of gaseous ceramic matrix material is directed into the fibrous preform at the cold surface. The deposition of the matrix occurs progressively from the hot surface of the fibrous preform toward the cold surface. Such deposition prevents the surface of the fibrous preform from becoming plugged. As a result thereof, the flow of reactant matrix gases into the uninfiltrated (undeposited) portion of the fibrous preform occurs throughout the deposition process. The progressive and continuous deposition of ceramic matrix within the fibrous preform provides for a significant reduction in process time over known chemical vapor deposition processes.

Lackey, W.J. Jr.; Caputo, A.J.

1984-09-07T23:59:59.000Z

237

ADVANCED ELECTRON BEAM TECHNIQUES FOR METALLIC AND CERAMIC PROTECTIVE COATING SYSTEMS  

E-Print Network [OSTI]

W. Fairbanks, "Advanced Gas Turbine Coatings for MinimallyResistance Coatings for Gas Turbine Airfoils, 11 Finaltion of Super alloys for Gas Turbine Engines, 11 J, Metals,

Boone, Donald H.

2013-01-01T23:59:59.000Z

238

Determination of Interfacial Mechanical Properties of Ceramic Composites by the Compression of Micro-pillar Test Specimens  

SciTech Connect (OSTI)

A novel method to determine the fiber-matrix interfacial properties of ceramic matrix composites is proposed and evaluated; where micro- pillar samples containing inclined fiber/matrix interfaces were prepared from a SiC fiber reinforced SiC matrix composites then compression-tested using the nano-indentation technique. This new test method employs a simple geometry and mitigates the uncertainties associated with complex stress state in the conventional single filament push-out method for the determination of interfacial properties. Based on the test results using samples with different interface orientations , the interfacial debond shear strength and the internal friction coefficient are explicitly determined and compared with values obtained by other test methods.

Shih, Chunghao [ORNL; Katoh, Yutai [ORNL; Leonard, Keith J [ORNL; Bei, Hongbin [ORNL; Lara-Curzio, Edgar [ORNL

2013-01-01T23:59:59.000Z

239

Investigation of forced and isothermal chemical vapor infiltrated SiC/SiC ceramic matrix composites. Final report  

SciTech Connect (OSTI)

Mechanical properties of two different layups for each of the forced CVI (41 specimens) and isothermal CVI (36 specimens) materials were investigated in air at room temperature (RT), 1000C, and at room temperature after thermal shock (RT/TS) and exposure to oxidation (RT/OX). The FCVI specimens had a nominal interfacial coating thickness of 0.3 {mu}m of pyrolytic carbon, while CVI specimens had a coating thickness of 0.1 {mu}m. Effect of reinforcement and interfacial bond on mechanical properties of composite were investigated. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed to analyze the fiber-matrix interface and the toughening mechanisms in this ceramic composite system.

Sankar, J.; Kelkar, A.D.; Vaidyanathan, R. [North Carolina Agricultural and Technical State Univ., Greensboro, NC (United States). Dept. of Mechanical Engineering

1993-09-01T23:59:59.000Z

240

The Production of Advanced Glass Ceramic HLW Forms using Cold Crucible Induction Melter  

SciTech Connect (OSTI)

Cold Crucible Induction Melters (CCIMs) will favorably change how High-Level radioactive Waste (from nuclear fuel recovery) is treated in the 21st century. Unlike the existing Joule-Heated Melters (JHMs) currently in operation for the glass-based immobilization of High-Level Waste (HLW), CCIMs offer unique material features that will increase melt temperatures, increase throughput, increase mixing, increase loading in the waste form, lower melter foot prints, eliminate melter corrosion and lower costs. These features not only enhance the technology for producing HLW forms, but also provide advantageous attributes to the waste form by allowing more durable alternatives to glass. This paper discusses advantageous features of the CCIM, with emphasis on features that overcome the historical issues with the JHMs presently utilized, as well as the benefits of glass ceramic waste forms over borosilicate glass waste forms. These advantages are then validated based on recent INL testing to demonstrate a first-of-a-kind formulation of a non-radioactive ceramic-based waste form utilizing a CCIM.

Veronica J Rutledge; Vince Maio

2013-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "advanced ceramic composites" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Manufacturing and performance of ceramic/metal matrix composite electrical discharge machining electrodes  

E-Print Network [OSTI]

or nickel, (2) the use of a 6% hydrogen in argon environment, and (3) the use of an oxygen getter furnace. Using one or a combination of the above three methods allowed for infiltration of ceramics that were previously impossible to infiltrate. Both a high...

Kim, Eugene Ty

1998-01-01T23:59:59.000Z

242

Robocast Pb(Zr{sub 0.95}Ti{sub 0.05})O{sub 3} Ceramic Monoliths and Composites  

SciTech Connect (OSTI)

Robocasting, a computer controlled slurry deposition technique, was used to fabricate ceramic monoliths and composites of chemically prepared Pb(Zr{sub 0.95}Ti{sub 0.05})O{sub 3} (PZT 95/5) ceramics. Densities and electrical properties of the robocast samples were equivalent to those obtained for cold isostatically pressed (CIP) parts formed at 200 MPa. Robocast composites consisting of alternate layers of the following sintered densities: (93.9%--96.1%--93.9%), were fabricated using different levels of organic pore former additions. Modification from a single to a multiple material deposition robocaster was essential to the fabrication of composites that could withstand repeated cycles of saturated polarization switching under 30 kV/cm fields. Further, these composites withstood 500 MPa hydrostatic pressure induced poled ferroelectric (FE) to antiferroelectric (AFE) phase transformation during which strain differences on the order of 0.8% occurred between composite elements.

TUTTLE,BRUCE A.; SMAY,JAMES E.; CESARANO III,JOSEPH; VOIGT,JAMES A.; SCOFIELD,TIMOTHY W.; OLSON,WALTER R.; LEWIS,J.A.

2000-07-18T23:59:59.000Z

243

Preparation and microwave characterization of BaNd{sub 2-x}Sm{sub x}Ti{sub 4}O{sub 12} (0 {<=} x {<=} 2) ceramics and their effect on the temperature coefficient of dielectric constant in polytetrafluoroethylene composites  

SciTech Connect (OSTI)

High dielectric and temperature-stable ceramic compositions have been prepared through solid-state ceramic route. The structure and microstructure of the ceramics have been studied using powder X-ray diffraction and scanning electron microscopic techniques. The dielectric properties of well-sintered ceramics are studied in the microwave frequency region using Hakki and Coleman post-resonator technique. The samples exhibited high dielectric constant (>77), relatively high quality factor (>1500) and near zero temperature coefficient of resonant frequency. Phase pure calcined ceramic materials are incorporated in the polytetrafluoroethylene matrix through a proprietary process comprising of sigma mixing, extrusion, calendering followed by hot pressing for the fabrication of planar circuit laminates. The effect of temperature coefficient of dielectric constant of the resultant polytetrafluoroethylene/ceramic composite materials is studied with respect to compositional variation of the filler materials.

Stanly Jacob, K.; Satheesh, R. [Centre for Materials for Electronics Technology, Department of Information Technology, Ministry of Communication and Information Technology, Govt. of India, M.G. Kavu, Athani P.O., Thrissur 680771, Kerala (India); Ratheesh, R., E-mail: ratheeshr@yahoo.com [Centre for Materials for Electronics Technology, Department of Information Technology, Ministry of Communication and Information Technology, Govt. of India, M.G. Kavu, Athani P.O., Thrissur 680771, Kerala (India)

2009-10-15T23:59:59.000Z

244

advanced composition explorer: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Syllabus Energy Storage, Conversion and Utilization Websites Summary: for composite materials with special emphasis on polymer matrix composites; analysis of fiber processing...

245

Microwave processing of ceramic oxide filaments. Annual report, FY1997  

SciTech Connect (OSTI)

The objective of the microwave filament processing project is to develop microwave techniques to manufacture continuous ceramic oxide filaments. Microwave processing uses the volumetric absorption of microwave power in oxide filament tows to drive off process solvents, to burn out organic binders, and to sinter the dried fibers to produce flexible, high-strength ceramic filaments. The technical goal is to advance filament processing technology by microwave heating more rapidly with less energy and at a lower cost than conventional processing, but with the same quality as conventional processing. The manufacturing goal is to collaborate with the 3M Company, a US manufacturer of ceramic oxide filaments, to evaluate the technology using a prototype filament system and to transfer the microwave technology to the 3M Company. Continuous ceramic filaments are a principal component in many advanced high temperature materials like continuous fiber ceramic composites (CFCC) and woven ceramic textiles. The use of continuous ceramic filaments in CFCC radiant burners, gas turbines, waste incineration, and hot gas filters in U.S. industry and power generation is estimated to save at least 2.16 quad/yr by year 2010 with energy cost savings of at least $8.1 billion. By year 2010, continuous ceramic filaments and CFCC`s have the potential to abate pollution emissions by 917,000 tons annually of nitrous oxide and 118 million tons annually of carbon dioxide (DOE Report OR-2002, February, 1994).

Vogt, G.J.

1998-12-31T23:59:59.000Z

246

An advanced 3D boundary element method for characterizations of composite materials  

E-Print Network [OSTI]

An advanced 3D boundary element method for characterizations of composite materials X.L. Chena , Y developments in the modeling of composite materials using the boundary element method (BEM) are presented in dealing with nearly-singular integrals, which arise in the BEM modeling of composite materials

Liu, Yijun

247

Modeling of damage in unidirectional ceramic matrix composites and multi-scale experimental validation on third generation SiC/SiC minicomposites  

E-Print Network [OSTI]

1 Modeling of damage in unidirectional ceramic matrix composites and multi-scale experimental to macroscopic tensile tests, the evolution of microscopic damage mechanisms - in the form of matrix cracks and computed tomography tensile tests. A complete model, including both matrix cracking and fiber breaking

Paris-Sud XI, Université de

248

Ceramic/metal and A15/metal superconducting composite materials exploiting the superconducting proximity effect and method of making the same  

DOE Patents [OSTI]

A composite superconducting material made of coated particles of ceramic superconducting material and a metal matrix material. The metal matrix material fills the regions between the coated particles. The coating material is a material that is chemically nonreactive with the ceramic. Preferably, it is silver. The coating serves to chemically insulate the ceramic from the metal matrix material. The metal matrix material is a metal that is susceptible to the superconducting proximity effect. Preferably, it is a NbTi alloy. The metal matrix material is induced to become superconducting by the superconducting proximity effect when the temperature of the material goes below the critical temperature of the ceramic. The material has the improved mechanical properties of the metal matrix material. Preferably, the material consists of approximately 10% NbTi, 90% coated ceramic particles (by volume). Certain aspects of the material and method will depend upon the particular ceramic superconductor employed. An alternative embodiment of the invention utilizes A15 compound superconducting particles in a metal matrix material which is preferably a NbTi alloy.

Holcomb, Matthew J. (Manhattan Beach, CA)

1999-01-01T23:59:59.000Z

249

Interfaces in polymer, ceramic, and metal matrix composites; Proceedings of the Second International Conference on Composite Interfaces (ICCI-II), Cleveland, OH, June 13-17, 1988  

SciTech Connect (OSTI)

The present conference on interfacial factors in advanced composite materials discusses such topics in their development status and properties as silane coupling, the electrochemical and plasma-surface treatment of carbon fibers, fiber surface-analytical techniques, polymer molecular scale characterization by atom-probe field-ion microscopy, the study of carbon fiber-epoxy resin interface interactions by means of labeling techniques, and the surface tailoring of SiC by ion implantation. Also discussed are developments in laser light-scattered photoelasticity, microstructural evolutions under heat treatment and radiation damage, TEM for composites, the interfaces of carbon fiber-reinforced Al composites, the influence of the interface on macroscopic composite properties, and the status of the theoretical understanding of composite interfaces.

Ishida, H.

1988-01-01T23:59:59.000Z

250

The effect of fiber coating thickness on the interfacial properties of a continuous fiber ceramic matrix composite  

SciTech Connect (OSTI)

The interfacial properties (coefficient of friction, residual clamping stress, residual axial stress, and debond stress) of a continuous fiber ceramic composite were determined by means of single-fiber push-out tests. The composite consisted of Nicalon{trademark} fibers, that had been coated prior to matrix infiltration with carbon layers ranging in thickness from 0.03 to 1.2 {mu}m, and a SiC matrix. It was found that the effective interfacial frictional stress decreased as the thickness of the carbon layer increased, from 24.6 {plus_minus} 9.9 MPa for a thickness of 0.03 Jim to 5.8 {plus_minus} 1.4 MPa for a thickness of 1.25 {mu}m. It was also found that both the coefficient of friction and the residual clamping stress decreased as the thickness of the carbon layer increased. These results are explained in terms of the state of residual stresses in this composite and the role of the fiber surface topography during fiber sliding.

Lara-Curzio, E.; Ferber, M.K.; Lowden, R.A.

1994-09-01T23:59:59.000Z

251

Studies of dynamic contact of ceramics and alloys for advanced heat engines. Final report  

SciTech Connect (OSTI)

Advanced materials and coatings for low heat rejection engines have been investigated for almost a decade. Much of the work has concentrated on the critical wear interface between the piston ring and cylinder liner. Simplified bench tests have identified families of coatings with high temperature wear performance that could meet or exceed that of conventional engine materials at today`s operating temperatures. More recently, engine manufacturers have begun to optimize material combinations and manufacturing processes so that the materials not only have promising friction and wear performance but are practical replacements for current materials from a materials and manufacturing cost standpoint. In this study, the advanced materials supplied by major diesel engine manufacturers were evaluated in an experimental apparatus that simulates many of the in-cylinder conditions of a low heat rejection diesel engine. Results include ring wear factors and average dynamic friction coefficients measured at intervals during the test. These results are compared with other advanced materials tested in the past as well as the baseline wear of current engines. Both fabricated specimens and sections of actual ring and cylinder liners were used in the testing. Observations and relative friction and wear performance of the individual materials are provided.

Gaydos, P.A.; Dufrane, K.F. [Battelle, Columbus, OH (United States)

1993-06-01T23:59:59.000Z

252

Effect of sample test volume and geometry on the tensile mechanical behavior of SiC/SiC continuous fiber ceramic composites. Final report  

SciTech Connect (OSTI)

The development of a silicon carbide-type fiber from an organometallic precursor has led to a major resurgence of interest in fiber-reinforced ceramic matrix composites. By combining this high strength fiber with a variety of ceramic matrices it has been possible to achieve tough composites offering significant potential advantages over monolithic ceramics and carbon-carbon for high temperature applications. A continuous-fiber ceramic matrix composite (CFCC) typical of materials proposed for such industrial applications as power generation, heat recovery and chemical production as well as biomedical and environmental applications was tested in uniaxial tension using a universal test machine. Test parameters investigated included: test mode (load versus displacement), test rate (0.003 mm/s, 0.03 mm/s, 50 N/s and 500 N/s), specimen geometry (straight-sided versus reduced-gauge section) and type of specimen volume (long/thin versus short/fat). Typical properties include an average elastic modulus 130 {+-} 10 Gpa, an average proportional limit stress of 45 {+-} 20 Mpa, an average ultimate tensile strength of 180 {+-} 20 MPa and an average modulus of toughness of 8.4 {+-} 2 (x10{sup 5})J/m{sup 3}.

Sankar, J.; Kelkar, A.D.; Neogi, J.

1998-09-01T23:59:59.000Z

253

Novel Ceramic-Polymer Composite Membranes for the Separation of Hazardous Liquid Waste  

SciTech Connect (OSTI)

The present project was conceived to address the need for robust yet selective membranes suitable for operating in harsh ph, solvent, and temperature environments. An important goal of the project was to develop a membrane chemical modification technology that would allow one to tailor-design membranes for targeted separation tasks. The method developed in the present study is based on the process of surface graft polymerization. Using essentially the same base technology of surface modification the research was aimed at demonstrating that improved membranes can be designed for both pervaporation separation and ultrafiltration. In the case of pervaporation, the present study was the first to demonstrate that pervaporation can be achieved with ceramic support membranes modified with an essentially molecular layer of terminally anchored polymer chains. The main advantage of the above approach, relative to other proposed membranes, is that the separating polymer layer is covalently attached to the ceramic support. Therefore, such membranes have a potential use in organic-organic separations where the polymer can swell significantly yet membrane robustness is maintained due to the chemical linkage of the chains to be inorganic support. The above membrane technology was also useful in developing fouling resistant ultrafiltration membranes. The prototype membrane developed in the project was evaluated for the treatment of oil-in-water microemulsions, demonstrating lack of irreversible fouling common with commercial membranes.

Yoram Cohen

2001-12-01T23:59:59.000Z

254

AMO's New Institute for Advanced Composites Manufacturing Innovation...  

Energy Savers [EERE]

as strong and twice as light as the lightest metals. These advanced materials have the potential to transform products ranging from wind turbines to automobiles. This new...

255

advanced thermoplastic composites: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

??Given high strength-to-weight and stiffness-to-weight ratios, sandwich composite materials are continually being considered for automotive applications. Thermoplastic...

256

1Plastic deformation and fracture processes in metallic and ceramic nanomaterials... 2007 Advanced Study Center Co. Ltd.  

E-Print Network [OSTI]

1Plastic deformation and fracture processes in metallic and ceramic nanomaterials... © 2007-mail: ovidko@def.ipme.ru PLASTIC DEFORMATION AND FRACTURE PROCESSES IN METALLIC AND CERAMIC NANOMATERIALS at the boundaries between the large grains and nanoscale matrix. In the framework of the model, cracks are generated

Ovid'ko Ilya A.

257

CVD apparatus and process for the preparation of fiber-reinforced ceramic composites  

DOE Patents [OSTI]

An apparatus and process for the chemical vapor deposition of a matrix into a preform having circumferentially wound ceramic fibers, comprises heating one surface of the preform while cooling the other surface thereof. The resulting product may have fibers that are wound on radial planes or at an angle from the radial planes. The fibers can also be precoated with pyrolytic carbon before application of the matrix. The matrix is applied by passing reactant gas through the preform thereof to the other side thereof for the initial deposition of matrix near such other surface of the preform. The matrix fills in the preform from the other side surface thereof to the surface of the side of application thereof until a desired amount of matrix has been deposited. 6 figs.

Caputo, A.J.; Devore, C.E.; Lowden, R.A.; Moeller, H.H.

1990-01-23T23:59:59.000Z

258

CVD apparatus and process for the preparation of fiber-reinforced ceramic composites  

DOE Patents [OSTI]

An apparatus and process for the chemical vapor deposition of a matrix into a preform having circumferentially wound ceramic fibers, comprises heating one surface of the preform while cooling the other surface thereof. The resulting product may have fibers that are wound on radial planes or at an angle from the radial planes. The fibers can also be precoated with pyrolytic carbon before application of the matrix. The matrix is applied by passing reactant gas through the preform thereof to the other side thereof for the initial deposition of matrix near such other surface of the preform. The matrix fills in the preform from the other side surface thereof to the surface of the side of application thereof until a desired amount of matrix has been deposited.

Caputo, Anthony J. (Knoxville, TN); Devore, Charles E. (Knoxville, TN); Lowden, Richard A. (Powell, TN); Moeller, Helen H. (Concord, VA)

1990-01-01T23:59:59.000Z

259

Method of fabricating metal- and ceramic- matrix composites and functionalized textiles  

SciTech Connect (OSTI)

A method of manufacturing an article comprises providing a first sheet, wetting the first sheet with a liquid precursor to provide a first wet sheet, and irradiating the first wet sheet in a pattern corresponding to a first cross section of the article such that the liquid precursor is at least partially converted to a solid in the first cross section. A second sheet is disposed adjacent to the first sheet. The method further comprises wetting the second sheet with the liquid precursor to provide a second wet sheet, and irradiating the second wet sheet in a pattern corresponding to a second cross section of the article such that the liquid precursor is at least partially converted to a solid in the second cross section. In particular the liquid precursor may be converted to a metal, ceramic, semiconductor, semimetal, or a combination of these materials.

Maxwell, James L. (Jemez Springs, NM); Chavez, Craig A. (Los Alamos, NM); Black, Marcie R. (Lincoln, MA)

2012-04-17T23:59:59.000Z

260

Advanced Fuels for LWRs: Fully-Ceramic Microencapsulated and Related Concepts FY 2012 Interim Report  

SciTech Connect (OSTI)

This report summarizes the progress in the Deep Burn project at Idaho National Laboratory during the first half of fiscal year 2012 (FY2012). The current focus of this work is on Fully-Ceramic Microencapsulated (FCM) fuel containing low-enriched uranium (LEU) uranium nitride (UN) fuel kernels. UO2 fuel kernels have not been ruled out, and will be examined as later work in FY2012. Reactor physics calculations confirmed that the FCM fuel containing 500 mm diameter kernels of UN fuel has positive MTC with a conventional fuel pellet radius of 4.1 mm. The methodology was put into place and validated against MCNP to perform whole-core calculations using DONJON, which can interpolate cross sections from a library generated using DRAGON. Comparisons to MCNP were performed on the whole core to confirm the accuracy of the DRAGON/DONJON schemes. A thermal fluid coupling scheme was also developed and implemented with DONJON. This is currently able to iterate between diffusion calculations and thermal fluid calculations in order to update fuel temperatures and cross sections in whole-core calculations. Now that the DRAGON/DONJON calculation capability is in place and has been validated against MCNP results, and a thermal-hydraulic capability has been implemented in the DONJON methodology, the work will proceed to more realistic reactor calculations. MTC calculations at the lattice level without the correct burnable poison are inadequate to guarantee zero or negative values in a realistic mode of operation. Using the DONJON calculation methodology described in this report, a startup core with enrichment zoning and burnable poisons will be designed. Larger fuel pins will be evaluated for their ability to (1) alleviate the problem of positive MTC and (2) increase reactivity-limited burnup. Once the critical boron concentration of the startup core is determined, MTC will be calculated to verify a non-positive value. If the value is positive, the design will be changed to require less soluble boron by, for example, increasing the reactivity hold-down by burnable poisons. Then, the whole core analysis will be repeated until an acceptable design is found. Calculations of departure from nucleate boiling ratio (DNBR) will be included in the safety evaluation as well. Once a startup core is shown to be viable, subsequent reloads will be simulated by shuffling fuel and introducing fresh fuel. The PASTA code has been updated with material properties of UN fuel from literature and a model for the diffusion and release of volatile fission products from the SiC matrix material . Preliminary simulations have been performed for both normal conditions and elevated temperatures. These results indicated that the fuel performs well and that the SiC matrix has a good retention of the fission products. The path forward for fuel performance work includes improvement of metallic fission product release from the kernel. Results should be considered preliminary and further validation is required.

R. Sonat Sen; Brian Boer; John D. Bess; Michael A. Pope; Abderrafi M. Ougouag

2012-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "advanced ceramic composites" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

One-sided infrared thermal imaging for flaw characterization of ceramic matrix composites  

SciTech Connect (OSTI)

One-sided infrared thermal imaging is being used to characterize voids and delamination in SiC/SiC composites. Flaw depth is estimated by examining the decay of surface temperature after application of a thermal pulse. Digital analysis of the surface temperature/time relationship allows characterization of the sizes and positions of defects. Results show that defects of various sizes and depths can be characterized in SiC/SiC composites with the technique.

Deemer, C.; Sun, J. G.; Ellingson, W. A.

2000-05-16T23:59:59.000Z

262

21F.711 Advanced Spanish Conversation and Composition, Spring 2002  

E-Print Network [OSTI]

Subject designed as a logical complement to Advanced Reading and Writing in Spanish. Unlike 21F.713, which focuses primarily on literary language, subject focuses on expository and journalistic writing that examines the ...

Groeger, Margarita

263

Ceramic Technology Project  

SciTech Connect (OSTI)

The Ceramic Technology Project was developed by the USDOE Office of Transportation Systems (OTS) in Conservation and Renewable Energy. This project, part of the OTS's Materials Development Program, was developed to meet the ceramic technology requirements of the OTS's automotive technology programs. Significant accomplishments in fabricating ceramic components for the USDOE and NASA advanced heat engine programs have provided evidence that the operation of ceramic parts in high-temperature engine environments is feasible. These programs have also demonstrated that additional research is needed in materials and processing development, design methodology, and data base and life prediction before industry will have a sufficient technology base from which to produce reliable cost-effective ceramic engine components commercially. A five-year project plan was developed with extensive input from private industry. In July 1990 the original plan was updated through the estimated completion of development in 1993. The objective is to develop the industrial technology base required for reliable ceramics for application in advanced automotive heat engines. The project approach includes determining the mechanisms controlling reliability, improving processes for fabricating existing ceramics, developing new materials with increased reliability, and testing these materials in simulated engine environments to confirm reliability. Although this is a generic materials project, the focus is on the structural ceramics for advanced gas turbine and diesel engines, ceramic bearings and attachments, and ceramic coatings for thermal barrier and wear applications in these engines. To facilitate the rapid transfer of this technology to US industry, the major portion of the work is being done in the ceramic industry, with technological support from government laboratories, other industrial laboratories, and universities.

Not Available

1992-03-01T23:59:59.000Z

264

Compositions and chemical bonding in ceramics by quantitative electron energy-loss spectrometry  

SciTech Connect (OSTI)

Quantitative electron energy-loss spectrometry was applied to a range of ceramic materials at a spatial resolution of <5 nm. Analysis of Fe L{sub 23} white lines indicated a low-spin state with a charge transfer of {approximately}1.5 electrons/atom onto the Fe atoms implanted into (amorphized) silicon carbide. Gradients of 2 to 5% in the Co:O stoichiometry were measured across 100-nm-thick Co{sub 3}O{sub 4} layers in an oxidized directionally solidified CoO-ZrO{sub 2} eutectic, with the highest O levels near the ZrO{sub 2}. The energy-loss near-edge structures were dramatically different for the two cobalt oxides; those for CO{sub 3}O{sub 4} have been incorrectly ascribed to CoO in the published literature. Kinetically stabilized solid solubility occurred in an AlN-SiC film grown by low-temperature molecular beam epitaxy (MBE) on {alpha}(6H)-SiC, and no detectable interdiffusion occurred in couples of MBE-grown AlN on SiC following annealing at up to 1750C. In diffusion couples of polycrystalline AlN on SiC, interfacial 8H sialon (aluminum oxy-nitride) and pockets of Si{sub 3}N{sub 4}-rich {beta}{prime} sialon in the SiC were detected.

Bentley, J.; Horton, L.L. [Oak Ridge National Lab., TN (United States); McHargue, C.J. [Tennessee Univ., Knoxville, TN (United States); McKernan, S.; Carter, C.B. [Minnesota Univ., Minneapolis, MN (United States). Dept. of Chemical Engineering; Revcolevschi, A. [Univ. de Paris-Sud, Lab. de Chemie des Solides (France); Tanaka, S.; Davis, R.F. [North Carolina State Univ., Raleigh, NC (United States). Dept. of Materials Science and Engineering

1993-12-31T23:59:59.000Z

265

Characterization and control of the fiber-matrix interface in ceramic matrix composites  

SciTech Connect (OSTI)

Fiber-reinforced SiC composites fabricated by thermal-gradient forced-flow chemical-vapor infiltration (FCVI) have exhibited both composite (toughened) and brittle behavior during mechanical property evaluation. Detailed analysis of the fiber-matrix interface revealed that a silica layer on the surface of Nicalon Si-C-O fibers tightly bonds the fiber to the matrix. The strongly bonded fiber and matrix, combined with the reduction in the strength of the fibers that occurs during processing, resulted in the observed brittle behavior. The mechanical behavior of Nicalon/SiC composites has been improved by applying thin coatings (silicon carbide, boron, boron nitride, molybdenum, carbon) to the fibers, prior to densification, to control the interfacial bond. Varying degrees of bonding have been achieved with different coating materials and film thicknesses. Fiber-matrix bond strengths have been quantitatively evaluated using an indentation method and a simple tensile test. The effects of bonding and friction on the mechanical behavior of this composite system have been investigated. 167 refs., 59 figs., 18 tabs.

Lowden, R.A.

1989-03-01T23:59:59.000Z

266

Advanced titania nanostructures and composites for lithium ion battery  

E-Print Network [OSTI]

. Wei Department of Chemistry and Biochemistry, Lamar University, Beaumont, TX 77710, USA Z. Guo (&) Integrated Composites Laboratory (ICL), Dan F. Smith Department of Chemical Engineering, Lamar University, Beaumont, TX 77710, USA e-mail: zhanhu.guo@lamar.edu 123 J Mater Sci (2012) 47:2519­2534 DOI 10.1007/s10853

Guo, John Zhanhu

267

Thermodynamics and kinetics of ceramic/metal interfacial interactions  

E-Print Network [OSTI]

Ceramic/metal interfaces occur in a great number of important applications, such as ceramic/metal composites, microelectronics packaging, ceramic/metal seals, and so forth. Understanding the formation and evolution of such ...

Arróyave, Raymundo, 1975-

2004-01-01T23:59:59.000Z

268

Lightweight high performance ceramic material  

DOE Patents [OSTI]

A sintered ceramic composition includes at least 50 wt. % boron carbide and at least 0.01 wt. % of at least one element selected from the group consisting of Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy Ho, Er, Tm, Yb, and Lu, the sintered ceramic composition being characterized by a density of at least 90% of theoretical density.

Nunn, Stephen D [Knoxville, TN

2008-09-02T23:59:59.000Z

269

Development of Dielectric Material with Ceramic Matrix Composite (CMC) Produced from Kaolinite and CaCu{sub 3}Ti{sub 4}O{sub 12} (CCTO)  

SciTech Connect (OSTI)

Ceramic matrix composites (CMC) combine reinforcing ceramic phases, CaCu{sub 3}Ti{sub 4}O{sub 12} (CCTO) with a ceramic matrix, kaolinite to create materials with new and superior properties. 10% and 20% CCTO were prepared by using a conventional solid state reaction method. CMC samples were pre-sintered at 800 deg. C and sintered at 1000 deg. C. The dielectric properties of samples were measured using HP 4192A LF Impedance Analyzer. Microstructures of the samples were observed using an optical microscope. XRD was used to determine the crystalline structure of the samples. The AFM showed the morphology of the samples. The results showed that the dielectric constant and dielectric loss factor of both samples are frequency dependent. At 10 Hz, the dielectric constant is 10{sup 11} for both samples. The CMC samples were independent with temperature with low dielectric constant in the frequency range of 10{sup 4}-10{sup 6} Hz. Since the CMC samples consist of different amount of kaolinite, so each sample exhibit different defect mechanism. Different reaction may occur for different composition of material. The effects of processing conditions on the microstructure and electrical properties of CMC are also discussed.

Yin, Wong Swee; Hassan, Jumiah; Hashim, Mansor; See, Alex; Yusoff, W. Mohd. Daud W. [Physics Department, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia)

2008-05-20T23:59:59.000Z

270

Novel, Ceramic Membrane System For Hydrogen Separation  

SciTech Connect (OSTI)

Separation of hydrogen from coal gas represents one of the most promising ways to produce alternative sources of fuel. Ceramatec, teamed with CoorsTek and Sandia National Laboratories has developed materials technology for a pressure driven, high temperature proton-electron mixed conducting membrane system to remove hydrogen from the syngas. This system separates high purity hydrogen and isolates high pressure CO{sub 2} as the retentate, which is amenable to low cost capture and transport to storage sites. The team demonstrated a highly efficient, pressure-driven hydrogen separation membrane to generate high purity hydrogen from syngas using a novel ceramic-ceramic composite membrane. Recognizing the benefits and limitations of present membrane systems, the all-ceramic system has been developed to address the key technical challenges related to materials performance under actual operating conditions, while retaining the advantages of thermal and process compatibility offered by the ceramic membranes. The feasibility of the concept has already been demonstrated at Ceramatec. This project developed advanced materials composition for potential integration with water gas shift rectors to maximize the hydrogenproduction.

Elangovan, S.

2012-12-31T23:59:59.000Z

271

Bonding and Structure of Ceramic-Ceramic Interfaces Kohei Shimamura,1,2,3  

E-Print Network [OSTI]

interfacial debonding and sliding in situ during the cracking of ceramic matrix com- posites at highBonding and Structure of Ceramic-Ceramic Interfaces Kohei Shimamura,1,2,3 Fuyuki Shimojo,1,2 Rajiv interfacial design of high-temperature ceramic composites for broad applications such as power generation

Southern California, University of

272

The influence of fiber/matrix interface on the mechanical behavior of Nicalon SiC fiber reinforced glass-ceramic composites  

SciTech Connect (OSTI)

Mechanical properties of unidirectional Nicalon SiC fiber reinforced Ca aluminosilicate (CAS/SiC) and Mg aluminosilicate (MAS/SiC) glass-ceramic composites were investigated by tensile testing and nondestructive laser-ultrasound technique. The Ba-stuffed MAS was either undoped or doped with 5% borosilicate glass. Degradation of elastic stiffness constant C{sub 11} in transverse direction due to interface damage was monitored in situ by measuring the laser- generated ultrasound wave velocity. The three composite materials show different characteristics of macroscopic deformation behavior, which is correlated strongly to interface degradation. A stronger reduction trend of the elastic constant C{sub 11} is associated with a larger degree of inelastic deformation. The fracture surfaces also reveal the close relation between fiber pullout length and interfacial characteristics. Interfaces of these composites were studied by TEM; their influence on inhibiting and deflecting matrix cracks is discussed.

Liu, Y.M.; Mitchell, T.E. [Los Alamos National Lab., NM (United States); Wadley, H.N.G. [Virginia Univ., Charlottesville, VA (United States). Dept. of Materials Science and Engineering

1996-11-01T23:59:59.000Z

273

Notch sensitivity of fatigue life in a Sylramic TM composite at elevated temperature  

E-Print Network [OSTI]

sensitivity; Fatigue; SiC composite; Embrittlement 1. Introduction Continuous-fiber ceramic composites (CFCCs in advanced gas turbine engines. The motivation for this activity is the desire to increase operating are expelled during unloading and the oxidizing atmosphere drawn into the composite through matrix cracks

Zok, Frank

274

High-temperature corrosion in advanced combustion systems  

SciTech Connect (OSTI)

Conceptual designs of advanced combustion systems that utilize coal as a feedstock require high temperature furnaces and heat transfer surfaces capable of operation at much elevated temperatures than those prevalent in current coal-fired power plants. The combination of elevated temperatures and hostile combustion environments necessitate development/application of advanced ceramic materials in these designs. The present paper characterizes the chemistry of coal-fired combustion environments over a wide temperature range of interest in these systems and discusses preliminary experimental results on several materials with potential for application in these systems. An experimental program has been initiated to evaluate materials for advanced combustion systems. Several candidate materials have been identified for evaluation. The candidates included advanced metallic alloys, monolithic ceramics, ceramic particulate/ceramic matrix composites, ceramic fiber/ceramic matrix composites, and ceramic whisker/ceramic matrix composites. The materials examined so far included nickel-base superalloys, alumina, stabilized zirconia, different types of silicon carbide, and silicon nitride. Coupon specimens of several of the materials have been tested in an air environment at 1000, 1200, and 1400{degree}C for 168 h. In addition, specimens were exposed to sodium-sulfate-containing salts at temperatures of 1000 and 1200{degree}C for 168 h. Extensive microstructural analyses were conducted on the exposed specimens to evaluate the corrosion performance of the materials for service in air and fireside environments of advanced coal-fired boilers. Additional tests are underway with several of the materials to evaluate their corrosion performance as a function of salt chemistry, alkali vapor concentration, gas chemistry, exposure temperature, and exposure time.

Natesan, K.; Yanez-Herrero, M.; Fornasieri, C.

1993-11-01T23:59:59.000Z

275

Analysis of nanostructure and nanochemistry by ASAXS: Accessing phase composition of oxyfluoride glass ceramics doped with Er{sup 3+}/Yb{sup 3+}  

SciTech Connect (OSTI)

Here, we describe the analysis of the nanostructure and average chemical compositions of each phase present in an oxyfluoride glass ceramic, which is composed of fluoride nanocrystals and an oxide glass matrix. The overall composition of the oxyfluoride glass ceramic as prepared is 21.1%SiO{sub 2} 6.5%B{sub 2}O{sub 3} 7.0%Al{sub 2}O{sub 3} 21.0%PbF{sub 2} 14.3%CdF{sub 2} 11.0%YbF{sub 3} 0.5%ErF{sub 3} 11.0%PbO 7.6%CdO(mole %). Nanocrystals begin to grow at temperatures above the glass transformation temperature at 678 K as observed by x-ray diffraction. We report results from anomalous small-angle x-ray scattering taken at energies of x-ray absorption edges of Er, Yb, Pb, and Cd. By nonlinear regression of the scattering curves obtained from different edges simultaneously, the nanocrystals were found to be describable as polydisperse spheroids. The length of the smaller axis was found to be 6.4+-1.4 nm while the larger axis was found to be 17.7+-3.9 nm. By analyzing the scattering contrast as a function of the x-ray energy we found cadmium only in the glass matrix.

Haas, Sylvio; Hoell, Armin; Wurth, Roman; Ruessel, Christian; Boesecke, Peter; Vainio, Ulla [Institute of Applied Materials, Helmholtz-Zentrum Berlin fuer Materialien und Energie, Albert-Einstein-Strasse 15, D-12489 Berlin (Germany); Otto-Schott-Institut fuer Glaschemie, Friedrich-Schiller-Universitaet Jena, Fraunhoferstrasse 6, D-07743 Jena (Germany); European Synchrotron Radiation Facility (ESRF), 6 Rue Jules Horowitz, BP 220, 38043 Grenoble Cedex 9 (France); HASYLAB at DESY, Notkestrasse 85, D-22607 Hamburg (Germany)

2010-05-01T23:59:59.000Z

276

Stress-Rupture, Overstressing and a Proposed New Methodology to Assess the Durability and Reliability of Ceramic Matrix Composites at Elevated Temperatures  

SciTech Connect (OSTI)

A new testing strategy is proposed to assess the durability and reliability of non- oxide continuous fiber-reinforced ceramic composites for high temperature structural applications. The strategy is based on determining the reliability (probability of failure) of these materials when subjected to random loading schedules consisting of load and temperature spikes that are superimposed on otherwise constant stress and temperature histories. The frequency and magnitude of the load and temperature spikes would be representative of the number and characteristics of the transients that are associated with a particular industrial application and that are expected to occur over the life of the component. The effect of overstressing on the stress- ruptttre behavior of a CG-NicalonTM fiber-reinforced SiC composite was investigated and results arc presented from tests conducted in ambient air at 950"C.

Lara-Curzio, E.

1999-07-05T23:59:59.000Z

277

Dense high temperature ceramic oxide superconductors  

DOE Patents [OSTI]

Dense superconducting ceramic oxide articles of manufacture and methods for producing these articles are described. Generally these articles are produced by first processing these superconducting oxides by ceramic processing techniques to optimize materials properties, followed by reestablishing the superconducting state in a desired portion of the ceramic oxide composite.

Landingham, Richard L. (Livermore, CA)

1993-01-01T23:59:59.000Z

278

Dense high temperature ceramic oxide superconductors  

DOE Patents [OSTI]

Dense superconducting ceramic oxide articles of manufacture and methods for producing these articles are described. Generally these articles are produced by first processing these superconducting oxides by ceramic processing techniques to optimize materials properties, followed by reestablishing the superconducting state in a desired portion of the ceramic oxide composite.

Landingham, R.L.

1993-10-12T23:59:59.000Z

279

Development of low-expansion ceramics with strength retention to elevated temperatures. Final report  

SciTech Connect (OSTI)

The development of advanced engines has resulted in the need for new ceramic compositions which exhibit thermo-mechanical properties suitable for the engine environment, e.g., low thermal expansion, stability to 1,200 C, and thermal shock resistance. To meet these goals, a two phase research program was instituted. In the first phase, new oxide ceramics were identified in the AlPO{sub 4}-{beta}-eucryptite, {beta}-cristobalite, mullite and zircon systems. This research focused on screening and property characterization of ceramics in the four systems. The most promising compositions in the AlPO{sub 4}-{beta}-eucryptite and zircon systems were then further evaluated and developed in the second phase with the goal of being ready for prototype testing in actual engines. Of the compositions, calcium magnesium zirconium phosphate (zircon system) exhibits the most desirable properties and is presently being developed for commercialization.

Hirschfeld, D.A.; Brown, J.J. Jr. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States)

1994-09-01T23:59:59.000Z

280

Corrosion resistant ceramic materials  

DOE Patents [OSTI]

Ceramic materials are disclosed which exhibit stability in severely-corrosive environments having high alkali-metal activity, high sulfur/sulfide activity and/or molten halides at temperatures of 200--550 C or organic salt (including SO{sub 2} and SO{sub 2}Cl{sub 2}) at temperatures of 25--200 C. These sulfide ceramics form stoichiometric (single-phase) compounds with sulfides of Ca, Li, Na, K, Al, Mg, Si, Y, La, Ce, Ga, Ba, Zr and Sr and show melting-points that are sufficiently low and have excellent wettability with many metals (Fe, Ni, Mo) to easily form metal/ceramic seals. Ceramic compositions are also formulated to adequately match thermal expansion coefficient of adjacent metal components. 1 fig.

Kaun, T.D.

1996-07-23T23:59:59.000Z

Note: This page contains sample records for the topic "advanced ceramic composites" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Corrosion resistant ceramic materials  

DOE Patents [OSTI]

Ceramic materials which exhibit stability in severely-corrosive environments having high alkali-metal activity, high sulfur/sulfide activity and/or molten halides at temperatures of 200.degree.-550.degree. C. or organic salt (including SO.sub.2 and SO.sub.2 Cl.sub.2) at temperatures of 25.degree.-200.degree. C. These sulfide ceramics form stoichiometric (single-phase) compounds with sulfides of Ca, Li, Na, K, Al, Mg, Si, Y, La, Ce, Ga, Ba, Zr and Sr and show melting-points that are sufficiently low and have excellent wettability with many metals (Fe, Ni, Mo) to easily form metal/ceramic seals. Ceramic compositions are also formulated to adequately match thermal expansion coefficient of adjacent metal components.

Kaun, Thomas D. (320 Willow St., New Lenox, IL 60451)

1995-01-01T23:59:59.000Z

282

Corrosion resistant ceramic materials  

DOE Patents [OSTI]

Ceramic materials which exhibit stability in severely-corrosive environments having high alkali-metal activity, high sulfur/sulfide activity and/or molten halides at temperatures of 200.degree.-550.degree. C. or organic salt (including SO.sub.2 and SO.sub.2 Cl.sub.2) at temperatures of 25.degree.-200.degree. C. These sulfide ceramics form stoichiometric (single-phase) compounds with sulfides of Ca, Li, Na, K, Al, Mg, Si, Y, La, Ce, Ga, Ba, Zr and Sr and show melting-points that are sufficiently low and have excellent wettability with many metals (Fe, Ni, Mo) to easily form metal/ceramic seals. Ceramic compositions are also formulated to adequately match thermal expansion coefficient of adjacent metal components.

Kaun, Thomas D. (320 Willow St., New Lenox, IL 60451)

1996-01-01T23:59:59.000Z

283

International Conference on Advanced Composite Materials in Bridges and Structures Confrence Internationale sur les matriaux composites d'avant-garde pour ponts et charpentes  

E-Print Network [OSTI]

6th International Conference on Advanced Composite Materials in Bridges and Structures 6ième a very low thermally conductive material. Carbon fiber (CFRP) was chosen for this research, instead Conférence Internationale sur les matériaux composites d'avant-garde pour ponts et charpentes Kingston

284

On the fracture toughness of advanced materials  

E-Print Network [OSTI]

particularly in ceramic-matrix composites; by utilizingmatrix/fiber interfaces, are added for strength and stiffness; to a lesser degree, continuous glass and ceramic

Launey, Maximilien E.

2009-01-01T23:59:59.000Z

285

Ductile Ni.sub.3 Al alloys as bonding agents for ceramic materials  

DOE Patents [OSTI]

An improved ceramic-metal composite comprising a mixture of a ceramic material with a ductile intermetallic alloy, preferably Ni.sub.3 Al.

Tiegs, Terry N. (Lenoir City, TN); McDonald, Robert R. (Traverse City, MI)

1990-01-01T23:59:59.000Z

286

Process for strengthening silicon based ceramics  

SciTech Connect (OSTI)

A process for strengthening silicon based ceramic monolithic materials and composite materials that contain silicon based ceramic reinforcing phases that requires that the ceramic be exposed to a wet hydrogen atmosphere at about 1400{degrees}C. The process results in a dense, tightly adherent silicon containing oxide layer that heals, blunts, or otherwise negates the detrimental effect of strength limiting flaws on the surface of the ceramic body.

Kim, Hyoun-Ee; Moorhead, A.J.

1991-03-07T23:59:59.000Z

287

Bio-inspired tailored hydroxyapatite-based powder composites for dental applications  

E-Print Network [OSTI]

can reinforce the ceramic matrix composites; however, thean HAP matrix because it exhibits both ceramic and metallic

Lin, Yen-Shan

2012-01-01T23:59:59.000Z

288

Polymer Coating for Immobilizing Soluble Ions in a Phosphate Ceramic Product  

SciTech Connect (OSTI)

A polymer coating is applied to the surface of a phosphate ceramic composite to effectively immobilize soluble salt anions encapsulated within the phosphate ceramic composite. The polymer coating is made from ceramic materials, including at least one inorganic metal compound, that wet and adhere to the surface structure of the phosphate ceramic composite, thereby isolating the soluble salt anions from the environment and ensuring long-term integrity of the phosphate ceramic composite.

Singh, Dileep; Wagh, Arun S.; Patel, Kartikey D.

1999-05-05T23:59:59.000Z

289

SiC/SiC Composite for an Advanced Fusion Power Plant Blanket A. R. Raffray1  

E-Print Network [OSTI]

SiC/SiC Composite for an Advanced Fusion Power Plant Blanket A. R. Raffray1 , L. El-Guebaly2 , D. K, and constraints relating to the SiC/SiC properties are discussed. INTRODUCTION The use of SiC/SiC composite

290

Enabling Technologies for Ceramic Hot Section Components  

SciTech Connect (OSTI)

Silicon-based ceramics are attractive materials for use in gas turbine engine hot sections due to their high temperature mechanical and physical properties as well as lower density than metals. The advantages of utilizing ceramic hot section components include weight reduction, and improved efficiency as well as enhanced power output and lower emissions as a result of reducing or eliminating cooling. Potential gas turbine ceramic components for industrial, commercial and/or military high temperature turbine applications include combustor liners, vanes, rotors, and shrouds. These components require materials that can withstand high temperatures and pressures for long duration under steam-rich environments. For Navy applications, ceramic hot section components have the potential to increase the operation range. The amount of weight reduced by utilizing a lighter gas turbine can be used to increase fuel storage capacity while a more efficient gas turbine consumes less fuel. Both improvements enable a longer operation range for Navy ships and aircraft. Ceramic hot section components will also be beneficial to the Navy's Growth Joint Strike Fighter (JSF) and VAATE (Versatile Affordable Advanced Turbine Engines) initiatives in terms of reduced weight, cooling air savings, and capability/cost index (CCI). For DOE applications, ceramic hot section components provide an avenue to achieve low emissions while improving efficiency. Combustors made of ceramic material can withstand higher wall temperatures and require less cooling air. Ability of the ceramics to withstand high temperatures enables novel combustor designs that have reduced NO{sub x}, smoke and CO levels. In the turbine section, ceramic vanes and blades do not require sophisticated cooling schemes currently used for metal components. The saved cooling air could be used to further improve efficiency and power output. The objectives of this contract were to develop technologies critical for ceramic hot section components for gas turbine engines. Significant technical progress has been made towards maturation of the EBC and CMC technologies for incorporation into gas turbine engine hot-section. Promising EBC candidates for longer life and/or higher temperature applications relative to current state of the art BSAS-based EBCs have been identified. These next generation coating systems have been scaled-up from coupons to components and are currently being field tested in Solar Centaur 50S engine. CMC combustor liners were designed, fabricated and tested in a FT8 sector rig to demonstrate the benefits of a high temperature material system. Pretest predictions made through the use of perfectly stirred reactor models showed a 2-3x benefit in CO emissions for CMC versus metallic liners. The sector-rig test validated the pretest predictions with >2x benefit in CO at the same NOx levels at various load conditions. The CMC liners also survived several trip shut downs thereby validating the CMC design methodology. Significant technical progress has been made towards incorporation of ceramic matrix composites (CMC) and environmental barrier coatings (EBC) technologies into gas turbine engine hot-section. The second phase of the program focused on the demonstration of a reverse flow annular CMC combustor. This has included overcoming the challenges of design and fabrication of CMCs into 'complex' shapes; developing processing to apply EBCs to 'engine hardware'; testing of an advanced combustor enabled by CMCs in a PW206 rig; and the validation of performance benefits against a metal baseline. The rig test validated many of the pretest predictions with a 40-50% reduction in pattern factor compared to the baseline and reductions in NOx levels at maximum power conditions. The next steps are to develop an understanding of the life limiting mechanisms in EBC and CMC materials, developing a design system for EBC coated CMCs and durability testing in an engine environment.

Venkat Vedula; Tania Bhatia

2009-04-30T23:59:59.000Z

291

Application of advanced composites for efficient on-board storage of fuel in natural gas vehicles  

SciTech Connect (OSTI)

The following outlines the performance requirements for high pressure containers for on-board storage of fuel in Natural Gas Vehicles. The construction of state-of-the-art carbon-fiber reinforced all-composite cylinders is described and the validation testing and key advantages are discussed. Carbon-fiber reinforced advanced composite technology offers a number of key advantages to the NGV industry, by providing: improved range, including up to 30% more fuel storage for a given storage envelope and up to 300% more fuel storage for a given weight allowance; life-cycle cost advantages, including savings in non-recurring costs (installation), savings in recurring costs (fuel and maintenance), and increased revenues from more passengers/payload; and uncompromising safety, namely, superior resistance to degradation from fatigue or stress rupture and inherent resistance to corrosion; proven toughness/impact resistance.

Sirosh, S.N. [EDO Canada Ltd., Calgary, Alberta (Canada)

1995-11-01T23:59:59.000Z

292

Solid composite electrolytes for lithium batteries  

DOE Patents [OSTI]

Solid composite electrolytes are provided for use in lithium batteries which exhibit moderate to high ionic conductivity at ambient temperatures and low activation energies. In one embodiment, a ceramic-ceramic composite electrolyte is provided containing lithium nitride and lithium phosphate. The ceramic-ceramic composite is also preferably annealed and exhibits an activation energy of about 0.1 eV.

Kumar, Binod (Dayton, OH); Scanlon, Jr., Lawrence G. (Fairborn, OH)

2000-01-01T23:59:59.000Z

293

Dielectric, ferromagnetic and maganetoelectric properties of BaTiO{sub 3}–Ni{sub 0.7}Zn{sub 0.3}Fe{sub 2}O{sub 4} composite ceramics  

SciTech Connect (OSTI)

Graphical abstract: - Highlights: • The lead-free ME ceramic composites BaTiO{sub 3}–Ni{sub 0.7}Zn{sub 0.3}Fe{sub 2}O{sub 4} were successfully synthesized. • The composites showed high dielectric constant and low dielectric loss. • The composite with 30% NiZn ferrite presented good soft magnetic properties and ME performance. - Abstract: Lead-free magnetoelectric composite ceramics (1 ? x)BaTiO{sub 3}–xNi{sub 0.7}Zn{sub 0.3}Fe{sub 2}O{sub 4} (x = 0.15, 0.3, 0.45) were successfully prepared by conventional oxide ceramic process. The tetragonal perovskite BaTiO{sub 3} and cubic spinel Ni{sub 0.7}Zn{sub 0.3}Fe{sub 2}O{sub 4} were confirmed by X-ray diffraction. The dielectric behaviors of all composite samples show a normal response to the increasing measurement frequency and Ni{sub 0.7}Zn{sub 0.3}Fe{sub 2}O{sub 4} ferrite content. Well defined ferromagnetic hysteresis loops and obvious magnetoelectric coupling effect are observed in the composite ceramics. The influence of applied dc bias magnetic field and Ni{sub 0.7}Zn{sub 0.3}Fe{sub 2}O{sub 4} ferrite content on the magnetoelectric coupling responding voltage is investigated. The strongest peak magnetoelectric coupling voltage coefficient is 124 ?V/cm Oe when x = 0.3, which corresponds to the maximum magnetoelectric coupling responding voltage of 200 ?V.

Zhang, Rong-Fen [Department of Electronic Science, College of Science, Key Laboratory of Functional Composite Materials of Guizhou Province, Guizhou University, Guiyang, Guizhou 550025 (China); Deng, Chao-Yong, E-mail: cydeng@gzu.edu.cn [Department of Electronic Science, College of Science, Key Laboratory of Functional Composite Materials of Guizhou Province, Guizhou University, Guiyang, Guizhou 550025 (China); Ren, Li [Department of Electronic Science, College of Science, Key Laboratory of Functional Composite Materials of Guizhou Province, Guizhou University, Guiyang, Guizhou 550025 (China); Li, Zheng [Department of Materials Science and Engineering, State Key Laboratory of New Ceramics and Fine Processing, Tsinghua University, Beijing 100084 (China); Zhou, Jian-Ping [College of Physics and Information Technology, Shaanxi Normal University, Xi’an 710062 (China)

2013-10-15T23:59:59.000Z

294

Cermet composite thermal spray coatings for erosion and corrosion protection in combustion environments of advanced coal-fired boilers. Semi-annual technical progress report, February 1996--July 1996  

SciTech Connect (OSTI)

Present coal-fired boiler environments remain hostile to the materials of choice since corrosion and erosion can be a serious problem in certain regions of the boiler. Recently, the Clean Air Act Amendment is requiring electric power plants to reduce NO{sub x}, emissions to the environment. To reduce NO{sub x}, emissions, new low NO{sub x}, combustors are utilized which burn fuel with a substoichiometric amount of oxygen (i.e., low oxygen partial pressure). In these low NO{sub x} environments, H{sub 2}S gas is a major source of sulfur. Due to the sulfidation process, corrosion rates in reducing parts of boilers have increased significantly and existing boiler tube materials do not always provide adequate corrosion resistance. Combined attack due to corrosion and erosion is a concern because of the significantly increased operating costs which result in material failures. One method to combat corrosion and erosion in coal-fired boilers is to apply coatings to the components subjected to aggressive environments. Thermal spray coatings, a cermet composite comprised of hard ceramic phases of oxide and/or carbide in a metal binder, have been used with some success as a solution to the corrosion and erosion problems in boilers. However, little is known on the effect of the volume fraction, size, and shape of the hard ceramic phase on the erosion and corrosion resistance of the thermally sprayed coatings. It is the objective of this research to investigate metal matrix composite (cermet) coatings in order to determine the optimum ceramic/metal combination that will give the best erosion and corrosion resistance in new advanced coal-fired boilers.

Banovic, S.W.; Levin, B.F.; DuPont, J.N.; Marder, A.R.

1996-08-01T23:59:59.000Z

295

Ceramics International 17 (1991)267-274 Molecular and Colloidal Engineering of  

E-Print Network [OSTI]

and ceramic matrix composites are those produced in nature by a variety of very elegant low examples of molecularly engineered ceramics and ceramic-polymer composite architec- tures.6Ceramics International 17 (1991)267-274 Molecular and Colloidal Engineering of Ceramicst Ilhan A

Aksay, Ilhan A.

296

ADVANCED COMPOSITE WIND TURBINE BLADE DESIGN BASED ON DURABILITY AND DAMAGE TOLERANCE  

SciTech Connect (OSTI)

The objective of the program was to demonstrate and verify Certification-by-Analysis (CBA) capability for wind turbine blades made from advanced lightweight composite materials. The approach integrated durability and damage tolerance analysis with robust design and virtual testing capabilities to deliver superior, durable, low weight, low cost, long life, and reliable wind blade design. The GENOA durability and life prediction software suite was be used as the primary simulation tool. First, a micromechanics-based computational approach was used to assess the durability of composite laminates with ply drop features commonly used in wind turbine applications. Ply drops occur in composite joints and closures of wind turbine blades to reduce skin thicknesses along the blade span. They increase localized stress concentration, which may cause premature delamination failure in composite and reduced fatigue service life. Durability and damage tolerance (D&DT) were evaluated utilizing a multi-scale micro-macro progressive failure analysis (PFA) technique. PFA is finite element based and is capable of detecting all stages of material damage including initiation and propagation of delamination. It assesses multiple failure criteria and includes the effects of manufacturing anomalies (i.e., void, fiber waviness). Two different approaches have been used within PFA. The first approach is Virtual Crack Closure Technique (VCCT) PFA while the second one is strength-based. Constituent stiffness and strength properties for glass and carbon based material systems were reverse engineered for use in D&DT evaluation of coupons with ply drops under static loading. Lamina and laminate properties calculated using manufacturing and composite architecture details matched closely published test data. Similarly, resin properties were determined for fatigue life calculation. The simulation not only reproduced static strength and fatigue life as observed in the test, it also showed composite damage and fracture modes that resemble those reported in the tests. The results show that computational simulation can be relied on to enhance the design of tapered composite structures such as the ones used in turbine wind blades. A computational simulation for durability, damage tolerance (D&DT) and reliability of composite wind turbine blade structures in presence of uncertainties in material properties was performed. A composite turbine blade was first assessed with finite element based multi-scale progressive failure analysis to determine failure modes and locations as well as the fracture load. D&DT analyses were then validated with static test performed at Sandia National Laboratories. The work was followed by detailed weight analysis to identify contribution of various materials to the overall weight of the blade. The methodology ensured that certain types of failure modes, such as delamination progression, are contained to reduce risk to the structure. Probabilistic analysis indicated that composite shear strength has a great influence on the blade ultimate load under static loading. Weight was reduced by 12% with robust design without loss in reliability or D&DT. Structural benefits obtained with the use of enhanced matrix properties through nanoparticles infusion were also assessed. Thin unidirectional fiberglass layers enriched with silica nanoparticles were applied to the outer surfaces of a wind blade to improve its overall structural performance and durability. The wind blade was a 9-meter prototype structure manufactured and tested subject to three saddle static loading at Sandia National Laboratory (SNL). The blade manufacturing did not include the use of any nano-material. With silica nanoparticles in glass composite applied to the exterior surfaces of the blade, the durability and damage tolerance (D&DT) results from multi-scale PFA showed an increase in ultimate load of the blade by 9.2% as compared to baseline structural performance (without nano). The use of nanoparticles lead to a delay in the onset of delamination. Load-displacement relati

Galib Abumeri; Frank Abdi (PhD)

2012-02-16T23:59:59.000Z

297

Heat distribution ceramic processing method  

DOE Patents [OSTI]

A multi-layered heat distributor system is provided for use in a microwave process. The multi-layered heat distributors includes a first inner layer of a high thermal conductivity heat distributor material, a middle insulating layer and an optional third insulating outer layer. The multi-layered heat distributor system is placed around the ceramic composition or article to be processed and located in a microwave heating system. Sufficient microwave energy is applied to provide a high density, unflawed ceramic product.

Tiegs, Terry N. (Lenoir City, TN); Kiggans, Jr., James O. (Oak Ridge, TN)

2001-01-01T23:59:59.000Z

298

Nondestructive characterization of structural ceramic components  

SciTech Connect (OSTI)

Advanced structural ceramic components under development for heat-engine applications include both monolithic and continuous fiber composites (CFC). Nondestructive characterization (NDC) methods being developed differ for each material system. For monolithic materials, characterization during processing steps is important. For many CFC, only post process characterization is possible. Many different NDC systems have been designed and built A 3D x-ray micro computed tomographic (3DXCT) imaging system has been shown to be able to map density variations to better than 3% in pressure slip cast Si{sub 3}N{sub 4} monolithic materials. In addition, 3DXCT coupled to image processing has been shown to be able to map through-thickness fiber orientations in 2D lay-ups of 0{degrees}/45{degrees}, 0{degrees}/75{degrees}, 0{degrees}/90{degrees}, in SiC/SiC CVI CFC. Fourier optics based laser scatter systems have been shown to be able to detect surface and subsurface defects (as well as microstructural variations) in monolithic Si{sub 3}N{sub 4} bearing balls. Infrared methods using photothermal excitation have been shown to be able to detect and measure thermal diffusivity differences on SiC/SiC 2D laminated CFC which have been subjected to different thermal treatments including thermal shock and oxidizing environments. These NDC methods and their applications help provide information to allow reliable usage of ceramics in advanced heat engine applications.

Ellingson, W.A.; Steckenrider, J.S.; Sivers, E.A. [Argonne National Lab., IL (United States); Ling, J.R. [Chinese Academy of Sciences, Shanghai, SH (China). Shanghai Inst. of Ceramics

1994-06-01T23:59:59.000Z

299

Fouling of ceramic filters and thin-film composite reverse osmosis membranes by inorganic and bacteriological constituents  

SciTech Connect (OSTI)

Two significant problems have been identified during the first three years of operating the Savannah River Site Effluent Treatment Facility. These problems encompass two of the facility`s major processing areas: the microfiltration and reverse osmosis steps. The microfilters (crossflow ceramic filters {minus}0.2{mu} nominal pore size) have been prone to pluggage problems. The presence of bacteria and bacteria byproducts in the microfilter feed, along with small quantities of colloidal iron, silica, and aluminum, results in a filter foulant that rapidly deteriorates filter performance and is difficult to remove by chemical cleaning. Processing rates through the filters have dropped from the design flow rate of 300 gpm after cleaning to 60 gpm within minutes. The combination of bacteria (from internal sources) and low concentrations of inorganic species resulted in substantial reductions in the reverse osmosis system performance. The salt rejection has been found to decrease from 99+% to 97%, along with a 50% loss in throughput, within a few hours of cleaning. Experimental work has led to implementation of several changes to plant operation and to planned upgrades of existing equipment. It has been shown that biological control in the influent is necessary to achieve design flowrates. Experiments have also shown that the filter performance can be optimized by the use of efficient filter backpulsing and the addition of aluminum nitrate (15 to 30 mg/L Al{sup 3+}) to the filter feed. The aluminum nitrate assists by controlling adsorption of colloidal inorganic precipitates and biological contaminants. In addition, improved cleaning procedures have been identified for the reverse osmosis units. This paper provides a summary of the plant problems and the experimental work that has been completed to understand and correct these problems.

Siler, J.L.; Poirier, M.R.; McCabe, D.J.; Hazen, T.C.

1991-12-31T23:59:59.000Z

300

Fouling of ceramic filters and thin-film composite reverse osmosis membranes by inorganic and bacteriological constituents  

SciTech Connect (OSTI)

Two significant problems have been identified during the first three years of operating the Savannah River Site Effluent Treatment Facility. These problems encompass two of the facility's major processing areas: the microfiltration and reverse osmosis steps. The microfilters (crossflow ceramic filters {minus}0.2{mu} nominal pore size) have been prone to pluggage problems. The presence of bacteria and bacteria byproducts in the microfilter feed, along with small quantities of colloidal iron, silica, and aluminum, results in a filter foulant that rapidly deteriorates filter performance and is difficult to remove by chemical cleaning. Processing rates through the filters have dropped from the design flow rate of 300 gpm after cleaning to 60 gpm within minutes. The combination of bacteria (from internal sources) and low concentrations of inorganic species resulted in substantial reductions in the reverse osmosis system performance. The salt rejection has been found to decrease from 99+% to 97%, along with a 50% loss in throughput, within a few hours of cleaning. Experimental work has led to implementation of several changes to plant operation and to planned upgrades of existing equipment. It has been shown that biological control in the influent is necessary to achieve design flowrates. Experiments have also shown that the filter performance can be optimized by the use of efficient filter backpulsing and the addition of aluminum nitrate (15 to 30 mg/L Al{sup 3+}) to the filter feed. The aluminum nitrate assists by controlling adsorption of colloidal inorganic precipitates and biological contaminants. In addition, improved cleaning procedures have been identified for the reverse osmosis units. This paper provides a summary of the plant problems and the experimental work that has been completed to understand and correct these problems.

Siler, J.L.; Poirier, M.R.; McCabe, D.J.; Hazen, T.C.

1991-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "advanced ceramic composites" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Continuous Fiber Wound Ceramic Composite (CFCC) for Commercial Water Reactor Fuel. Technical progress report for period ending April 1, 2000  

SciTech Connect (OSTI)

Our program began on August 1, 1999. As of April 1, 2000, the progress has been in materials selection and test planning. Three subcontracts are in place (McDermott Technologies Inc. for continuous fiber reinforced ceramic tubing fabrication, Swales Aerospace for LOCA testing of tubes, and Massachusetts Institute of Technology for In Reactor testing of tubes). With regard to materials selection we visited McDermott Technologies Inc. a number of times, including on February 23, 2000 to discuss the Draft Material Selection and Fabrication Report. The changes discussed at this meeting were implemented and the final version of this report is attached (attachment 1). McDermott Technologies Inc. will produce one type of tubing: Alumina oxide (Nextel 610) fiber, a carbon coating (left in place), and alumina-yttria matrix. A potentially desirable CFCC material of silicon carbide fiber with spinel matrix was discussed. That material selection was not adopted primarily due to material availability and cost. Gamma Engineering is exploring the available tube coatings at Northwestern University as a mechanism for reducing the permeability of the tubes, and thus, will use coating as a differentiating factor in the testing of tubing in the LOCA test as well as the In-Reactor Test. The conclusion of the Material Selection and Fabrication Report lists the possible coatings under evaluation. With regard to Test Planning, the MIT and Swales Aerospace have submitted draft Test Plans. MIT is attempting to accommodate an increased number of test specimens by evaluating alternative test configurations. Swales Aerospace held a design review at their facilities on February 24, 2000 and various engineering alternatives and safety issues were addressed. The final Test Plans are not expected until just before testing begins to allow for incorporation of changes during ''dry runs.''

NONE

2000-04-01T23:59:59.000Z

302

Effect of fiber fabric orientation on the monotonic and fatigue behavior of a continuous fiber ceramic composite  

SciTech Connect (OSTI)

The monotonic fast fracture and fatigue behavior of a Nextel{trademark} 312 reinforced SiC matrix composite was investigated. Effect of fabric orientation with respect to the loading axis on the monotonic and fatigue behavior of the composite was examined. Two geometries were investigated: transverse, where fiber fabric is perpendicular to loading direction; and edge-on where the fabric is parallel to the loading axis. The edge-on geometry showed higher flexure strengths than the transverse orientation. The different deformation mechanisms between the edge-on and transverse orientations were due to strong in-plane shearing of the fiber fabric and weak interlaminar shear of the plies, respectively. In cyclic fatigue, stress versus cycles (S-N) curves showed high fatigue endurance limits in both orientations, although the transverse orientation survived more cycles than the edge-on orientation at stresses slightly above the endurance limit.

Chawla, N.; Liaw, P.K. [Tennessee Univ., Knoxville, TN (United States). Dept. of Materials Science and Engineering; Lara-Curzio, E.; Lowden, R.A.; Ferber, M.K. [Oak Ridge National Lab., TN (United States)

1994-09-01T23:59:59.000Z

303

Electromagnetic properties of microwave sintered ferromagnetic-ferroelectric composites for application in low temperature co-fired ceramic devices  

SciTech Connect (OSTI)

In this paper, microwave sintering (MS) technology has been applied in the preparation of ferromagnetic-ferroelectric composites. Several kinds of (Ni{sub 0.3}Zn{sub 0.6}Cu{sub 0.1})Fe{sub 2}O{sub 4} (NiCuZn) ferrite with different contents of BaTiO{sub 3}(BT) have been fabricated by MS technology. We found that the sintering time and temperature were significantly reduced from 22 h and 1100 deg. C for the conventional sintering (CS) process to 2 h and 840 deg. C for MS process, respectively. Experiments show that MS treated NiCuZn-BT composites possess both excellent ferromagnetic and ferroelectric properties. For the composites of NiCuZn added with 15% BaTiO{sub 3}, the real part of permittivity is larger than 50 below 20 MHz and the real part of dielectric constant is larger than 18 below 1 GHz. Our results indicate that the microwave sintering method is a potential important technique in LTCC technology.

Yang Qinghui; Zhang Huaiwu; Wen Qiye; Liu Yingli [State Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of China, Chendu 610054, Sichuan (China)

2011-04-01T23:59:59.000Z

304

Porous ceramics and method for making  

SciTech Connect (OSTI)

The fabrication of a porous ceramic composite is described. Fumed silica particles are coated with a nitrate, preferably aluminum nitrate. Next the nitrate is converted to an oxide and formed into a desired configuration. This configuration is heated to convert the oxide to an oxide silicate which is then react with HF, resulting in the fluoride ceramic, preferably aluminum fluoride.

Reiner, R.H.; Holcombe, C.E.

1989-06-08T23:59:59.000Z

305

Method of making porous ceramic fluoride  

SciTech Connect (OSTI)

A process is disclosed for making a porous ceramic composite where fumed silica particles are coated with a nitrate, preferably aluminum nitrate. Next the nitrate is converted to an oxide and formed into a desired configuration. This configuration is heated to convert the oxide to an oxide silicate which is then react with HF, resulting in the fluoride ceramic, preferably aluminum fluoride.

Reiner, R.H.; Holcombe, C.E.

1990-11-13T23:59:59.000Z

306

Method of making porous ceramic fluoride  

DOE Patents [OSTI]

A process for making a porous ceramic composite where fumed silica particles are coated with a nitrate, preferably aluminum nitrate. Next the nitrate is converted to an oxide and formed into a desired configuration. This configuration is heated to convert the oxide to an oxide silicate which is then react with HF, resulting in the fluoride ceramic, preferably aluminum fluoride.

Reiner, Robert H. (Knoxville, TN); Holcombe, Cressie E. (Farragut, TN)

1990-01-01T23:59:59.000Z

307

Ceramic component development analysis -- Volume 1. Final report  

SciTech Connect (OSTI)

The development of advanced filtration media for advanced fossil-fueled power generating systems is a critical step in meeting the performance and emissions requirements for these systems. While porous metal and ceramic candle-filters have been available for some time, the next generation of filters will include ceramic-matrix composites (CMCs) (Techniweave/Westinghouse, Babcock and Wilcox (B and W), DuPont Lanxide Composites), intermetallic alloys (Pall Corporation), and alternate filter geometries (CeraMem Separations). The goal of this effort was to perform a cursory review of the manufacturing processes used by 5 companies developing advanced filters from the perspective of process repeatability and the ability for their processes to be scale-up to produce volumes. Given the brief nature of the on-site reviews, only an overview of the processes and systems could be obtained. Each of the 5 companies had developed some level of manufacturing and quality assurance documentation, with most of the companies leveraging the procedures from other products they manufacture. It was found that all of the filter manufacturers had a solid understanding of the product development path. Given that these filters are largely developmental, significant additional work is necessary to understand the process-performance relationships and projecting manufacturing costs.

Boss, D.E.

1998-06-09T23:59:59.000Z

308

Development of improved processing and evaluation methods for high reliability structural ceramics for advanced heat engine applications Phase II. Final report  

SciTech Connect (OSTI)

The research program had as goals the development and demonstration of significant improvements in processing methods, process controls, and nondestructive evaluation (NDE) which can be commercially implemented to produce high reliability silicon nitride components for advanced heat engine applications at temperatures to 1370{degrees}C. In Phase I of the program a process was developed that resulted in a silicon nitride - 4 w% yttria HIP`ed material (NCX 5102) that displayed unprecedented strength and reliability. An average tensile strength of 1 GPa and a strength distribution following a 3-parameter Weibull distribution were demonstrated by testing several hundred buttonhead tensile specimens. The Phase II program focused on the development of methodology for colloidal consolidation producing green microstructure which minimizes downstream process problems such as drying, shrinkage, cracking, and part distortion during densification. Furthermore, the program focused on the extension of the process to gas pressure sinterable (GPS) compositions. Excellent results were obtained for the HIP composition processed for minimal density gradients, both with respect to room-temperature strength and high-temperature creep resistance. Complex component fabricability of this material was demonstrated by producing engine-vane prototypes. Strength data for the GPS material (NCX-5400) suggest that it ranks very high relative to other silicon nitride materials in terms of tensile/flexure strength ratio, a measure of volume quality. This high quality was derived from the closed-loop colloidal process employed in the program.

Pujari, V.J.; Tracey, D.M.; Foley, M.R. [and others

1996-02-01T23:59:59.000Z

309

aluminum matrix composite: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Topic Index 1 Joining of 6061 Aluminum Matrix-Ceramic Particle Reinforced Composites Materials Science Websites Summary: ) ) Joining of 6061 Aluminum Matrix-Ceramic Particle...

310

E-Print Network 3.0 - advanced composites conference Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

3rd ... Source: Mottram, Toby - School of Engineering, University of Warwick Collection: Engineering 15 Composite Web Services Kung-Kiu Lau and Cuong Tran Summary: Composite Web...

311

Comparison of high temperature mechanical properties of two monolithic SiC ceramics and an Al{sub 2}O{sub 3}/SiC composite  

SciTech Connect (OSTI)

Fast fracture strength, slow crack growth, and creep properties have been evaluated for three ceramics in air at room temperature and two elevated temperatures. The ceramics are candidate materials for heat exchangers in fossil energy systems, therefore, retained strength after coal ash exposure was also measured. At 1100{degrees}C the ceramics had acceptable mechanical properties, but two of them exhibited strength loss due to coal ash corrosion. At 1400{degrees}C creep and slow crack growth were observed in two of the materials, and the material which exhibited best resistance to coal ash showed unacceptably high creep rates.

Breder, K.

1995-07-01T23:59:59.000Z

312

Assessment of Silicon Carbide Composites for Advanced Salt-Cooled Reactors  

SciTech Connect (OSTI)

The Advanced High-Temperature Reactor (AHTR) is a new reactor concept that uses a liquid fluoride salt coolant and a solid high-temperature fuel. Several alternative fuel types are being considered for this reactor. One set of fuel options is the use of pin-type fuel assemblies with silicon carbide (SiC) cladding. This report provides (1) an initial viability assessment of using SiC as fuel cladding and other in-core components of the AHTR, (2) the current status of SiC technology, and (3) recommendations on the path forward. Based on the analysis of requirements, continuous SiC fiber-reinforced, chemically vapor-infiltrated SiC matrix (CVI SiC/SiC) composites are recommended as the primary option for further study on AHTR fuel cladding among various industrially available forms of SiC. Critical feasibility issues for the SiC-based AHTR fuel cladding are identified to be (1) corrosion of SiC in the candidate liquid salts, (2) high dose neutron radiation effects, (3) static fatigue failure of SiC/SiC, (4) long-term radiation effects including irradiation creep and radiation-enhanced static fatigue, and (5) fabrication technology of hermetic wall and sealing end caps. Considering the results of the issues analysis and the prospects of ongoing SiC research and development in other nuclear programs, recommendations on the path forward is provided in the order or priority as: (1) thermodynamic analysis and experimental examination of SiC corrosion in the candidate liquid salts, (2) assessment of long-term mechanical integrity issues using prototypical component sections, and (3) assessment of high dose radiation effects relevant to the anticipated operating condition.

Katoh, Yutai [ORNL; Wilson, Dane F [ORNL; Forsberg, Charles W [ORNL

2007-09-01T23:59:59.000Z

313

advanced carbon-carbon composites: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 CARBON-CARBON COMPOSITE ALLCOMP Carbon-Carbon Composite Biology and Medicine Websites Summary: CARBON-CARBON...

314

Ceramic Technology Project semiannual progress report, April 1992--September 1992  

SciTech Connect (OSTI)

This project was developed to meet the ceramic technology requirements of the DOE Office of Transportation Systems` automotive technology programs. Significant progress in fabricating ceramic components for DOE, NASA, and DOE advanced heat engine programs show that operation of ceramic parts in high-temperature engines is feasible; however, addition research is needed in materials and processing, design, and data base and life prediction before industry will have a sufficient technology base for producing reliable cost-effective ceramic engine components commercially. A 5-yr project plan was developed, with focus on structural ceramics for advanced gas turbine and diesel engines, ceramic bearings and attachments, and ceramic coatings for thermal barrier and wear applications in these engines.

Johnson, D.R.

1993-07-01T23:59:59.000Z

315

Nanoscale Reinforced, Polymer Derived Ceramic Matrix Coatings  

SciTech Connect (OSTI)

The goal of this project was to explore and develop a novel class of nanoscale reinforced ceramic coatings for high temperature (600-1000 C) corrosion protection of metallic components in a coal-fired environment. It was focused on developing coatings that are easy to process and low cost. The approach was to use high-yield preceramic polymers loaded with nano-size fillers. The complex interplay of the particles in the polymer, their role in controlling shrinkage and phase evolution during thermal treatment, resulting densification and microstructural evolution, mechanical properties and effectiveness as corrosion protection coatings were investigated. Fe-and Ni-based alloys currently used in coal-fired environments do not possess the requisite corrosion and oxidation resistance for next generation of advanced power systems. One example of this is the power plants that use ultra supercritical steam as the working fluid. The increase in thermal efficiency of the plant and decrease in pollutant emissions are only possible by changing the properties of steam from supercritical to ultra supercritical. However, the conditions, 650 C and 34.5 MPa, are too severe and result in higher rate of corrosion due to higher metal temperatures. Coating the metallic components with ceramics that are resistant to corrosion, oxidation and erosion, is an economical and immediate solution to this problem. Good high temperature corrosion protection ceramic coatings for metallic structures must have a set of properties that are difficult to achieve using established processing techniques. The required properties include ease of coating complex shapes, low processing temperatures, thermal expansion match with metallic structures and good mechanical and chemical properties. Nanoscale reinforced composite coatings in which the matrix is derived from preceramic polymers have the potential to meet these requirements. The research was focused on developing suitable material systems and processing techniques for these coatings. In addition, we investigated the effect of microstructure on the mechanical properties and oxidation protection ability of the coatings. Coatings were developed to provide oxidation protection to both ferritic and austentic alloys and Ni-based alloys. The coatings that we developed are based on low viscosity pre-ceramic polymers. Thus they can be easily applied to any shape by using a variety of techniques including dip-coating, spray-coating and painting. The polymers are loaded with a variety of nanoparticles. The nanoparticles have two primary roles: control of the final composition and phases (and hence the properties); and control of the shrinkage during thermal decomposition of the polymer. Thus the selection of the nanoparticles was the most critical aspect of this project. Based on the results of the processing studies, the performance of selected coatings in oxidizing conditions (both static and cyclic) was investigated.

Rajendra Bordia

2009-07-31T23:59:59.000Z

316

Cermet composite thermal spray coatings for erosion and corrosion protection in combustion environments of advanced coal-fired boilers. Semiannual technical report, January 14, 1997--August 14, 1997  

SciTech Connect (OSTI)

Research is presently being conducted to determine the optimum ceramic/metal combination in thermally sprayed metal matrix composite coatings for erosion and corrosion resistance in new coal-fired boilers. The research will be accomplished by producing model cermet composites using powder metallurgy and electrodeposition methods in which the effect of ceramic/metal combination for the erosion and corrosion resistance will be determined. These results will provide the basis for determining the optimum hard phase constituent size and volume percent in thermal spray coatings. Thermal spray coatings will be applied by our industrial sponsor and tested in our erosion and corrosion laboratories. Bulk powder processed Ni-Al{sub 2}O{sub 3} composites were produced at Idaho National Engineering Laboratory. The composite samples contained 0, 21, 27, 37, and 45 volume percent Al{sub 2}O{sub 3} with an average particle size of 12 um. Also, to deposit model Ni-Al{sub 2}O{sub 3} coatings, an electrodeposition technique was developed and coatings with various volume fractions (0-35%) of Al{sub 2}O{sub 3} were produced. The powder and electrodeposition processing of Ni-Al{sub 2}O{sub 3} Composites provide the ability to produce two phase microstructure without changing the microstructure of the matrix material. Therefore, the effect of hard second phase particles size and volume fraction on erosion resistance could be analyzed.

Schorr, B.S.; Levin, B.F.; DuPont, J.N.; Marder, A.R.

1997-08-31T23:59:59.000Z

317

Ceramic to metal attachment system. [Ceramic electrode to metal conductor in MHD generator  

DOE Patents [OSTI]

A composition and method are described for attaching a ceramic electrode to a metal conductor. A layer of randomly interlocked metal fibers saturated with polyimide resin is sandwiched between the ceramic electrode and the metal conductor. The polyimide resin is then polymerized providing bonding.

Marchant, D.D.

1983-06-10T23:59:59.000Z

318

SURFACES AND INTERFACES IN CERAMIC AND CERAMIC-METAL SYSTEMS  

E-Print Network [OSTI]

Electrical Characterization of Ceramic Oxides: Bulk vs.ELECTRICAL CHARACTERIZATION OF CERAMIC OXIDES: BULK vs.

,

2013-01-01T23:59:59.000Z

319

Ceramics containing dispersants for improved fracture toughness  

DOE Patents [OSTI]

The invention is a ceramic composition containing a new class of dispersant for hindering crack propagation by means of one or more energy-dissipative mechanisms. The composition is composed of a ceramic matrix with dispersed particles of a transformation-prone rare-earth niobate, tantalate or mixtures of these with each other and/or with a rare-earth vanadate. The dispersants, having a generic composition tRMO.sub.4, where R is a rare-earth element, B is Nb or Ta and O is oxygen, are mixed in powder form with a powder of the matrix ceramic and sintered to produce a ceramic form or body. The crack-hindering mechanisms operates to provide improved performance over a wide range of temperature and operating conditions.

Nevitt, Michael V. (Wheaton, IL); Aldred, Anthony T. (Wheaton, IL); Chan, Sai-Kit (Darien, IL)

1987-01-01T23:59:59.000Z

320

Surface Analysis Techniques on Ceramic Materials | GE Global...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

2-3-12-v-robotic-crawler-inspection Robotic Crawler Inspects Wind Turbines a7-v-ceramic-matrix-composites Composites Automation Cuts Production Time Down to Hours ...

Note: This page contains sample records for the topic "advanced ceramic composites" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

In situ toughened SiC ceramics with Al-B-C additions and oxide-coated SiC platelet/SiC composites  

SciTech Connect (OSTI)

This work aimed at fabrication and characterization of high toughness SiC ceramics through the applications of in situ toughening and SiC platelet reinforcement. The processing-microstructure-property relations of hot pressed SiC with Al, B, and C additions (designated as ABC-SiC) were investigated. Through a liquid phase sintering mechanism, dense SiC was obtained by hot pressing at a temperature as low as 1,700 C with 3 wt% Al, 0.6 wt% B, and 2 wt% C additions. These sintering aids also enhanced the {beta}-to-{alpha} (3C-to-4H) phase transformation, which promoted SiC grains to grow into plate-like shapes. Under optimal processing conditions, the microstructure exhibited high-aspect-ratio plate-shaped grains with a thin (< 1 nm) Al-containing amorphous grain boundary film. The mechanical properties of the toughened SiC and the composites were evaluated in comparison with a commercial Hexoloy SiC under identical test conditions. The C-curve behavior was examined using the strength-indentation load relationship and compared with that directly measured using precracked compact tension specimens. The in situ toughened ABC-SiC exhibited much improved flaw tolerance and a significantly rising R-curve behavior. A steady-state toughness in excess of 9 MPam{sup 1/2} was recorded for the ABC-SiC in comparison to a single valued toughness below 3 MPam{sup 1/2} for the Hexoloy. Toughening in the ABC-SiC was mainly attributed to grain bridging and subsequent pullout of the plate-shaped grains. The high toughness ABC-SiC exhibited a bend strength of 650 MPa with a Weibull modulus of 19; in comparison, the commercial SiC showed a bend strength of 400 MPa with a Weibull modulus of 6. Higher fracture toughness was also achieved by the reinforcement of SiC platelets, encapsulated with alumina, yttria, or silica, in a SiC matrix.

Cao, J. [Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering; [Lawrence Berkeley National Lab., CA (United States). Materials Sciences Div.

1996-12-01T23:59:59.000Z

322

Method for joining ceramic shapes  

DOE Patents [OSTI]

A method for joining shapes of ceramic materials together to form a unitary ceramic structure. In the method of the invention, a mixture of two or more chemical components which will react exothermically is placed between the surfaces to be joined, and the joined shapes heated to a temperature sufficient to initiate the exothermic reaction forming a joining material which acts to bond the shapes together. Reaction materials are chosen which will react exothermically at temperatures below the degradation temperature of the materials to be joined. The process is particularly suited for joining composite materials of the silicon carbide-silicon carbide fiber type.

Rabin, Barry H. (Idaho Falls, ID)

1992-01-01T23:59:59.000Z

323

E-Print Network 3.0 - advanced composite laminates Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

stability and environmental resistance... , the measured mode I in- terlaminar fracture toughness should be higher. The composite laminate has poor... laminate or BMI matrix...

324

E-Print Network 3.0 - advanced composite substrate Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Technische Universiteit Delft Collection: Engineering 25 International Composites Expo ICE-98 Nashville, TN, January 19-21, 1998. Title: Strength, Durability and Health...

325

Advanced ultrasonic NDE of composite airframe components: physics, modelling and technology.  

E-Print Network [OSTI]

??In recent years the use of composites in engineering has greatly increased due to the advantages which may be obtained. These are weight savings, increased… (more)

Mienczakowski, Martin

2010-01-01T23:59:59.000Z

326

E-Print Network 3.0 - advanced nano-composite cation-exchanger...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of deformation and damage evolution from DD simulations; Application of the CREEP code to ODS and nano-composited Source: Ghoniem, Nasr M. - Department of Materials...

327

Advances  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAbout the BuildingInnovation PortalScienceScripting forAdvances in

328

REQUEST BY CATERPILLAR INC. FOR AN ADVANCE WAIVER OF DOMESTIC...  

Broader source: Energy.gov (indexed) [DOE]

Caterpillar's demonstrated technical competence in thermal spray applications, wear resistant materials, thin film coatings, ceramics, metal matrix composites, high temperature...

329

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect (OSTI)

In the present quarter, experiments are presented on ceramic/metal interactions of Zirconia/Ni-B-Si system and with a thin Ti coating deposited on zirconia surface. Processing of perovskites of LSC, LSF and LSCF composition for evaluation of mechanical properties as a function of environment are begun. The studies are to be in parallel with LSFCO composition to characterize the segregation of cations and slow crack growth in environmental conditions. La{sub 1-x}Sr{sub x}FeO{sub 3-d} has also been characterized for paramagnetic ordering at room temperature and the evolution of magnetic moments as a function of temperature are investigated. Investigation on the thermodynamic properties of the membrane materials are continued to develop a complete model for the membrane transport.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2003-01-01T23:59:59.000Z

330

Updated FY12 Ceramic Fuels Irradiation Test Plan  

SciTech Connect (OSTI)

The Fuel Cycle Research and Development program is currently devoting resources to study of numerous fuel types with the aim of furthering understanding applicable to a range of reactors and fuel cycles. In FY11, effort within the ceramic fuels campaign focused on planning and preparation for a series of rabbit irradiations to be conducted at the High Flux Isotope Reactor located at Oak Ridge National Laboratory. The emphasis of these planned tests was to study the evolution of thermal conductivity in uranium dioxide and derivative compositions as a function of damage induced by neutron damage. Current fiscal realities have resulted in a scenario where completion of the planned rabbit irradiations is unlikely. Possibilities for execution of irradiation testing within the ceramic fuels campaign in the next several years will thus likely be restricted to avenues where strong synergies exist both within and outside the Fuel Cycle Research and Development program. Opportunities to augment the interests and needs of modeling, advanced characterization, and other campaigns present the most likely avenues for further work. These possibilities will be pursued with the hope of securing future funding. Utilization of synthetic microstructures prepared to better understand the most relevant actors encountered during irradiation of ceramic fuels thus represents the ceramic fuel campaign's most efficient means to enhance understanding of fuel response to burnup. This approach offers many of the favorable attributes embraced by the Separate Effects Testing paradigm, namely production of samples suitable to study specific, isolated phenomena. The recent success of xenon-imbedded thick films is representative of this approach. In the coming years, this strategy will be expanded to address a wider range of problems in conjunction with use of national user facilities novel characterization techniques to best utilize programmatic resources to support a science-based research program.

Nelson, Andrew T. [Los Alamos National Laboratory

2012-05-24T23:59:59.000Z

331

ON THE USE OF DIGITAL IMAGE CORRELATION TO ANALYZE THE MECHANICAL PROPERTIES OF BRITTLE MATRIX COMPOSITES  

E-Print Network [OSTI]

for a ceramic-based braze that can be used to joint ceramics of ceramic-matrix composites. Different strategiesON THE USE OF DIGITAL IMAGE CORRELATION TO ANALYZE THE MECHANICAL PROPERTIES OF BRITTLE MATRIX

Paris-Sud XI, Université de

332

Endommagement et microstructure de composites cramique-cramique sollicits thermiquement  

E-Print Network [OSTI]

la fibre. Abstract. 2014 The behaviour of ceramic-ceramic composites submitted to thermal for ceramic composite operations. Then two SiC fiber reinforced composites have been studied : one with a 2D fiber arrangement and a SiC matrix, the other with a 3D fiber arrangement and a SiO2 matrix

Paris-Sud XI, Université de

333

I Am Crrarn Soc, 1 5 [2] 316-2r (1992) Distribution of Matrix Cracks in a Uniaxial Ceramic Composite  

E-Print Network [OSTI]

Composite Chongdu Cho,*John W. Holmes," and James R. Barber Department of Mechanical Engineering and Applied cracking and debonding in uniaxial composites loaded in tension predict that the matrix stress varies only model of a composite and by direct experimental measurements of crack spacing. In the limit

Barber, James R.

334

Evaluation of bisphenol E cyanate ester for the resin-injection repair of advanced composites  

SciTech Connect (OSTI)

This thesis is a compilation of a general introduction and literature review that ties together the subsequent chapters which consist of two journal articles that have yet to be submitted for publication. The overall topic relates to the evaluation and application of a new class of cyanate ester resin with unique properties that lend it applicable to use as a resin for injection repair of high glass transition temperature polymer matrix composites. The first article (Chapter 2) details the evaluation and optimization of adhesive properties of this cyanate ester and alumina nanocomposites under different conditions. The second article (Chapter 3) describes the development and evaluation of an injection repair system for repairing delaminations in polymer matrix composites.

Wilber Yaote Lio

2009-12-19T23:59:59.000Z

335

Corrosion protection of SiC-based ceramics with CVDMullite coatings  

SciTech Connect (OSTI)

Silicon carbide ceramics are the leading candidate materials for use as heat exchangers in advanced combined cycle power plants because of their unique combination of high temperature strength, high thermal conductivity, excellent thermal shock resistance, and good high temperature stability and oxidation resistance. Ceramic coatings are being considered for diesel engine cylinder liners, piston caps, valve faces and seats, piston rings, and for turbine components such as combustors, blades, stators, seals, and bearings. Under such conditions ceramics are better suited to high temperature environments than metals. For the first time, adherent crystalline mullite coatings have been chemically vapor deposited onto SiC substrates to enhance its corrosion/oxidation resistance. Thermodynamic and kinetic considerations have been utilized to produce mullite coatings with a variety of growth rates, compositions, and morphologies. The flexibility of processing can be exploited to produce coated ceramics with properties tailored to specific applications and varied corrosive environments. These corrosive environments include thermal, Na{sub 2}SO{sub 4}, O{sub 2} and coal slag.

Sarin, V.; Auger, M. [Boston Univ., MA (United States)

1997-05-01T23:59:59.000Z

336

Performance of ceramic membrane filters  

SciTech Connect (OSTI)

CeraMem Corp.`s ceramic-membrane coated, dead-end ceramic filters offer a promising alternative to ceramic candle filters providing long-term operational and reliability issues are resolved: regenerability of filter passages by back pulse cleaning, tolerance to alkali-containing combustion gas and thermal/chemical aging. ANL is responsible for analytical modeling of filtration and pulse cleaning operations, flow-through testing, and prediction of filter response to thermal cycling under realistic service conditions. A test apparatus was built to expose ceramic filter specimens to chemical environments simulating operation of pressurized fluidized bed and integrated gasification combined cycle plants. Four long-duration tests have been conducted in which 100-cpsi channel filters were exposed to ash collected downstream of the cyclone separator at the PFBC plant at Tidd. Results are discussed. Focus has now shifted to exposing the advanced candle filter specimens to reducing gas environments containing NaCl, H{sub 2}S, H{sub 2}O, and gasification ash.

Ahluwalia, R.K.; Im, K.H.; Geyer, H.K. [Argonne National Lab., IL (United States); Shelleman, D.L.; Tressler, R.E. [Pennsylvania State Univ., University Park, PA (United States)

1996-08-01T23:59:59.000Z

337

Novel Processing of Unique Ceramic-Based Nuclear Materials and Fuels  

SciTech Connect (OSTI)

Advances in nuclear reactor technology and the use of gas-cooled fast reactors require the development of new materials that can operate at the higher temperatures expected in these systems. These include refractory alloys base on Nb, Zr, Ta, Mo, W, and Re; ceramics and composites such as those based on silicon carbide (SiCf-SiC); carbon-carbon composites; and advanced coatings. Besides the ability to handle higher expected temperatures, effective heat transfer between reactor componets is necessary for improved efficiency. Improving thermal conductivity of the materials used in nuclear fuels and other temperature critical components can lower the center-line fuel temperature and thereby enhance durability and reduce the risk of premature failure.

Hui Zhang; Raman P. Singh

2008-11-30T23:59:59.000Z

338

Nuclear Energy Research Initiative (NERI) Program Continuous Fiber Wound Ceramic Composite (CFCC) for Commercial Water Reactor Fuel-Technical Progress Report  

SciTech Connect (OSTI)

This project began on August 1, 1999. As of July 1, 2000, the progress has been in materials production, test planning, testing facility design & instruction, and calibration. One new subcontractor was added to provide a solution to the CFCC material permeability issue (Northwestern University). This is in addition to the three subcontracts that were previously in place (McDermott Technologies Inc. for continuous fiber reinforced ceramic tubing fabrication, Swales Aerospace for LOCA testing of tubes, and Massachusetts Institute of Technology for In Reactor testing of tubes).

NONE

2000-07-11T23:59:59.000Z

339

Fracture Toughness Prediction for MWCNT Reinforced Ceramics  

SciTech Connect (OSTI)

This report describes the development of a micromechanics model to predict fracture toughness of multiwall carbon nanotube (MWCNT) reinforced ceramic composites to guide future experimental work for this project. The modeling work described in this report includes (i) prediction of elastic properties, (ii) development of a mechanistic damage model accounting for matrix cracking to predict the composite nonlinear stress/strain response to tensile loading to failure, and (iii) application of this damage model in a modified boundary layer (MBL) analysis using ABAQUS to predict fracture toughness and crack resistance behavior (R-curves) for ceramic materials containing MWCNTs at various volume fractions.

Henager, Charles H.; Nguyen, Ba Nghiep

2013-09-01T23:59:59.000Z

340

Delamination of Ceramic Coatings with Embedded Metal Layers Matthew R. Begleyw  

E-Print Network [OSTI]

sili- con-based ceramic matrix composites from oxidation and evap- orative hydrolysis at elevatedDelamination of Ceramic Coatings with Embedded Metal Layers Matthew R. Begleyw Mechanical ce- ramic coating. I. Introduction LOW-thermal-conductivity ceramic layers are now widely used

Wadley, Haydn

Note: This page contains sample records for the topic "advanced ceramic composites" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Ceramics Technology Project database: September 1991 summary report. [Materials for piston ring-cylinder liner for advanced heat/diesel engines  

SciTech Connect (OSTI)

The piston ring-cylinder liner area of the internal combustion engine must withstand very-high-temperature gradients, highly-corrosive environments, and constant friction. Improving the efficiency in the engine requires ring and cylinder liner materials that can survive this abusive environment and lubricants that resist decomposition at elevated temperatures. Wear and friction tests have been done on many material combinations in environments similar to actual use to find the right materials for the situation. This report covers tribology information produced from 1986 through July 1991 by Battelle columbus Laboratories, Caterpillar Inc., and Cummins Engine Company, Inc. for the Ceramic Technology Project (CTP). All data in this report were taken from the project's semiannual and bimonthly progress reports and cover base materials, coatings, and lubricants. The data, including test rig descriptions and material characterizations, are stored in the CTP database and are available to all project participants on request. Objective of this report is to make available the test results from these studies, but not to draw conclusions from these data.

Keyes, B.L.P.

1992-06-01T23:59:59.000Z

342

CERAMIC WASTE FORM DATA PACKAGE  

SciTech Connect (OSTI)

The purpose of this data package is to provide information about simulated crystalline waste forms that can be used to select an appropriate composition for a Cold Crucible Induction Melter (CCIM) proof of principle demonstration. Melt processing, viscosity, electrical conductivity, and thermal analysis information was collected to assess the ability of two potential candidate ceramic compositions to be processed in the Idaho National Laboratory (INL) CCIM and to guide processing parameters for the CCIM operation. Given uncertainties in the CCIM capabilities to reach certain temperatures throughout the system, one waste form designated 'Fe-MP' was designed towards enabling processing and another, designated 'CAF-5%TM-MP' was designed towards optimized microstructure. Melt processing studies confirmed both compositions could be poured from a crucible at 1600{degrees}C although the CAF-5%TM-MP composition froze before pouring was complete due to rapid crystallization (upon cooling). X-ray diffraction measurements confirmed the crystalline nature and phase assemblages of the compositions. The kinetics of melting and crystallization appeared to vary significantly between the compositions. Impedance spectroscopy results indicated the electrical conductivity is acceptable with respect to processing in the CCIM. The success of processing either ceramic composition will depend on the thermal profiles throughout the CCIM. In particular, the working temperature of the pour spout relative to the bulk melter which can approach 1700{degrees}C. The Fe-MP composition is recommended to demonstrate proof of principle for crystalline simulated waste forms considering the current configuration of INL's CCIM. If proposed modifications to the CCIM can maintain a nominal temperature of 1600{degrees}C throughout the melter, drain, and pour spout, then the CAF-5%TM-MP composition should be considered for a proof of principle demonstration.

Amoroso, J.; Marra, J.

2014-06-13T23:59:59.000Z

343

Ceramic Technology Project semiannual progress report, October 1992--March 1993  

SciTech Connect (OSTI)

This project was developed to meet the ceramic technology requirements of the OTS`s automotive technology programs. Although progress has been made in developing reliable structural ceramics, further work is needed to reduce cost. The work described in this report is organized according to the following work breakdown structure project elements: Materials and processing (monolithics [Si nitride, carbide], ceramic composites, thermal and wear coatings, joining, cost effective ceramic machining), materials design methodology (contact interfaces, new concepts), data base and life prediction (structural qualification, time-dependent behavior, environmental effects, fracture mechanics, nondestructive evaluation development), and technology transfer.

Johnson, D.R.

1993-09-01T23:59:59.000Z

344

Ceramic Technology Project. Semiannual progress report, April 1991--September 1991  

SciTech Connect (OSTI)

The Ceramic Technology Project was developed by the USDOE Office of Transportation Systems (OTS) in Conservation and Renewable Energy. This project, part of the OTS`s Materials Development Program, was developed to meet the ceramic technology requirements of the OTS`s automotive technology programs. Significant accomplishments in fabricating ceramic components for the USDOE and NASA advanced heat engine programs have provided evidence that the operation of ceramic parts in high-temperature engine environments is feasible. These programs have also demonstrated that additional research is needed in materials and processing development, design methodology, and data base and life prediction before industry will have a sufficient technology base from which to produce reliable cost-effective ceramic engine components commercially. A five-year project plan was developed with extensive input from private industry. In July 1990 the original plan was updated through the estimated completion of development in 1993. The objective is to develop the industrial technology base required for reliable ceramics for application in advanced automotive heat engines. The project approach includes determining the mechanisms controlling reliability, improving processes for fabricating existing ceramics, developing new materials with increased reliability, and testing these materials in simulated engine environments to confirm reliability. Although this is a generic materials project, the focus is on the structural ceramics for advanced gas turbine and diesel engines, ceramic bearings and attachments, and ceramic coatings for thermal barrier and wear applications in these engines. To facilitate the rapid transfer of this technology to US industry, the major portion of the work is being done in the ceramic industry, with technological support from government laboratories, other industrial laboratories, and universities.

Not Available

1992-03-01T23:59:59.000Z

345

Nuclear Energy Research Initiative (NERI) Program Continuous Fiber Wound Ceramic Composite (CFCC) for Commercial Water Reactor Fuel-Technical Progress Report  

SciTech Connect (OSTI)

Our program began on August 1, 1999. As of January 1, 2000, the progress has been in contracting, materials selection, and test planning. All 3 subcontracts are now in place (McDermott Technologies Inc. for ceramic fabrication, Swales Aerospace for LOCA testing, and Massachusetts Institute of Technology for in Reactor testing). With regard to material selection, we visited McDermott Technologies on December 6, 1999 to discuss the progress on Materials Selection and issues regarding Permeability Reduction in CFCC materials. We are evaluating several options for reducing the permeability of the CFCC materials, including Chemical Vapor Infiltration. McDermott Technologies is approximately two months late on their scheduled delivery to Gamma of Materials Selection reports. They have indicated by letter that they plan to deliver a draft and then final Materials Selection Report to Gamma by January 15 and February 1st, 2000, respectively. With regard to Test Planning, Swales Aerospace is proceeding with engineering the test chamber. The power supply selection for the Kanthal furnace was changed from AC to DC current to simplify equipment and operation. The mechanism for opening the ''sliding door'' on bottom of furnace has been changed from air cylinder to stainless steel spring/cord to provide inherent simplicity and failsafe operation. Alumina tubing for apparatus calibration was obtained from Coors Ceramics; 0.5 x 1/16 foot wall x 16 inches, grade AD-998, 99.8% Al{sub 2}O{sub 3}, density 3.9 gr/cc. This will be cut into 3 inch specimen and very closely matches the expected test specimens from McDermott. Swales and Gamma are currently selecting extension springs from Associated Spring to provide a tension on furnace ''bottom door''. Swales and Gamma are currently evaluating sample of Alumina board from Zircar for the furnace ''door.''

Feinroth, Herbert

2000-01-01T23:59:59.000Z

346

Composite turbine bucket assembly  

DOE Patents [OSTI]

A composite turbine blade assembly includes a ceramic blade including an airfoil portion, a shank portion and an attachment portion; and a transition assembly adapted to attach the ceramic blade to a turbine disk or rotor, the transition assembly including first and second transition components clamped together, trapping said ceramic airfoil therebetween. Interior surfaces of the first and second transition portions are formed to mate with the shank portion and the attachment portion of the ceramic blade, and exterior surfaces of said first and second transition components are formed to include an attachment feature enabling the transition assembly to be attached to the turbine rotor or disk.

Liotta, Gary Charles; Garcia-Crespo, Andres

2014-05-20T23:59:59.000Z

347

Polycrystal model of the mechanical behavior of a Mo-TiC30vol.% metal-ceramic composite using a 3D microstructure map obtained by a dual beam FIB-SEM  

E-Print Network [OSTI]

The mechanical behavior of a Mo-TiC30 vol.% ceramic-metal composite was investigated over a large temperature range (25^{\\circ}C to 700^{\\circ}C). High-energy X-ray tomography was used to reveal the percolation of the hard titanium carbide phase through the composite. Using a polycrystal approach for a two-phase material, finite element simulations were performed on a real 3D aggregate of the material. The 3D microstructure, used as starting configuration for the predictions, was obtained by serial-sectioning in a dual beam Focused Ion Beam (FIB)-Scanning Electron Microscope (SEM) coupled to an Electron Back Scattering Diffraction system (3D EBSD, EBSD tomography). The 3D aggregate consists of a molybdenum matrix and a percolating TiC skeleton. As most BCC metals, the molybdenum matrix phase is characterized by a change in the plasticity mechanisms with temperature. We used a polycrystal model for the BCC material, which was extended to two phases (TiC and Mo). The model parameters of the matrix were determin...

Cédat, Denis; Rey, Colette; Raabe, Dierk; 10.1016/actamat.2011.11.55

2013-01-01T23:59:59.000Z

348

Ceramic gas turbine shroud  

DOE Patents [OSTI]

An example gas turbine engine shroud includes a first annular ceramic wall having an inner side for resisting high temperature turbine engine gasses and an outer side with a plurality of radial slots. A second annular metallic wall is positioned radially outwardly of and enclosing the first annular ceramic wall and has a plurality of tabs in communication with the slot of the first annular ceramic wall. The tabs of the second annular metallic wall and slots of the first annular ceramic wall are in communication such that the first annular ceramic wall and second annular metallic wall are affixed.

Shi, Jun; Green, Kevin E.

2014-07-22T23:59:59.000Z

349

Silicon nitride/silicon carbide composite powders  

DOE Patents [OSTI]

Prepare silicon nitride-silicon carbide composite powders by carbothermal reduction of crystalline silica powder, carbon powder and, optionally, crystalline silicon nitride powder. The crystalline silicon carbide portion of the composite powders has a mean number diameter less than about 700 nanometers and contains nitrogen. The composite powders may be used to prepare sintered ceramic bodies and self-reinforced silicon nitride ceramic bodies.

Dunmead, Stephen D. (Midland, MI); Weimer, Alan W. (Midland, MI); Carroll, Daniel F. (Midland, MI); Eisman, Glenn A. (Midland, MI); Cochran, Gene A. (Midland, MI); Susnitzky, David W. (Midland, MI); Beaman, Donald R. (Midland, MI); Nilsen, Kevin J. (Midland, MI)

1996-06-11T23:59:59.000Z

350

Strong, Tough Ceramics Containing Microscopic Reinforcements: Tailoring In-Situ Reinforced Silicon Nitride Ceramics  

SciTech Connect (OSTI)

Ceramics with their hardness, chemical stability, and refractoriness could be used to design more efficient energy generation and conversion systems as well as numerous other applications. However, we have needed to develop a fundamental understanding of how to tailor ceramics to improve their performance, especially to overcome their brittle nature. One of the advances in this respect was the incorporation of very strong microscopic rod-like reinforcements in the form of whiskers that serve to hold the ceramic together making it tougher and resistant to fracture. This microscopic reinforcement approach has a number of features that are similar to continuous fiber-reinforced ceramics; however, some of the details are modified. For instance, the strengths of the microscopic reinforcements must be higher as they typically have much stronger interfaces. For instance, single crystal silicon carbide whiskers can have tensile strengths in excess of {ge}7 GPa or >2 times that of continuous fibers. Furthermore, reinforcement pullout is limited to lengths of a few microns in the case of microscopic reinforcement due as much to the higher interfacial shear resistance as to the limit of the reinforcement lengths. On the other hand, the microscopic reinforcement approach can be generated in-situ during the processing of ceramics. A remarkable example of this is found in silicon nitride ceramics where elongated rod-like shape grains can be formed when the ceramic is fired at elevated temperatures to form a dense component.

Becher, P.F.

1999-06-27T23:59:59.000Z

351

Ceramic Technology Project database: September 1993 summary report  

SciTech Connect (OSTI)

Data presented in this report represent an intense effort to improve processing methods, testing methods, and general mechanical properties of candidate ceramics for use in advanced heat engines. Materials discussed include GN-10, GS-44, GTE PY6, NT-154, NT-164, sintered-reaction-bonded silicon nitrides, silicon nitride combined with rare-earth oxides, NT-230, Hexoloy SX-G1, Dow Corning`s {beta}-Si{sub 3}N{sub 4}, and a few whisker-reinforced ceramic composites. Information in this report was taken from the project`s semiannual and bimonthly progress reports and from final reports summarizing the results of individual studies. Test results are presented in tabular form and in graphs. All data, including test rig descriptions and material characterizations, are stored in the CTP database and are available to all project participants on request. Objective of this report is to make available the test results from these studies but not to draw conclusions from those data.

Keyes, B.L.P.

1994-01-01T23:59:59.000Z

352

Nanotube fracture during the failure of carbon nanotube/ alumina composites  

E-Print Network [OSTI]

-based ceramic composites, leading to improved fracture toughness. � 2011 Elsevier Ltd. All rights reserved. 1 problem, incorporation of particulates, flakes and short/long fibers into ceramics matrix, as a second, chemical and electrical properties [3­7], motivating their use in ceramic composite materials as a fibrous

353

Oxygen Transport Ceramic Membranes  

SciTech Connect (OSTI)

In the present quarter, experiments are presented on ceramic/metal interactions of Zirconia/ Ni-B-Si system and with a thin Ti coating deposited on zirconia surface. Existing facilities were modified for evaluation of environmental assisted slow crack growth and creep in flexural mode. Processing of perovskites of LSC, LSF and LSCF composition were continued for evaluation of mechanical properties as a function of environment. These studies in parallel to those on the LSFCO composition is expect to yield important information on questions such as the role of cation segregation and the stability of the perovskite structure on crack initiation vs. crack growth. Studies have been continued on the La{sub 1-x}Sr{sub x}FeO{sub 3-d} composition using neutron diffraction and TGA studies. A transition from p-type to n-type of conductor was observed at relative low pO{sub 2}, at which the majority carriers changed from the holes to electrons because of the valence state decreases in Fe due to the further loss of oxygen. Investigation on the thermodynamic properties of the membrane materials are continued to develop a complete model for the membrane transport. Data obtained at 850 C show that the stoichiometry in La{sub 0.2}Sr{sub 0.8}Fe{sub 0.8}Cr{sub 0.2}O{sub 3-x} vary from {approx}2.85 to 2.6 over the pressure range studied. From the stoichiometry a lower limit of 2.6 corresponding to the reduction of all Fe{sup 4+} to Fe{sup 3+} and no reduction of Cr{sup 3+} is expected.

S. Bandopadhyay; N. Nagabhushana

2003-08-07T23:59:59.000Z

354

New ceramics containing dispersants for improved fracture toughness  

DOE Patents [OSTI]

The invention is a ceramic composition containing a new class of dispersant for hindering crack propagation by means of one or more energy-dissipative mechanisms. The composition is composed of a ceramic matrix with dispersed particles of a transformation-prone rare-earth niobate, tantalate or mixtures of these with each other and/or with a rare-earth vanadate. The dispersants, having a generic composition tRBO/sub 4/, where R is a rare-earth element, B if Nb or Ta and O is oxygen, are mixed in powder form with a powder of the matrix ceramic and sintered to produce a ceramic form or body. The crack-hindering mechanisms operates to provide improved performance over a wide range of temperature and operating conditions.

Nevitt, M.V.; Aldred, A.T.; Chan, Sai-Kit

1985-07-01T23:59:59.000Z

355

12 American Ceramic Society Bulletin, Vol. 85, No. 7 Nanotube `Sandwiches' Could  

E-Print Network [OSTI]

12 American Ceramic Society Bulletin, Vol. 85, No. 7 Nanotube `Sandwiches' Could Lead to Better Composites Reinforced composite fabrics made from woven ceramic fibers have been used for decades. The fabric layers are infiltrated with a high-temperature epoxy matrix, and then several layers of cloth

Azad, Abdul-Majeed

356

Thermal resistance of bridged cracks in fiber-reinforced ceramic John Dryden  

E-Print Network [OSTI]

-reinforced ceramic composites obtain high toughness is through the de- velopment of multiple matrix cracksThermal resistance of bridged cracks in fiber-reinforced ceramic composites John Dryden Department November 2000; accepted for publication 16 January 2001 The thermal resistance of a bridged matrix crack

Zok, Frank

357

Advanced Fibers and Nanocomposites Georgia Tech has a rich tradition of excellence in composite materials and structures, and is an  

E-Print Network [OSTI]

-performance composites. Built on a deep understanding of constituent materials and how they interact in fabrication nanomanufacturing, integrated computational composite materials engineering, and smart composites through integrated carbon nanotube buckypaper, smart composites with embedded, non-invasive strain gauges and temperature

Li, Mo

358

SURFACES AND INTERFACES IN CERAMIC AND CERAMIC-METAL SYSTEMS  

E-Print Network [OSTI]

contained within the ceramic matrix of a-Alz03 and (Fe,Mn,layers compared to the ceramic matrix. An additional O.OSpm

,

2013-01-01T23:59:59.000Z

359

Pumpable/injectable phosphate-bonded ceramics  

SciTech Connect (OSTI)

A pumpable ceramic composition is provided comprising an inorganic oxide, potassium phosphate, and an oxide coating material. Also provided is a method for preparing pumpable ceramic-based waste forms comprising selecting inorganic oxides based on solubility, surface area and morphology criteria; mixing the selected oxides with phosphate solution and waste to form a first mixture; combining an additive to the first mixture to create a second mixture; adding water to the second mixture to create a reactive mixture; homogenizing the reactive mixture; and allowing the reactive mixture to cure.

Singh, Dileep (Naperville, IL); Wagh, Arun S. (Orland Park, IL); Perry, Lamar (Fontana, CA); Jeong, Seung-Young (Justice, IL)

2001-01-01T23:59:59.000Z

360

Ceramic Electron Multiplier  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

The Ceramic Electron Multipliers (CEM) is a compact, robust, linear and fast multi-channel electron multiplier. The Multi Layer Ceramic Technique (MLCT) allows to build metallic dynodes inside a compact ceramic block. The activation of the metallic dynodes enhances their secondary electron emission (SEE). The CEM can be used in multi-channel photomultipliers, multi-channel light intensifiers, ion detection, spectroscopy, analysis of time of flight events, particle detection or Cherenkov imaging detectors. (auth)

Comby, G.

1996-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "advanced ceramic composites" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Development of an Innovative High-Thermal Conductivity UO2 Ceramic Composites Fuel Pellets with Carbon Nano-Tubes Using Spark Plasma Sintering  

SciTech Connect (OSTI)

Uranium dioxide (UO2) is the most common fuel material in commercial nuclear power reactors. Despite its numerous advantages such as high melting point, good high-temperature stability, good chemical compatibility with cladding and coolant, and resistance to radiation, it suffers from low thermal conductivity that can result in large temperature gradients within the UO2 fuel pellet, causing it to crack and release fission gases. Thermal swelling of the pellets also limits the lifetime of UO2 fuel in the reactor. To mitigate these problems, we propose to develop novel UO2 fuel with uniformly distributed carbon nanotubes (CNTs) that can provide high-conductivity thermal pathways and can eliminate fuel cracking and fission gas release due to high temperatures. CNTs have been investigated extensively for the past decade to explore their unique physical properties and many potential applications. CNTs have high thermal conductivity (6600 W/mK for an individual single- walled CNT and >3000 W/mK for an individual multi-walled CNT) and high temperature stability up to 2800°C in vacuum and about 750°C in air. These properties make them attractive candidates in preparing nano-composites with new functional properties. The objective of the proposed research is to develop high thermal conductivity of UO2–CNT composites without affecting the neutronic property of UO2 significantly. The concept of this goal is to utilize a rapid sintering method (5–15 min) called spark plasma sintering (SPS) in which a mixture of CNTs and UO2 powder are used to make composites with different volume fractions of CNTs. Incorporation of these nanoscale materials plays a fundamentally critical role in controlling the performance and stability of UO2 fuel. We will use a novel in situ growth process to grow CNTs on UO2 particles for rapid sintering and develop UO2-CNT composites. This method is expected to provide a uniform distribution of CNTs at various volume fractions so that a high thermally conductive UO2-CNT composite is obtained with a minimal volume fraction of CNTs. The mixtures are sintered in the SPS facility at a range of temperatures, pressures, and time durations so as to identify the optimal processing conditions to obtain the desired microstructure of sintered UO2-CNT pellets. The second objective of the proposed work is to identify the optimal volume fraction of CNTs in the microstructure of the composites that provides the desired high thermal conductivity yet retaining the mechanical strength required for efficient function as a reactor fuel. We will systematically study the resulting microstructure (grain size, porosity, distribution of CNTs, etc.) obtained at various SPS processing conditions using optical microscopy, scanning electron microscopy (SEM), and transmission electron microscope (TEM). We will conduct indentation hardness measurements and uniaxial strength measurements as a function of volume fraction of CNTs to determine the mechanical strength and compare them to the properties of UO2. The fracture surfaces will be studied to determine the fracture characteristics that may relate to the observed cracking during service. Finally, we will perform thermal conductivity measurements on all the composites up to 1000° C. This study will relate the microstructure, mechanical properties, and thermal properties at various volume fractions of CNTs. The overall intent is to identify optimal processing conditions that will provide a well-consolidated compact with optimal microstructure and thermo-mechanical properties. The deliverables include: (1) fully characterized UO2-CNT composite with optimal CNT volume fraction and high thermal conductivity and (2) processing conditions for production of UO2-CNT composite pellets using SPS method.

Subhash, Ghatu; Wu, Kuang-Hsi; Tulenko, James

2014-03-10T23:59:59.000Z

362

Method of sintering ceramic materials  

DOE Patents [OSTI]

A method for sintering ceramic materials is described. A ceramic article is coated with layers of protective coatings such as boron nitride, graphite foil, and niobium. The coated ceramic article is embedded in a container containing refractory metal oxide granules and placed within a microwave oven. The ceramic article is heated by microwave energy to a temperature sufficient to sinter the ceramic article to form a densified ceramic article having a density equal to or greater than 90% of theoretical density. 2 figs.

Holcombe, C.E.; Dykes, N.L.

1992-11-17T23:59:59.000Z

363

Silicon nitride/silicon carbide composite densified materials prepared using composite powders  

DOE Patents [OSTI]

Prepare silicon nitride-silicon carbide composite powders by carbothermal reduction of crystalline silica powder, carbon powder and, optionally, crystalline silicon nitride powder. The crystalline silicon carbide portion of the composite powders has a mean number diameter less than about 700 nanometers and contains nitrogen. The composite powders may be used to prepare sintered ceramic bodies and self-reinforced silicon nitride ceramic bodies.

Dunmead, S.D.; Weimer, A.W.; Carroll, D.F.; Eisman, G.A.; Cochran, G.A.; Susnitzky, D.W.; Beaman, D.R.; Nilsen, K.J.

1997-07-01T23:59:59.000Z

364

Emergent process methods for high-technology ceramics  

SciTech Connect (OSTI)

The present conference covers colloidal processing of advanced ceramics, novel power-forming and powder-processing methods, the derivation of ceramics by polymer processing, chemical vapor deposition techniques, ion beam deposition methods, the laser and ion beam modification of surfaces, hot isostatic pressing and dynamic compaction, shock conditioning and subsequent densification of ceramics, and very high pressure processing methods. Specific attention is given to the preparation of shaped glasses by the sol-gel method, the synthesis of powders and thin films by laser-induced gas phase reactions, the plasma sintering of ceramics, laser chemical vapor deposition, the microstructure and mechanical properties of ion-implanted ceramics, a computer simulation of dynamic compaction, shock-induced modification of inorganic powders, and diamond anvil technology.

Davis, R.F.; Palmour, H. III; Porter, R.L.

1984-01-01T23:59:59.000Z

365

Comptes Rendus des JNC 17 -Poitiers 2011 Modlisation du comportement de composite matrice cramique sous  

E-Print Network [OSTI]

céramique sous sollicitation de fatigue Modeling of ceramic matrix composite behavior under fatigue loading to determine the lifetime in fatigue of a ceramic matrix composite. This approach is done by coupling a very important role in the lifetime of the composite. Under oxidizing atmosphere, the ceramic matrix

Boyer, Edmond

366

Thermophysical and Mechanical Properties of SiC/SiC Composites (5/28/98 draft)  

E-Print Network [OSTI]

(unirradiated) #12;Most of the available data on ceramic matrix composites have been generated using flexural for the generation of an engineering data base. Ceramic matrix composites are engineered to produce a moderate amount, is comparable to the composite ultimate tensile strength. A more appropriate ÒyieldÓ strength for ceramic matrix

California at Los Angeles, University of

367

Structural and magnetic heterogeneities, phase transitions, and magnetoresistance and magnetoresonance properties of the composition ceramic La{sub 0.7}Pb{sub 0.3-x}Sn{sub x}MnO{sub 3}  

SciTech Connect (OSTI)

The La{sub 0.7}Pb{sub 0.3-x}Sn{sub x}MnO{sub 3} composition ceramic is studied by X-ray diffraction, resistive, magnetic, electron-microscopic, magnetoresistance, and NMR ({sup 55}Mn, {sup 139}La) methods. The substitution of tin for lead results in structural phase separation into the basic perovskite (R3-bar c) and spinell (Fd3m), phases: La{sub 0.7}Pb{sub 0.3-x}Sn{sub x}MnO{sub 3} {yields} La{sub 0.7-x}Pb{sub 0.3-x}MnO{sub 3} + 0.5xLa{sub 2}Sn{sub 2}O{sub 7}. Changes in the lattice parameter of the basic perovskite R3-bar c structure, the electrical resistivity, and the magnetic and magnetoresistance properties are caused by changes in the composition and content of a conducting perovskite ferromagnetic phase, the Mn{sup 3+}/Mn{sup 4+} ratio, and the imperfection of vacancy and cluster types. An in-plane nanostructured cluster is formed by Mn{sup 2+} ions located in distorted A-positions. The detected anomalous magnetic hysteresis is induced by the appearance of a unidirectional exchange anisotropy at the boundary of an in-plane antifer-romagnetic cluster coherently joined with a ferromagnetic matrix structure. The broad asymmetric NMR spectra of {sup 55}Mn and {sup 139}La indicate a high-frequency Mn{sup 3+} {r_reversible} Mn{sup 4+} superexchange and a nonuniform distribution of ions and defects. The constructed phase diagram characterizes a strong relation between the magnetic and transport properties in rare-earth manganites.

Pashchenko, V. P., E-mail: alpash@mail.ru; Pashchenko, A. V.; Prokopenko, V. K.; Revenko, Yu. F.; Burkhovetskii, V. V.; Shemyakov, A. A. [National Academy of Sciences of Ukraine, Galkin Institute for Physics and Engineering (Ukraine); Sil'cheva, A. G. [Luhansk Taras Shevchenko National University (Ukraine); Levchenko, G. G. [National Academy of Sciences of Ukraine, Galkin Institute for Physics and Engineering (Ukraine)

2012-03-15T23:59:59.000Z

368

Original article Flat ceramic membranes  

E-Print Network [OSTI]

membranes. The orig- inal intellectual concept is protected by two international patents. Strategically of investment and functioning costs while keeping the interest of ceramics. ceramic membrane / plate / tubular

Paris-Sud XI, Université de

369

Oxygen Transport Ceramic Membranes  

SciTech Connect (OSTI)

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. In the previous research, the reference point of oxygen occupancy was determined and verified. In the current research, the oxygen occupancy was investigated at 1200 C as a function of oxygen activity and compared with that at 1000 C. The cause of bumps at about 200 C was also investigated by using different heating and cooling rates during TGA. The fracture toughness of LSFT and dual phase membranes at room temperature is an important mechanical property. Vicker's indentation method was used to evaluate this toughness. Through this technique, a K{sub Ic} (Mode-I Fracture Toughness) value is attained by means of semi-empirical correlations between the indentation load and the length of the cracks emanating from the corresponding Vickers indentation impression. In the present investigation, crack propagation behavior was extensively analyzed in order to understand the strengthening mechanisms involved in the non-transforming La based ceramic composites. Cracks were generated using Vicker's indenter and used to identify and evaluate the toughening mechanisms involved. Preliminary results of an electron microscopy study of the origin of the slow kinetics on reduction of ferrites have been obtained. The slow kinetics appear to be related to a non-equilibrium reduction pathway that initially results in the formation of iron particles. At long times, equilibrium can be reestablished with recovery of the perovskite phase. Modeling of the isotopic transients on operating membranes (LSCrF-2828 at 900 C) and a ''frozen'' isotope profile have been analyzed in conjunction with a 1-D model to reveal the gradient in oxygen diffusivity through the membrane under conditions of high chemical gradients.

S. Bandopadhyay; T. Nithyanantham; X.-D Zhou; Y-W. Sin; H.U. Anderson; Alan Jacobson; C.A. Mims

2005-08-01T23:59:59.000Z

370

Cermet composite thermal spray coatings for erosion and corrosion protection in combustion environments of advanced coal-fired boilers. Semiannual technical progress report, August 14, 1996--January 14, 1997  

SciTech Connect (OSTI)

Research is presently being conducted to determine the optimum ceramic/metal combination in thermally sprayed metal matrix composite coatings for erosion and corrosion resistance in new coal-fired boilers. The research will be accomplished by producing model cermet composites using powder metallurgy and electrodeposition methods in which the effect of ceramic/metal combination for the erosion and corrosion resistance will be determined. These results will provide the basis for determining the optimum hard phase constituent size and volume percent in thermal spray coatings. Thermal spray coatings will be applied by our industrial sponsor and tested in our erosion and corrosion laboratories. In the first six months of this project, bulk powder processed Ni-Al{sub 2}O{sub 3} composites were produced at Idaho National Engineering Laboratory. The results of microstructural characterization of these alloys were presented in the first semiannual report. The composite samples contained 0, 21, 27, 37, and 45 volume percent Al{sub 2}O{sub 3} with an average particle size of 12 um. An increase in the volume fraction of alumina in the nickel matrix from 0 to 45% led to a significant increase in hardness of these composites.

Levin, B.F.; DuPont, J.N.; Marder, A.R.

1997-02-01T23:59:59.000Z

371

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect (OSTI)

This is the fifth quarterly report on a new study to develop a ceramic membrane/metal joint. Results of wetting experiments on commercially available Nickel based brazing alloys on perovskite surfaces are described. Additionally, experimental and numerical investigations on the strength of concentric ceramic/metal joints are presented.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2001-02-01T23:59:59.000Z

372

Compatibility of selected ceramics with steam-methane reformer environments  

SciTech Connect (OSTI)

Conventional steam reforming of methane to synthesis gas (CO and H{sub 2}) hasa conversion efficiency of about 85%. Replacement of metal tubes in the reformer with ceramic tubes offers the potential for operation at temperatures high enough to increase the efficiency to 98-99%. However, the two candidate ceramic materials being given strongest consideration, sintered alpha Si carbide and Si carbide particulate-strengthened alumina, have been shown to react with components of the reformer environment. Extent of degradation as a function of steam partial pressure and exposure time has been studied, and results suggest limits under which these structural ceramics can be used in advanced steam-methane reformers.

Keiser, J.R.; Howell, M. [Oak Ridge National Lab., TN (United States); Williams, J.J.; Rosenberg, R.A. [Stone and Webster Engineering Corp., Boston, MA (United States)

1996-04-01T23:59:59.000Z

373

Ceramic heat exchanger  

DOE Patents [OSTI]

A tube containment system is disclosed. The tube containment system does not significantly reduce heat transfer through the tube wall. The contained tube is internally pressurized, and is formed from a ceramic material having high strength, high thermal conductivity, and good thermal shock resistance. The tube containment system includes at least one ceramic fiber braid material disposed about the internally pressurized tube. The material is disposed about the tube in a predetermined axial spacing arrangement. The ceramic fiber braid is present in an amount sufficient to contain the tube if the tube becomes fractured. The tube containment system can also include a plurality of ceramic ring-shaped structures, in contact with the outer surface of the tube, and positioned between the tube and the ceramic fiber braid material, and/or at least one transducer positioned within tube for reducing the internal volume and, therefore, the energy of any shrapnel resulting from a tube fracture. 6 figs.

LaHaye, P.G.; Rahman, F.H.; Lebeau, T.P.; Severin, B.K.

1998-06-16T23:59:59.000Z

374

Ceramic heat exchanger  

DOE Patents [OSTI]

A tube containment system. The tube containment system does not significantly reduce heat transfer through the tube wall. The contained tube is internally pressurized, and is formed from a ceramic material having high strength, high thermal conductivity, and good thermal shock resistance. The tube containment system includes at least one ceramic fiber braid material disposed about the internally pressurized tube. The material is disposed about the tube in a predetermined axial spacing arrangement. The ceramic fiber braid is present in an amount sufficient to contain the tube if the tube becomes fractured. The tube containment system can also include a plurality of ceramic ring-shaped structures, in contact with the outer surface of the tube, and positioned between the tube and the ceramic fiber braid material, and/or at least one transducer positioned within tube for reducing the internal volume and, therefore, the energy of any shrapnel resulting from a tube fracture.

LaHaye, Paul G. (Kennebunk, ME); Rahman, Faress H. (Portland, ME); Lebeau, Thomas P. E. (Portland, ME); Severin, Barbara K. (Biddeford, ME)

1998-01-01T23:59:59.000Z

375

Mounting for ceramic scroll  

DOE Patents [OSTI]

A mounting for a ceramic scroll on a metal engine block of a gas turbine engine includes a first ceramic ring and a pair of cross key connections between the first ceramic ring, the ceramic scroll, and the engine block. The cross key connections support the scroll on the engine block independent of relative radial thermal growth and for bodily movement toward an annular mounting shoulder on the engine. The scroll has an uninterrupted annular shoulder facing the mounting shoulder on the engine block. A second ceramic ring is captured between mounting shoulder and the uninterrupted shoulder on the scroll when the latter is bodily shifted toward the mouting shoulder to define a gas seal between the scroll and the engine block.

Petty, Jack D. (Indianapolis, IN)

1993-01-01T23:59:59.000Z

376

Materials Development Program: Ceramic Technology Project bibliography, 1984--1992  

SciTech Connect (OSTI)

The Ceramic Technology [for Advanced Heat Engines] Project was begun in 1983 to meet the ceramic materials needs of the companion DOE automotive engine program, the Advanced Gas Turbine (AGT) project, and the Heavy Duty Transport (low-heat-rejection, heavy-duty diesel) project. Goal is to develop an industry technology base for reliable and cost effective ceramics for applications in advanced automotive gas turbine and diesel engines. Research areas were identified following extensive input from industry and academia. Majority of research is done by industry (60%); work is also done at colleges and universities, in-house, and at other national laboratories and government agencies. In the beginning, reliability of ceramic components was the key issue. The reliability issues have largely been met and, at the present time, cost is the driving issue, especially in light of the highly cost-sensitive automotive market. Emphasis of the program has now been shifted toward developing cost-effective ceramic components for high-performance engines in the near-term. This bibliography is a compilation of publications done in conjunction with the Ceramic Technology Project since its beginning. Citations were obtained from reports done by participants in the project. We have tried to limit citations to those published and easily located. The end date of 1992 was selected.

Not Available

1994-03-01T23:59:59.000Z

377

Development of ceramic matrix composites for application in the ceramic technology for Advanced Heat Engines Project: Phase 2a, Development of in-situ toughened silicon nitride. Final report  

SciTech Connect (OSTI)

The objective of this program was to develop a net shape forming process for an in-situ reinforced Si{sub 3}N{sub 4} (AS-700). AS-700 was initially developed using cold isostatic pressing (CIP) of alcohol milled powders. The CIP`ed AS-700 material exhibited a moderate strength (690 MPa) and high toughness (9 MPa{radical}m) at room temperature. In addition to net-shape process development, optimization of AS-700 properties was also investigated through the refinement of densification processes, and evaluation of the effect of Si{sub 3}N{sub 4} powder properties on resulting microstructure and mechanical properties. Slip casting was chosen as the net-shape forming process. A slip casting process was successfully developed for forming green parts ranging from thin plates to thick cylinders, and to large complex shaped turbine rotors. The densification cycle was optimized to achieve full density parts without any cracks or warpage, and with comparable properties and microstructure to the CIP`ed baseline AS-700 material. The evaluation of six (6) alternate Si{sub 3}N{sub 4} powders indicated that Si{sub 3}N{sub 4} powders have a very strong influence on the development of resulting AS-700 in-situ microstructures and mechanical properties. The AS-700 slip casting process and optimized densification process were then combined and a number of test specimens were fabricated. The mechanical properties and microstructure of the optimized slip cast AS-700 Si{sub 3}N{sub 4} were then fully characterized. The key property values are: 695 MPa at room temperature, 446 MPa at 1370{degree}C flexural strengths and 8.25 MPa{radical}m toughness.

Pollinger, J.; Newson, D.; Yeh, H.; Solidum, E. [Allied-Signal Aerospace Co., Torrance, CA (United States). Garrett Ceramic Components Div.; Yamanis, J.; Behi, M.; Li, C.W.; Whalen, P. [Allied-Signal, Inc., Morristown, NJ (United States)

1992-06-01T23:59:59.000Z

378

Oxygen Transport Ceramic Membranes  

SciTech Connect (OSTI)

The present quarterly report describes some of the initial studies on newer compositions and also includes newer approaches to address various materials issues such as in metal-ceramic sealing. The current quarter's research has also focused on developing a comprehensive reliability model for predicting the structural behavior of the membranes in realistic conditions. In parallel to industry provided compositions, models membranes have been evaluated in varying environment. Of importance is the behavior of flaws and generation of new flaws aiding in fracture. Fracture mechanics parameters such as crack tip stresses are generated to characterize the influence of environment. Room temperature slow crack growth studies have also been initiated in industry provided compositions. The electrical conductivity and defect chemistry of an A site deficient compound (La{sub 0.55}Sr{sub 0.35}FeO{sub 3}) was studied. A higher conductivity was observed for La{sub 0.55}Sr{sub 0.35}FeO{sub 3} than that of La{sub 0.60}Sr{sub 0.40}FeO{sub 3} and La{sub 0.80}Sr{sub 0.20}FeO{sub 3}. Defect chemistry analysis showed that it was primarily contributed by a higher carrier concentration in La{sub 0.55}Sr{sub 0.35}FeO{sub 3}. Moreover, the ability for oxygen vacancy generation is much higher in La{sub 0.55}Sr{sub 0.35}FeO{sub 3} as well, which indicates a lower bonding strength between Fe-O and a possible higher catalytic activity for La{sub 0.55}Sr{sub 0.35}FeO{sub 3}. The program continued to investigate the thermodynamic properties (stability and phase separation behavior) and total conductivity of prototype membrane materials. The data are needed together with the kinetic information to develop a complete model for the membrane transport. Previous report listed initial measurements on a sample of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-x} prepared in-house by Praxair. Subsequently, a second sample of powder from a larger batch of sample were characterized and compared with the results from the previous batch.

S. Bandopadhyay; N. Nagabhushana; Thomas W. Eagar; Harold R. Larson; Raymundo Arroyave; X.-D Zhou; Y.-W. Shin; H.U. Anderson; Nigel Browning; Alan Jacobson; C.A. Mims

2003-11-01T23:59:59.000Z

379

Improving the dielectric and piezoelectric properties of screen-printed Low temperature PZT/polymer composite  

E-Print Network [OSTI]

of piezoelectric ceramic powders and a polymer matrix. The polymer used can itself be piezoelectric [3 materials, ceramics, polymers and composites. Ceramic piezoelectric materials (e.g. lead zirconate titanate. This porosity increases when increasing the weight percentages of the ceramic phase above 50% [7]. It occurs

380

Development of nondestructive evaluation methods for ceramic coatings.  

SciTech Connect (OSTI)

Various nondestructive evaluation (NDE) technologies are being developed to study the use of ceramic coatings on components in the hot-gas path of advanced low-emission gas-fired turbines. The types of ceramic coatings include thermal barrier coatings (TBCs) and environmental barrier coatings (EBCs). TBCs are under development for vanes, blades, and combustor liners to allow hotter gas-path temperatures, and EBCs are under development to reduce environmental damage to high-temperature components made of ceramic matrix composites. The NDE methods will be used to (a) provide data to assess the reliability of new coating application processes, (b) identify defective components that could cause unscheduled outages, (c) track growth rates of defects during component use in engines, and (d) allow rational judgment for replace/repair/re-use decisions regarding components. Advances in TBC application, both electron beam-physical vapor deposition (EB-PVD) and air plasma spraying (APS), are allowing higher temperatures in the hot-gas path. However, as TBCs become ''prime reliant,'' their condition at scheduled or unscheduled outages must be known. NDE methods are under development to assess the condition of the TBC for pre-spall conditions. EB-PVD test samples with up to 70 thermal cycles have been studied by a newly developed method involving polarized laser back-scatter NDE. Results suggest a correlation between the NDE laser data and the TBC/bond-coat topography. This finding is important because several theories directed toward understanding the pre-spall condition suggest that the topography in the thermally grown oxide layer changes significantly as a function of the number of thermal cycles. Tests have also been conducted with this NDE method on APS TBCs. Results suggest that the pre-spall condition is detected for these coatings. One-sided, high-speed thermal imaging also has shown promise for NDE of APS coatings. Testing of SiC/SiC composites for combustor liners has demonstrated that environmental EBCs are required to reduce oxidation-induced recession rates. NDE technologies, primarily one-sided and through-thickness thermal imaging, are under development to detect delaminations and degradation of EBCs. Recent results have demonstrated that NDE thermal image data correctly detected pre-spall regions of a barium-strontium-alumino-silicate coating on melt-infiltrated SiC/SiC. The NDE data were verified with field test data from a combustor liner in a 4.5 MW(e) natural-gas-fired turbine. The shape of the spalled EBC region and the growth of the spalled EBC region after various engine run times were correlated with boroscope image data from field tests. An effort has recently been started to address NDE development for oxide/oxide ceramic composites with an EBC. We will discuss the NDE methods under development for TBCs, recent NDE test results from thermally cycled TBCs, NDE results from EBCs on SiC/SiC, and the new effort directed toward oxide/oxide materials.

Ellingson, W. A.; Deemer, C.; Sun, J. G.; Erdman, S.; Muliere, D.; Wheeler, B.

2002-04-29T23:59:59.000Z

Note: This page contains sample records for the topic "advanced ceramic composites" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

High pressure ceramic joint  

DOE Patents [OSTI]

Many recuperators have components which react to corrosive gases and are used in applications where the donor fluid includes highly corrosive gases. These recuperators have suffered reduced life, increased service or maintenance, and resulted in increased cost. The present joint when used with recuperators increases the use of ceramic components which do not react to highly corrosive gases. Thus, the present joint used with the present recuperator increases the life, reduces the service and maintenance, and reduces the increased cost associated with corrosive action of components used to manufacture recuperators. The present joint is comprised of a first ceramic member, a second ceramic member, a mechanical locking device having a groove defined in one of the first ceramic member and the second ceramic member. The joint and the mechanical locking device is further comprised of a refractory material disposed in the groove and contacting the first ceramic member and the second ceramic member. The present joint mechanically provides a high strength load bearing joint having good thermal cycling characteristics, good resistance to a corrosive environment and good steady state strength at elevated temperatures. 4 figures.

Ward, M.E.; Harkins, B.D.

1993-11-30T23:59:59.000Z

382

High pressure ceramic joint  

DOE Patents [OSTI]

Many recuperators have components which react to corrosive gases and are used in applications where the donor fluid includes highly corrosive gases. These recuperators have suffered reduced life, increased service or maintenance, and resulted in increased cost. The present joint when used with recuperators increases the use of ceramic components which do not react to highly corrosive gases. Thus, the present joint used with the present recuperator increases the life, reduces the service and maintenance, and reduces the increased cost associated with corrosive action of components used to manufacture recuperators. The present joint is comprised of a first ceramic member, a second ceramic member, a mechanical locking device having a groove defined in one of the first ceramic member and the second ceramic member. The joint and the mechanical locking device is further comprised of a refractory material disposed in the groove and contacting the first ceramic member and the second ceramic member. The present joint mechanically provides a high strength load bearing joint having good thermal cycling characteristics, good resistance to a corrosive environment and good steady state strength at elevated temperatures.

Ward, Michael E. (Poway, CA); Harkins, Bruce D. (San Diego, CA)

1993-01-01T23:59:59.000Z

383

Method of processing ``BPS`` glass ceramic and seals made therewith  

DOE Patents [OSTI]

A glass ceramic composition, a glass ceramic-to-metal seal, and more specifically a hermetic glass ceramic-to-metal seal prepared by subjecting a glass composition comprising, by weight percent, SiO{sub 2} (65--80%), LiO{sub 2} (8--16%), Al{sub 2}O{sub 3} (2--8%), K{sub 2}O (1--8%), P{sub 2}O{sub 5} (1--5%), B{sub 2}O{sub 3} (0.5--7%), and ZnO (0--5%) to the following processing steps: (1) heating the glass composition in a belt furnace to a temperature sufficient to melt the glass and crystallize lithium phosphate, (2) holding at a temperature and for a time sufficient to create cristobalite nuclei, (3) cooling at a controlled rate and to a temperature to cause crystallization of lithium silicates and growth of cristobalite, and (4) still further cooling in stages to ambient temperature. This process produces a glass ceramic whose high coefficient of thermal expansion (up to 200{times}10{sup {minus}7} in/in/C) permits the fabrication of glass ceramic-to-metal seals, and particularly hermetic glass ceramic seals to nickel-based and stainless steel alloys and copper. 5 figs.

Reed, S.T.; Stone, R.G.; McCollister, H.L.; Wengert, P.R.

1998-10-13T23:59:59.000Z

384

Method of processing "BPS" glass ceramic and seals made therewith  

DOE Patents [OSTI]

A glass ceramic composition, a glass ceramic-to-metal seal, and more specifically a hermetic glass ceramic-to-metal seal prepared by subjecting a glass composition comprising, by weight percent, SiO.sub.2 (65-80%), LiO.sub.2 (8-16%), Al.sub.2 O.sub.3 (2-8%), K.sub.2 O (1-8%), P.sub.2 O.sub.5 (1-5%), B.sub.2 O.sub.3 (0.5-7%), and ZnO (0-5%) to the following processing steps: 1) heating the glass composition in a belt furnace to a temperature sufficient to melt the glass and crystallize lithium phosphate, 2) holding at a temperature and for a time sufficient to create cristobalite nuclei, 3) cooling at a controlled rate and to a temperature to cause crystallization of lithium silicates and growth of cristobalite, and 4) still further cooling in stages to ambient temperature. This process produces a glass ceramic whose high coefficient of thermal expansion (up to 200.times.10.sup.-7 in/in/.degree.C.) permits the fabrication of glass ceramic-to-metal seals, and particularly hermetic glass ceramic seals to nickel-based and stainless steel alloys and copper.

Reed, Scott T. (Albuquerque, NM); Stone, Ronald G. (Albuquerque, NM); McCollister, Howard L. (Albuquerque, NM); Wengert, deceased, Paul R. (late of Albuquerque, NM)

1998-01-01T23:59:59.000Z

385

Thermal Conductivity of Polycrystalline Semiconductors and Ceramics  

E-Print Network [OSTI]

semiconductors and ceramics with desired thermalthermal conductivity of several polycrystalline semiconductors and ceramics,Thermal Conductivity of Polycrystalline Semiconductors and Ceramics

Wang, Zhaojie

2012-01-01T23:59:59.000Z

386

ALS Ceramics Materials Research Advances Engine Performance  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert SouthwestTechnologies |November 2011Astudies smart sensors andScienceALSALSALSALSALSALS

387

ALS Ceramics Materials Research Advances Engine Performance  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert SouthwestTechnologies |November 2011Astudies smart sensors

388

ALS Ceramics Materials Research Advances Engine Performance  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered‰PNGExperience4AJ01) (See95TI07)Operations During theALS CapabilitiesALSALSALSALSALS

389

ALS Ceramics Materials Research Advances Engine Performance  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered‰PNGExperience4AJ01) (See95TI07)Operations During theALS

390

Ceramic coating system or water oxidation environments  

DOE Patents [OSTI]

A process for water oxidation of combustible materials in which during at least a part of the oxidation corrosive material is present and makes contact with at least a portion of the apparatus over a contact area on the apparatus. At least a portion of the contact surface area comprises titanium dioxide coated onto a titanium metal substrate. Such ceramic composites have been found to be highly resistant to environments encountered in the process of supercritical water oxidation. Such environments typically contain greater than 50 mole percent water, together with oxygen, carbon dioxide, and a wide range of acids, bases, and salts. Pressures are typically about 27.5 to about 1000 bar while temperatures range as high as 700.degree. C. The ceramic composites are also resistant to degradation mechanisms caused by thermal stresses.

Hong, Glenn T. (Tewksbury, MA)

1996-01-01T23:59:59.000Z

391

Microstructure and characteristics of the metalceramic composite (MgCa-HA/TCP) fabricated by liquid metal infiltration  

E-Print Network [OSTI]

in calcium phosphate bioceramics. Recently metal matrix composites (MMC), consisting of an adequate ceramicMicrostructure and characteristics of the metal­ceramic composite (MgCa-HA/TCP) fabricated and characteristics of the metal­ ceramic composite (MgCa-HA/TCP) fabricated by liquid metal infiltration. J Biomed

Zheng, Yufeng

392

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect (OSTI)

This report covers the following tasks: Task 1--Design, fabricate and evaluate ceramic to metal seals based on graded ceramic powder/metal braze joints; Task 2--Evaluate the effect of defect configuration on ceramic membrane conductivity and long term chemical and structural stability; Task 3--Determine materials mechanical properties under conditions of high temperatures and reactive atmospheres; Task 4--Evaluate phase stability and thermal expansion of candidate perovskite membranes and develop techniques to support these materials on porous metal structures; Task 5--Assess the microstructure of membrane materials to evaluate the effects of vacancy-impurity association, defect clusters, and vacancy-dopant association on the membrane performance and stability; and Task 6--Measure kinetics of oxygen uptake and transport in ceramic membrane materials under commercially relevant conditions using isotope labeling techniques.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2002-04-01T23:59:59.000Z

393

Light emitting ceramic device  

DOE Patents [OSTI]

A light-emitting ceramic based panel, hereafter termed "electroceramescent" panel, is herein claimed. The electroceramescent panel is formed on a substrate providing mechanical support as well as serving as the base electrode for the device. One or more semiconductive ceramic layers directly overlay the substrate, and electrical conductivity and ionic diffusion are controlled. Light emitting regions overlay the semiconductive ceramic layers, and said regions consist sequentially of a layer of a ceramic insulation layer and an electroluminescent layer, comprised of doped phosphors or the equivalent. One or more conductive top electrode layers having optically transmissive areas overlay the light emitting regions, and a multi-layered top barrier cover comprising one or more optically transmissive non-combustible insulation layers overlay said top electrode regions.

Valentine, Paul; Edwards, Doreen D.; Walker, Jr., William John; Slack, Lyle H.; Brown, Wayne Douglas; Osborne, Cathy; Norton, Michael; Begley, Richard

2010-05-18T23:59:59.000Z

394

Ceramic stationary gas turbine development program -- Fifth annual summary  

SciTech Connect (OSTI)

A program is being performed under the sponsorship of the US Department of Energy, Office of Industrial Technologies, to improve the performance of stationary gas turbines in cogeneration through the selective replacement of metallic hot section components with ceramic parts. The program focuses on design, fabrication, and testing of ceramic components, generating a materials properties data base, and applying life prediction and nondestructive evaluation (NDE). The development program is being performed by a team led by Solar Turbines Incorporated, and which includes suppliers of ceramic components, US research laboratories, and an industrial cogeneration end user. The Solar Centaur 50S engine was selected for the development program. The program goals included an increase in the turbine rotor inlet temperature (TRIT) from 1,010 C (1,850 F) to 1,121 C (2,050 F), accompanied by increases in thermal efficiency and output power. The performance improvements are attributable to the increase in TRIT and the reduction in cooling air requirements for the ceramic parts. The ceramic liners are also expected to lower the emissions of NOx and CO. Under the program uncooled ceramic blades and nozzles have been inserted for currently cooled metal components in the first stage of the gas producer turbine. The louvre-cooled metal combustor liners have been replaced with uncooled continuous-fiber reinforced ceramic composite (CFCC) liners. Modifications have been made to the engine hot section to accommodate the ceramic parts. To date, all first generation designs have been completed. Ceramic components have been fabricated, and are being tested in rigs and in the Centaur 50S engine. Field testing at an industrial co-generation site was started in May, 1997. This paper will provide an update of the development work and details of engine testing of ceramic components under the program.

Price, J.R.; Jimenez, O.; Faulder, L.; Edwards, B.; Parthasarathy, V.

1999-10-01T23:59:59.000Z

395

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect (OSTI)

This is the fourth quarterly report on a new study to develop a ceramic membrane/metal joint. The first experiments using the La-Sr-Fe-O ceramic are reported. Some of the analysis performed on the samples obtained are commented upon. A set of experiments to characterize the mechanical strength and thermal fatigue properties of the joints has been designed and begun. Finite element models of joints used to model residual stresses are described.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2000-07-01T23:59:59.000Z

396

Battery utilizing ceramic membranes  

DOE Patents [OSTI]

A thin film battery is disclosed based on the use of ceramic membrane technology. The battery includes a pair of conductive collectors on which the materials for the anode and the cathode may be spin coated. The separator is formed of a porous metal oxide ceramic membrane impregnated with electrolyte so that electrical separation is maintained while ion mobility is also maintained. The entire battery can be made less than 10 microns thick while generating a potential in the 1 volt range.

Yahnke, Mark S. (Berkeley, CA); Shlomo, Golan (Haifa, IL); Anderson, Marc A. (Madison, WI)

1994-01-01T23:59:59.000Z

397

In-Pile Experiment of a New Hafnium Aluminide Composite Material to Enable Fast Neutron Testing in the Advanced Test Reactor  

SciTech Connect (OSTI)

A new hafnium aluminide composite material is being developed as a key component in a Boosted Fast Flux Loop (BFFL) system designed to provide fast neutron flux test capability in the Advanced Test Reactor. An absorber block comprised of hafnium aluminide (Al3Hf) particles (~23% by volume) dispersed in an aluminum matrix can absorb thermal neutrons and transfer heat from the experiment to pressurized water cooling channels. However, the thermophysical properties, such as thermal conductivity, of this material and the effect of irradiation are not known. This paper describes the design of an in-pile experiment to obtain such data to enable design and optimization of the BFFL neutron filter.

Donna Post Guillen; Douglas L. Porter; James R. Parry; Heng Ban

2010-06-01T23:59:59.000Z

398

Dense, finely, grained composite materials  

DOE Patents [OSTI]

Dense, finely grained composite materials comprising one or more ceramic phase or phase and one or more metallic and/or intermetallic phase or phases are produced by combustion synthesis. Spherical ceramic grains are homogeneously dispersed within the matrix. Methods are provided, which include the step of applying mechanical pressure during or immediately after ignition, by which the microstructures in the resulting composites can be controllably selected.

Dunmead, Stephen D. (Davis, CA); Holt, Joseph B. (San Jose, CA); Kingman, Donald D. (Danville, CA); Munir, Zuhair A. (Davis, CA)

1990-01-01T23:59:59.000Z

399

Ceramic electrolyte coating and methods  

DOE Patents [OSTI]

Aqueous coating slurries useful in depositing a dense coating of a ceramic electrolyte material (e.g., yttrium-stabilized zirconia) onto a porous substrate of a ceramic electrode material (e.g., lanthanum strontium manganite or nickel/zirconia) and processes for preparing an aqueous suspension of a ceramic electrolyte material and an aqueous spray coating slurry including a ceramic electrolyte material. The invention also includes processes for depositing an aqueous spray coating slurry including a ceramic electrolyte material onto pre-sintered, partially sintered, and unsintered ceramic substrates and products made by this process.

Seabaugh, Matthew M. (Columbus, OH); Swartz, Scott L. (Columbus, OH); Dawson, William J. (Dublin, OH); McCormick, Buddy E. (Dublin, OH)

2007-08-28T23:59:59.000Z

400

Ceramic package fabrication for YMP nuclear waste disposal  

SciTech Connect (OSTI)

The purpose of this work is to develop alternate materials/design concepts to metal barriers for the Nevada Nuclear Waste Storage Investigations Project. There is some potential that site conditions may prove to be too aggressive for successful employment of the metal alloys under current consideration or that performance assessment models will predict metal container degradation rates that are inconsistent with the goal of substantially complete containment included in the NRC regulations. In the event that the anticipated lifetimes of metal containers are considered inadequate, alternate materials (i.e. ceramics or ceramic/metal composites) will be chosen due to superior corrosion resistance. This document was prepared using information taken from the open literature, conversations and correspondence with vendors, news releases and data presented at conferences to determine what form such a package might take. This discussion presents some ceramic material selection criteria, alternatives for the materials which might be used and alternatives for potential fabrication routes. This includes {open_quotes}stand alone{close_quotes} ceramic components and ceramic coatings/linings for metallic structures. A list of companies providing verbal or written information concerning the production of ceramic or ceramic lined waste containers appears at the end of this discussion.

Wilfinger, K.

1994-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "advanced ceramic composites" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Method of preparing a high solids content, low viscosity ceramic slurry  

DOE Patents [OSTI]

A method for producing a high solids content, low viscosity ceramic slurry composition comprises turbomilling a dispersion of a ceramic powder in a liquid to form a slurry having a viscosity less than 100 centipoise and a solids content equal to or greater than 48 volume percent.

Tiegs, Terry N. (Lenoir City, TN); Wittmer, Dale E. (Carbondale, IL)

1995-01-01T23:59:59.000Z

402

Method of preparing a high solids content, low viscosity ceramic slurry  

DOE Patents [OSTI]

A method for producing a high solids content, low viscosity ceramic slurry composition comprises turbomilling a dispersion of a ceramic powder in a liquid to form a slurry having a viscosity less than 100 centipoise and a solids content equal to or greater than 48 volume percent.

Tiegs, T.N.; Wittmer, D.E.

1995-10-10T23:59:59.000Z

403

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect (OSTI)

This is the third quarterly report on oxygen Transport Ceramic Membranes. In the following, the report describes the progress made by our university partners in Tasks 1 through 6, experimental apparatus that was designed and built for various tasks of this project, thermodynamic calculations, where applicable and work planned for the future. (Task 1) Design, fabricate and evaluate ceramic to metal seals based on graded ceramic powder/metal braze joints. (Task 2) Evaluate the effect of defect configuration on ceramic membrane conductivity and long term chemical and structural stability. (Task 3) Determine materials mechanical properties under conditions of high temperatures and reactive atmospheres. (Task 4) Evaluate phase stability and thermal expansion of candidate perovskite membranes and develop techniques to support these materials on porous metal structures. (Task 5) Assess the microstructure of membrane materials to evaluate the effects of vacancy-impurity association, defect clusters, and vacancy-dopant association on the membrane performance and stability. (Task 6) Measure kinetics of oxygen uptake and transport in ceramic membrane materials under commercially relevant conditions using isotope labeling techniques.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2000-10-01T23:59:59.000Z

404

Ceramic impregnated superabrasives  

DOE Patents [OSTI]

A superabrasive fracture resistant compact is formed by depositing successive layers of ceramic throughout the network of open pores in a thermally stable self-bonded polycrystalline diamond or cubic boron nitride preform. The void volume in the preform is from approximately 2 to 10 percent of the volume of the preform, and the average pore size is below approximately 3000 nanometers. The preform is evacuated and infiltrated under at least about 1500 pounds per square inch pressure with a liquid pre-ceramic polymerizable precursor. The precursor is infiltrated into the preform at or below the boiling point of the precursor. The precursor is polymerized into a solid phase material. The excess is removed from the outside of the preform, and the polymer is pyrolized to form a ceramic. The process is repeated at least once more so as to achieve upwards of 90 percent filling of the original void volume. When the remaining void volume drops below about 1 percent the physical properties of the compact, such as fracture resistance, improve substantially. Multiple infiltration cycles result in the deposition of sufficient ceramic to reduce the void volume to below 0.5 percent. The fracture resistance of the compacts in which the pores are lined with formed in situ ceramic is generally at least one and one-half times that of the starting preforms.

Radtke, Robert P.; Sherman, Andrew

2009-02-10T23:59:59.000Z

405

Ceramic combustor mounting  

DOE Patents [OSTI]

A combustor for a gas turbine engine includes a metal engine block including a wall portion defining a housing for a combustor having ceramic liner components. A ceramic outlet duct is supported by a compliant seal on the metal block and a reaction chamber liner is stacked thereon and partly closed at one end by a ceramic bypass swirl plate which is spring loaded by a plurality of circumferentially spaced, spring loaded guide rods and wherein each of the guide rods has one end thereof directed exteriorly of a metal cover plate on the engine block to react against externally located biasing springs cooled by ambient air and wherein the rod spring support arrangement maintains the stacked ceramic components together so that a normal force is maintained on the seal between the outlet duct and the engine block under all operating conditions. The support arrangement also is operative to accommodate a substantial difference in thermal expansion between the ceramic liner components of the combustor and the metal material of the engine block.

Hoffman, Melvin G. (Speedway, IN); Janneck, Frank W. (Danville, IN)

1982-01-01T23:59:59.000Z

406

Multilayer ultra-high-temperature ceramic coatings  

DOE Patents [OSTI]

A coated carbon-carbon composite material with multiple ceramic layers to provide oxidation protection from ultra-high-temperatures, where if the carbon-carbon composite material is uninhibited with B.sub.4C particles, then the first layer on the composite material is selected from ZrB.sub.2 and HfB.sub.2, onto which is coated a layer of SiC coated and if the carbon-carbon composite material is inhibited with B.sub.4C particles, then protection can be achieved with a layer of SiC and a layer of either ZrB.sub.2 and HfB.sub.2 in any order.

Loehman, Ronald E. (Albuquerque, NM); Corral, Erica L. (Tucson, AZ)

2012-03-20T23:59:59.000Z

407

Comptes Rendus des JNC 17 -Poitiers 2011 Elaboration et caractrisation mcanique de composites matrice cramique  

E-Print Network [OSTI]

ceramic matrix composites R. Etchart-Salas, S. Jacques, A. Coradi, E. Martin Laboratoire des Composites Keywords : ceramic matrix composite, mechanical testing, acoustic emission, damage, modeling 1 IntroductionComptes Rendus des JNC 17 - Poitiers 2011 1 Elaboration et caractérisation mécanique de composites

Paris-Sud XI, Université de

408

CERAMIC MEMBRANE ENABLING TECHNOLOGY FOR IMPROVED IGCC EFFICIENCY  

SciTech Connect (OSTI)

The objective of this program is to conduct a technology development program to advance the state-of-the-art in ceramic Oxygen Transport Membranes (OTM) to the level required to produce step change improvements in process economics, efficiency, and environmental benefits for commercial IGCC systems and other applications. The IGCC program is focused on addressing key issues in materials, processing, manufacturing, engineering and system development that will make the OTM a commercial reality. The objective of the OTM materials development task is to identify a suitable material that can be formed into a thin film to produce the target oxygen flux. This requires that the material have an adequate permeation rate, and thermo-mechanical and thermo-chemical properties such that the material is able to be supported on the desired substrate and sufficient mechanical strength to survive the stresses involved in operation. The objective of the composite OTM development task is to develop the architecture and fabrication techniques necessary to construct stable, high performance, thin film OTMs supported on suitable porous, load bearing substrates. The objective of the process development task of this program to demonstrate the program objectives on a single OTM tube under test conditions simulating those of the optimum process cycle for the power plant. Good progress has been made towards achieving the DOE-IGCC program objectives. Two promising candidates for OTM materials have been identified and extensive characterization will continue. New compositions are being produced and tested which will determine if the material can be further improved in terms of flux, thermo-mechanical and thermo-chemical properties. Process protocols for the composite OTM development of high quality films on porous supports continues to be optimized. Dense and uniform PSO1 films were successfully applied on porous disc and tubular substrates with good bonding between the films and substrates, and no damage to the substrates or films.

Ravi Prasad

2000-04-01T23:59:59.000Z

409

Battery utilizing ceramic membranes  

DOE Patents [OSTI]

A thin film battery is disclosed based on the use of ceramic membrane technology. The battery includes a pair of conductive collectors on which the materials for the anode and the cathode may be spin coated. The separator is formed of a porous metal oxide ceramic membrane impregnated with electrolyte so that electrical separation is maintained while ion mobility is also maintained. The entire battery can be made less than 10 microns thick while generating a potential in the 1 volt range. 2 figs.

Yahnke, M.S.; Shlomo, G.; Anderson, M.A.

1994-08-30T23:59:59.000Z

410

Supported microporous ceramic membranes  

DOE Patents [OSTI]

A method for permformation of microporous ceramic membranes onto a porous support includes placing a colloidal suspension of metal or metal oxide particles on one side of the porous support and exposing the other side of the porous support to a drying stream of gas or a reactive gas stream so that the particles are deposited on the drying side of the support as a gel. The gel so deposited can be sintered to form a supported ceramic membrane useful for ultrafiltration, reverse osmosis, or molecular sieving having mean pore sizes less than 100 Angstroms.

Webster, Elizabeth (Madison, WI); Anderson, Marc (Madison, WI)

1993-01-01T23:59:59.000Z

411

Supported microporous ceramic membranes  

DOE Patents [OSTI]

A method for the formation of microporous ceramic membranes onto a porous support includes placing a colloidal suspension of metal or metal oxide particles on one side of the porous support and exposing the other side of the porous support to a drying stream of gas or a reactive gas stream so that the particles are deposited on the drying side of the support as a gel. The gel so deposited can be sintered to form a supported ceramic membrane useful for ultrafiltration, reverse osmosis, or molecular sieving having mean pore sizes less than 100 Angstroms. 4 figures.

Webster, E.; Anderson, M.

1993-12-14T23:59:59.000Z

412

Composite materials for fusion applications  

SciTech Connect (OSTI)

Ceramic matrix composites, CMCs, are being considered for advanced first-wall and blanket structural applications because of their high-temperature properties, low neutron activation, low density and low coefficient of expansion coupled with good thermal conductivity and corrosion behavior. This paper presents a review and analysis of the hermetic, thermal conductivity, corrosion, crack growth and radiation damage properties of CMCs. It was concluded that the leak rates of a gaseous coolant into the plasma chamber or tritium out of the blanket could exceed design criteria if matrix microcracking causes existing porosity to become interconnected. Thermal conductivities of unirradiated SiC/SiC and C/SiC materials are about 1/2 to 2/3 that of Type 316 SS whereas the thermal conductivity for C/C composites is seven times larger. The thermal stress figure-of-merit value for CMCs exceeds that of Type 316 SS for a single thermal cycle. SiC/SiC composites are very resistant to corrosion and are expected to be compatible with He or Li coolants if the O{sub 2} concentrations are maintained at the appropriate levels. CMCs exhibit subcritical crack growth at elevated temperatures and the crack velocity is a function of the corrosion conditions. The radiation stability of CMCs will depend on the stability of the fiber, microcracking of the matrix, and the effects of gaseous transmutation products on properties. 23 refs., 14 figs., 1 tab.

Jones, R.H.; Henager, C.H. Jr.; Hollenberg, G.W.

1991-10-01T23:59:59.000Z

413

Metal to ceramic sealed joint  

DOE Patents [OSTI]

A metal to ceramic sealed joint which can withstand wide variations in temperature and maintain a good seal is provided for use in a device adapted to withstand thermal cycling from about 20 to about 1000 degrees C. The sealed joint includes a metal member, a ceramic member having an end portion, and an active metal braze forming a joint to seal the metal member to the ceramic member. The joint is positioned remote from the end portion of the ceramic member to avoid stresses at the ends or edges of the ceramic member. The sealed joint is particularly suited for use to form sealed metal to ceramic joints in a thermoelectric generator such as a sodium heat engine where a solid ceramic electrolyte is joined to metal parts in the system.

Lasecki, John V. (Livonia, MI); Novak, Robert F. (Farmington Hills, MI); McBride, James R. (Ypsilanti, MI)

1991-01-01T23:59:59.000Z

414

Metal to ceramic sealed joint  

DOE Patents [OSTI]

A metal to ceramic sealed joint which can withstand wide variations in temperature and maintain a good seal is provided for use in a device adapted to withstand thermal cycling from about 20 to about 1000 degrees C. The sealed joint includes a metal member, a ceramic member having an end portion, and an active metal braze forming a joint to seal the metal member to the ceramic member. The joint is positioned remote from the end portion of the ceramic member to avoid stresses at the ends or edges of the ceramic member. The sealed joint is particularly suited for use to form sealed metal to ceramic joints in a thermoelectric generator such as a sodium heat engine where a solid ceramic electrolyte is joined to metal parts in the system. 11 figures.

Lasecki, J.V.; Novak, R.F.; McBride, J.R.

1991-08-27T23:59:59.000Z

415

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect (OSTI)

The mechanical properties of model systems were analyzed. A reasonably accurate finite element model was implemented and a rational metric to predict the strength of ceramic/metal concentrical joints was developed. The mode of failure of the ceramic/metal joints was determined and the importance of the mechanical properties of the braze material was assessed. Thermal cycling experiments were performed on the model systems and the results were discussed. Additionally, experiments using the concept of placing diffusion barriers on the ceramic surface to limit the extent of the reaction with the braze were performed. It was also observed that the nature and morphology of the reaction zone depends greatly on the nature of the perovskite structure being used. From the experiments, it is observed that the presence of Cr in the Fe-occupied sites decreases the tendency of Fe to segregate and to precipitate out of the lattice. In these new experiments, Ni was observed to play a major role in the decomposition of the ceramic substrate.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2001-05-01T23:59:59.000Z

416

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect (OSTI)

The mechanical properties of model systems were analyzed. A reasonably accurate finite element model was implemented and a rational metric to predict the strength of ceramic/metal concentrical joints was developed. The mode of failure of the ceramic/metal joints was determined and the importance of the mechanical properties of the braze material was assessed. Thermal cycling experiments were performed on the model systems and the results were discussed. Additionally, experiments using the concept of placing diffusion barriers on the ceramic surface to limit the extent of the reaction with the braze were performed. It was also observed that the nature and morphology of the reaction zone depends greatly on the nature of the perovskite structure being used. From the experiments, it is observed that the presence of Cr in the Fe-occupied sites decreases the tendency of Fe to segregate and to precipitate out of the lattice. In these new experiments, Ni was observed to play a major role in the decomposition of the ceramic substrate.

Dr. Sukumar Bandopadhyay; Dr. Nagendfra Nagabhushana

2001-07-01T23:59:59.000Z

417

Microwave processing of ceramics  

SciTech Connect (OSTI)

Recent work in the areas of microwave processing and joining of ceramics is briefly reviewed. Advantages and disadvantages of microwave processing as well as some of the current issues in the field are discussed. Current state and potential for future commercialization of this technology is also addressed.

Katz, J.D.

1993-04-01T23:59:59.000Z

418

Microwave processing of ceramics  

SciTech Connect (OSTI)

Recent work in the areas of microwave processing and joining of ceramics is briefly reviewed. Advantages and disadvantages of microwave processing as well as some of the current issues in the field are discussed. Current state and potential for future commercialization of this technology is also addressed.

Katz, J.D.

1993-01-01T23:59:59.000Z

419

elementsair ceramic plate  

E-Print Network [OSTI]

many current day applications. Anything that creates waste heat (e.g. engines, computers, electronicsearth elementsair L ceramic plate Thermoelectric Module Construction for Low Temperature Gradient Power Generation Y. Meydbray, R. Singh, Ali Shakouri University of California at Santa Cruz, Electrical

420

Coated ceramic breeder materials  

DOE Patents [OSTI]

A breeder material for use in a breeder blanket of a nuclear reactor is disclosed. The breeder material comprises a core material of lithium containing ceramic particles which has been coated with a neutron multiplier such as Be or BeO, which coating has a higher thermal conductivity than the core material.

Tam, Shiu-Wing (Downers Grove, IL); Johnson, Carl E. (Elk Grove, IL)

1987-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "advanced ceramic composites" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Microporous alumina ceramic membranes  

DOE Patents [OSTI]

Several methods are disclosed for the preparation microporous alumina ceramic membranes. For the first time, porous alumina membranes are made which have mean pore sizes less than 100 Angstroms and substantially no pores larger than that size. The methods are based on improved sol-gel techniques.

Anderson, M.A.; Guangyao Sheng.

1993-05-04T23:59:59.000Z

422

CERAMIC MEMBRANE ENABLING TECHNOLOGY FOR IMPROVED IGCC EFFICIENCY  

SciTech Connect (OSTI)

The objective of this program is to conduct a technology development program to advance the state-of-the-art in ceramic Oxygen Transport Membranes (OTM) to the level required to produce step change improvements in process economics, efficiency, and environmental benefits for commercial IGCC systems and other applications. The IGCC program is focused on addressing key issues in materials, processing, manufacturing, engineering and system development that will make the OTM a commercial reality. The objective of the OTM materials development task is to identify a suitable material that can be formed into a thin film to produce the target oxygen flux. This requires that the material have an adequate permeation rate, and thermo-mechanical and thermo-chemical properties such that the material is able to be supported on the desired substrate and sufficient mechanical strength to survive the stresses involved in operation. The objective of the composite OTM development task is to develop the architecture and fabrication techniques necessary to construct stable, high performance, thin film OTMs supported on suitable porous, load bearing substrates. The objective of the process development task of this program to demonstrate the program objectives on a single OTM tube under test conditions simulating those of the optimum process cycle for the power plant.

Ravi Prasad

2000-04-01T23:59:59.000Z

423

Method of making molten carbonate fuel cell ceramic matrix tape  

DOE Patents [OSTI]

A method of making a thin, flexible, pliable matrix material for a molten carbonate fuel cell is described. The method comprises admixing particles inert in the molten carbonate environment with an organic polymer binder and ceramic particle. The composition is applied to a mold surface and dried, and the formed compliant matrix material removed.

Maricle, Donald L. (226 Forest La., Glastonbury, CT 06033); Putnam, Gary C. (47 Walker St., Manchester, CT 06040); Stewart, Jr., Robert C. (1230 Copper Hill Rd., West Suffield, CT 06093)

1984-10-23T23:59:59.000Z

424

Advanced Industrial Materials (AIM) Program: Annual progress report FY 1995  

SciTech Connect (OSTI)

In many ways, the Advanced Industrial Materials (AIM) Program underwent a major transformation in Fiscal Year 1995 and these changes have continued to the present. When the Program was established in 1990 as the Advanced Industrial Concepts (AIC) Materials Program, the mission was to conduct applied research and development to bring materials and processing technologies from the knowledge derived from basic research to the maturity required for the end use sectors for commercialization. In 1995, the Office of Industrial Technologies (OIT) made radical changes in structure and procedures. All technology development was directed toward the seven ``Vision Industries`` that use about 80% of industrial energy and generated about 90% of industrial wastes. The mission of AIM has, therefore, changed to ``Support development and commercialization of new or improved materials to improve productivity, product quality, and energy efficiency in the major process industries.`` Though AIM remains essentially a National Laboratory Program, it is essential that each project have industrial partners, including suppliers to, and customers of, the seven industries. Now, well into FY 1996, the transition is nearly complete and the AIM Program remains reasonably healthy and productive, thanks to the superb investigators and Laboratory Program Managers. This Annual Report for FY 1995 contains the technical details of some very remarkable work by the best materials scientists and engineers in the world. Areas covered here are: advanced metals and composites; advanced ceramics and composites; polymers and biobased materials; and new materials and processes.

NONE

1996-04-01T23:59:59.000Z

425

Oxygen ion-conducting dense ceramic  

DOE Patents [OSTI]

Preparation, structure, and properties of mixed metal oxide compositions containing at least strontium, cobalt, iron and oxygen are described. The crystalline mixed metal oxide compositions of this invention have, for example, structure represented by Sr.sub..alpha. (Fe.sub.1-x Co.sub.x).sub..alpha.+.beta. O.sub..delta. where x is a number in a range from 0.01 to about 1, .alpha. is a number in a range from about 1 to about 4, .beta. is a number in a range upward from 0 to about 20, and .delta. is a number which renders the compound charge neutral, and wherein the composition has a non-perovskite structure. Use of the mixed metal oxides in dense ceramic membranes which exhibit oxygen ionic conductivity and selective oxygen separation, are described as well as their use in separation of oxygen from an oxygen-containing gaseous mixture.

Balachandran, Uthamalingam (Hinsdale, IL); Kleefisch, Mark S. (Naperville, IL); Kobylinski, Thaddeus P. (Lisle, IL); Morissette, Sherry L. (Las Cruces, NM); Pei, Shiyou (Naperville, IL)

1997-01-01T23:59:59.000Z

426

Oxygen ion-conducting dense ceramic  

DOE Patents [OSTI]

Preparation, structure, and properties of mixed metal oxide compositions containing at least strontium, cobalt, iron and oxygen are described. The crystalline mixed metal oxide compositions of this invention have, for example, structure represented by Sr.sub..alpha. (Fe.sub.1-x Co.sub.x).sub..alpha.+.beta. O.sub..delta. where x is a number in a range from 0.01 to about 1, .alpha. is a number in a range from about 1 to about 4, .beta. is a number in a range upward from 0 to about 20, and .delta. is a number which renders the compound charge neutral, and wherein the composition has a non-perovskite structure. Use of the mixed metal oxides in dense ceramic membranes which exhibit oxygen ionic conductivity and selective oxygen separation, are described as well as their use in separation of oxygen from an oxygen-containing gaseous mixture.

Balachandran, Uthamalingam (Hinsdale, IL); Kleefisch, Mark S. (Naperville, IL); Kobylinski, Thaddeus P. (Lisle, IL); Morissette, Sherry L. (Las Cruces, NM); Pei, Shiyou (Naperville, IL)

1996-01-01T23:59:59.000Z

427

Ceramic Technology Project, semiannual progress report for October 1993 through March 1994  

SciTech Connect (OSTI)

The Ceramic Technology Project was originally developed by the Department of Energy`s Office of Transportation Systems (OTS) in Conservation and Renewable Energy. Significant accomplishments in fabricating ceramic components for the Department of Energy (DOE), National Aeronautics and Space Administration (NASA), and Department of Defense (DoD) advanced heat engine programs have provided evidence that the operation of ceramic parts in high-temperature engine environments is feasible. An assessment of needs was completed, and a five-year project plan was developed with extensive input from private industry. In July 1990, the original plan was updated through the estimated completion of development in 1993. The original objective of the project was to develop the industrial technology base required for reliable ceramics for application in advanced automotive heat engines. During the course of the Ceramic Technology Project, remarkable progress has been made in the development of reliable structural ceramics. The direction of the Ceramic Technology Project is now shifting toward reducing the cost of ceramics to facilitate commercial introduction of ceramic components for near-term engine applications. In response to extensive input from industry, the plan is to extend the engine types which were previously supported (advanced gas turbine and low-heat-rejection diesel engines) to include near-term (5-10 years) applications in conventional automobile and diesel truck engines. To facilitate the rapid transfer of this technology to U.S. industry, the major portion of the work is being done in the ceramic industry, with technological support from government laboratories, other industrial laboratories, and universities. A systematic approach to reducing the cost of components is envisioned.

Johnson, D.R.

1994-09-01T23:59:59.000Z

428

Application of organosilicon pre-sic polymer technology to optimize rapid prototyping of ceramic components  

SciTech Connect (OSTI)

Developments of applications of advanced ceramics e.g., SiC, Si{sub 3}N{sub 4}, CMCs need to be on a faster track than what the current processing technologies can afford. Rapid reduction in time to market of new and complex products can be achieved by using Rapid Prototyping and Manufacturing Technologies (RP&M) e.g., 3D-printing, selective laser sintering, stereolithography etc. These technologies will help advanced ceramics meet the performance challenges at an affordable price with reliable manufacturing technologies. The key variables of the RP&M technologies for ceramics are the nature of the polymer carrier and/or the binder, and the powder. Selection and/or the production of a proper class of polymer carrier/binder, understanding their impact on the processing of ceramics such as polymer-powder interaction, speed of hardening the green body in a controlled manner, ability to retain shape during forming and consolidation, delivering desirable properties at the end, are crucial to develop the low cost, high quality ceramic products. Organosilicon pre-SiC polymer technology route to advanced ceramics is currently being commercialized by Dow Corning. Methods to use this class of polymer as a processing aid in developing potentially better RP&M technologies to make better ceramics have been proposed in this work.

Saha, C.K.; Zank, G. [Dow Corning Corporation, Midland, MI (United States); Ghosh, A. [Philips Display Components Co., Ann Arbor, MI (United States)

1995-12-01T23:59:59.000Z

429

Oxygen Transport Ceramic Membranes  

SciTech Connect (OSTI)

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. Thermogravimetric analysis (TGA) was carried out on La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} to investigate oxygen deficiency ({delta}) of the sample. The TGA was performed in a controlled atmosphere using oxygen, argon, carbon monoxide and carbon dioxide with adjustable gas flow rates. In this experiment, the weight loss and gain of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} was directly measured by TGA. The weight change of the sample was evaluated at between 600 and 1250 C in air or 1000 C as a function of oxygen partial pressure. The oxygen deficiencies calculated from TGA data as a function of oxygen activity and temperature will be estimated and compared with that from neutron diffraction measurement in air. The LSFT and LSFT/CGO membranes were fabricated from the powder obtained from Praxair Specialty Ceramics. The sintered membranes were subjected to microstructure analysis and hardness analysis. The LSFT membrane is composed of fine grains with two kinds of grain morphology. The grain size distribution was characterized using image analysis. In LSFT/CGO membrane a lot of grain pullout was observed from the less dense, porous phase. The hardness of the LSFT and dual phase membranes were studied at various loads. The hardness values obtained from the cross section of the membranes were also compared to that of the values obtained from the surface. An electrochemical cell has been designed and built for measurements of the Seebeck coefficient as a function of temperature and pressure. Measurements on La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} as a function of temperature an oxygen partial pressure are reported. Further analysis of the dilatometry data obtained previously is presented. A series of isotope transients under air separation mode (small gradient) were completed on the membrane of LSCrF-2828 at 900 C. Low pO{sub 2} atmospheres based on with CO-CO{sub 2} mixtures have also been admitted to the delivery side of the LSCrF-2828 membrane to produce the gradients which exist under syngas generation conditions. The CO-CO{sub 2} mixtures have normal isotopic {sup 18}O abundances. The evolution of {sup 18}O on the delivery side in these experiments after an {sup 18}O pulse on the air side reveals a wealth of information about the oxygen transport processes.

S. Bandopadhyay; N. Nagabhushana; T. Nithyanantham; X.-D Zhou; Y-W. Sin; H.U. Anderson; Alan Jacobson; C.A. Mims

2005-02-01T23:59:59.000Z

430

Crystalline Ceramic Waste Forms: Comparison Of Reference Process For Ceramic Waste Form Fabrication  

SciTech Connect (OSTI)

The research conducted in this work package is aimed at taking advantage of the long term thermodynamic stability of crystalline ceramics to create more durable waste forms (as compared to high level waste glass) in order to reduce the reliance on engineered and natural barrier systems. Durable ceramic waste forms that incorporate a wide range of radionuclides have the potential to broaden the available disposal options and to lower the storage and disposal costs associated with advanced fuel cycles. Assemblages of several titanate phases have been successfully demonstrated to incorporate radioactive waste elements, and the multiphase nature of these materials allows them to accommodate variation in the waste composition. Recent work has shown that they can be produced from a melting and crystallization process. The objective of this report is to explore the phase formation and microstructural differences between lab scale melt processing in varying gas environments with alternative densification processes such as Hot Pressing (HP) and Spark Plasma Sintering (SPS). The waste stream used as the basis for the development and testing is a simulant derived from a combination of the projected Cs/Sr separated stream, the Trivalent Actinide - Lanthanide Separation by Phosphorous reagent Extraction from Aqueous Komplexes (TALSPEAK) waste stream consisting of lanthanide fission products, the transition metal fission product waste stream resulting from the transuranic extraction (TRUEX) process, and a high molybdenum concentration with relatively low noble metal concentrations. Melt processing as well as solid state sintering routes SPS and HP demonstrated the formation of the targeted phases; however differences in microstructure and elemental partitioning were observed. In SPS and HP samples, hollandite, pervoskite/pyrochlore, zirconolite, metallic alloy and TiO{sub 2} and Al{sub 2}O{sub 3} were observed distributed in a network of fine grains with small residual pores. The titanate phases that incorporate M{sup +3} rare earth elements were observed to be distinct phases (ex. Nd{sub 2}Ti{sub 2}O{sub 7}) with less degree of substitution as compared to the more homogeneous melt processed samples where a high degree of substitution and variation of composition within grains was observed. Liquid phase sintering was enhanced in reducing gas environments and resulted in large (10-200 microns) irregular shaped grains along with large voids associated with the melt process; SPS and HP samples exhibited finer grain size with smaller voids. Metallic alloys were observed in the bulk of the sample for SPS and HP samples, but were found at the bottom of the crucible in melt processed trials. These results indicate that for a first melter trial, the targeted phases can be formed in air by utilizing Ti/TiO{sub 2} additives which aid phase formation and improve the electrical conductivity. Ultimately, a melter run in reducing gas environments would be beneficial to study differences in phase formation and elemental partitioning.

Brinkman, K. S. [Savannah River National Laboratory; Marra, J. C. [Savannah River National Laboratory; Amoroso, J. [Savannah River National Laboratory; Tang, M. [Los Alamos National Laboratory

2013-08-22T23:59:59.000Z

431

Advanced hot-gas filter development. Topical report, September 30, 1994--May 31, 1996  

SciTech Connect (OSTI)

The application of high-performance, high-temperature particulate control devices is considered to be beneficial to advanced fossil fuel processing technology, to selected high-temperature industrial processes, and to waste incineration concepts. Ceramic rigid filters represent the most attractive technology for these applications due to their capability to withstand high-temperature corrosive environments. However, current generation monolithic filters have demonstrated poor resistance to crack propagation and can experience catastrophic failure during use. To address this problem, ceramic fiber-reinforced ceramic matrix composite (CMC) filter materials are needed for reliable damage tolerant candle filters. This program is focused on the development of an oxide-fiber reinforced oxide material composite filter material that is cost competitive with prototype next generation filters. This goal would be achieved through the development of a low cost sol-gel fabrication process and a three-dimensional fiber architecture optimized for high volume filter manufacturing. The 3D continuous fiber reinforcement provides a damage tolerant structure which is not subject to delamination-type failures. This report documents the Phase 1, Filter Material Development and Evaluation, results. Section 2 provides a program summary. Technical results, including experimental procedures, are presented and discussed in Section 3. Section 4 and 5 provide the Phase 1 conclusions and recommendations, respectively. The remaining sections cover acknowledgements and references.

Lane, J.E.; LeCostaouec, J.F.; Painter, C.J.; Sue, W.A.; Radford, K.C.

1996-12-31T23:59:59.000Z

432

Ceramic hot-gas filter  

DOE Patents [OSTI]

A ceramic hot-gas candle filter having a porous support of filament-wound oxide ceramic yarn at least partially surrounded by a porous refractory oxide ceramic matrix, and a membrane layer on at least one surface thereof. The membrane layer may be on the outer surface, the inner surface, or both the outer and inner surface of the porous support. The membrane layer may be formed of an ordered arrangement of circularly wound, continuous filament oxide ceramic yarn, a ceramic filler material which is less permeable than the filament-wound support structure, or some combination of continuous filament and filler material. A particularly effective membrane layer features circularly wound filament with gaps intentionally placed between adjacent windings, and a filler material of ceramic particulates uniformly distributed throughout the gap region. The filter can withstand thermal cycling during backpulse cleaning and is resistant to chemical degradation at high temperatures.

Connolly, Elizabeth Sokolinski (Wilmington, DE); Forsythe, George Daniel (Landenberg, PA); Domanski, Daniel Matthew (New Castle, DE); Chambers, Jeffrey Allen (Hockessin, DE); Rajendran, Govindasamy Paramasivam (Boothwyn, PA)

1999-01-01T23:59:59.000Z

433

Ceramic hot-gas filter  

DOE Patents [OSTI]

A ceramic hot-gas candle filter is described having a porous support of filament-wound oxide ceramic yarn at least partially surrounded by a porous refractory oxide ceramic matrix, and a membrane layer on at least one surface thereof. The membrane layer may be on the outer surface, the inner surface, or both the outer and inner surface of the porous support. The membrane layer may be formed of an ordered arrangement of circularly wound, continuous filament oxide ceramic yarn, a ceramic filler material which is less permeable than the filament-wound support structure, or some combination of continuous filament and filler material. A particularly effective membrane layer features circularly wound filament with gaps intentionally placed between adjacent windings, and a filler material of ceramic particulates uniformly distributed throughout the gap region. The filter can withstand thermal cycling during back pulse cleaning and is resistant to chemical degradation at high temperatures.

Connolly, E.S.; Forsythe, G.D.; Domanski, D.M.; Chambers, J.A.; Rajendran, G.P.

1999-05-11T23:59:59.000Z

434

Ceramics for fusion applications  

SciTech Connect (OSTI)

Ceramics are required for a variety of uses in both near-term fusion devices and in commercial powerplants. These materials must retain adequate structural and electrical properties under conditions of neutron, particle, and ionizing irradiation; thermal and applied stresses; and physical and chemical sputtering. Ceramics such as Al/sub 2/O/sub 3/, MgAl/sub 2/O/sub 4/, BeO, Si/sub 3/N/sub 4/ and SiC are currently under study for fusion applications, and results to date show widely-varying response to the fusion environment. Materials can be identified today which will meet initial operating requirements, but improvements in physical properties are needed to achieve satisfactory lifetimes for critical applications.

Clinard, F.W. Jr.

1986-01-01T23:59:59.000Z

435

Dielectric behavior of barium modified strontium bismuth titanate ceramic  

SciTech Connect (OSTI)

Barium Modified Strontium Bismuth Titanate(SBT) ceramic with general formula Sr1?xBaxBi4Ti4O15 is prepared by solid state reaction route. The structural analysis of the ceramics was done by X-ray diffraction technique. The X-ray patterns show that all the compositions are of single phase with orthorhombic structure. The temperature dependent dielectric behavior shows that the transition temperature decreases with Ba content but the maximum dielectric constant increases. The decreases of the transition with increase in Ba{sup 2+} ion, may be due to the decrease of orthorhombicity by the incorporation of Ba{sup 2+} ion in SBT lattice.

Nayak, P., E-mail: priyambada.pce@gmail.com [Department of Physics, National Institute of Technology, Rourkela, Odisha-769008 (India); Badapanda, T. [Department of Physics, C.V. Raman College of Engineering, Bhubaneswar, Odisha-752054 (India); Anwar, S.; Panigrahi, S. [Colloids and Materials Chemistry, Institute of Minerals and Materials Technology, Bhubaneswar, Odisha-751013 (India)

2014-04-24T23:59:59.000Z

436

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect (OSTI)

Conversion of natural gas to liquid fuels and chemicals is a major goal for the Nation as it enters the 21st Century. Technically robust and economically viable processes are needed to capture the value of the vast reserves of natural gas on Alaska's North Slope, and wean the Nation from dependence on foreign petroleum sources. Technologies that are emerging to fulfill this need are all based syngas as an intermediate. Syngas (a mixture of hydrogen and carbon monoxide) is a fundamental building block from which chemicals and fuels can be derived. Lower cost syngas translates directly into more cost-competitive fuels and chemicals. The currently practiced commercial technology for making syngas is either steam methane reforming (SMR) or a two-step process involving cryogenic oxygen separation followed by natural gas partial oxidation (POX). These high-energy, capital-intensive processes do not always produce syngas at a cost that makes its derivatives competitive with current petroleum-based fuels and chemicals. This project has the following 6 main tasks: Task 1--Design, fabricate and evaluate ceramic to metal seals based on graded ceramic powder/metal braze joints. Task 2--Evaluate the effect of defect configuration on ceramic membrane conductivity and long term chemical and structural stability. Task 3--Determine materials mechanical properties under conditions of high temperatures and reactive atmospheres. Task 4--Evaluate phase stability and thermal expansion of candidate perovskite membranes and develop techniques to support these materials on porous metal structures. Task 5--Assess the microstructure of membrane materials to evaluate the effects of vacancy-impurity association, defect clusters, and vacancy-dopant association on the membrane performance and stability. Task 6--Measure kinetics of oxygen uptake and transport in ceramic membrane materials under commercially relevant conditions using isotope labeling techniques.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2001-12-01T23:59:59.000Z

437

Superplastic forging nitride ceramics  

DOE Patents [OSTI]

The invention relates to producing relatively flaw free silicon nitride ceramic shapes requiring little or no machining by superplastic forging This invention herein was made in part under Department of Energy Grant DE-AC01-84ER80167, creating certain rights in the United States Government. The invention was also made in part under New York State Science and Technology Grant SB1R 1985-10.

Panda, Prakash C. (Ithaca, NY); Seydel, Edgar R. (Ithaca, NY); Raj, Rishi (Ithaca, NY)

1988-03-22T23:59:59.000Z

438

Miniature ceramic fuel cell  

DOE Patents [OSTI]

A miniature power source assembly capable of providing portable electricity is provided. A preferred embodiment of the power source assembly employing a fuel tank, fuel pump and control, air pump, heat management system, power chamber, power conditioning and power storage. The power chamber utilizes a ceramic fuel cell to produce the electricity. Incoming hydro carbon fuel is automatically reformed within the power chamber. Electrochemical combustion of hydrogen then produces electricity.

Lessing, Paul A. (Idaho Falls, ID); Zuppero, Anthony C. (Idaho Falls, ID)

1997-06-24T23:59:59.000Z

439

Joined ceramic product  

DOE Patents [OSTI]

According to the present invention, a joined product is at least two ceramic parts, specifically bi-element carbide parts with a bond joint therebetween, wherein the bond joint has a metal silicon phase. The bi-element carbide refers to compounds of MC, M.sub.2 C, M.sub.4 C and combinations thereof, where M is a first element and C is carbon. The metal silicon phase may be a metal silicon carbide ternary phase, or a metal silicide.

Henager, Jr., Charles W [Kennewick, WA; Brimhall, John L. (West Richland, WA) [West Richland, WA

2001-08-21T23:59:59.000Z

440

Microprobes aluminosilicate ceramic membranes  

DOE Patents [OSTI]

Methods have been developed to make mixed alumina-silicate and aluminosilicate particulate microporous ceramic membranes. One method involves the making of separate alumina and silica sols which are then mixed. Another method involves the creation of a combined sol with aluminosilicate particles. The resulting combined alumina and silica membranes have high surface area, a very small pore size, and a very good temperature stability.

Anderson, Marc A. (2114 Chadbourne Ave., Madison, WI 53705); Sheng, Guangyao (45 N. Orchard St., Madison, WI 53715)

1993-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "advanced ceramic composites" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Ceramic stationary gas turbine  

SciTech Connect (OSTI)

The performance of current industrial gas turbines is limited by the temperature and strength capabilities of the metallic structural materials in the engine hot section. Because of their superior high-temperature strength and durability, ceramics can be used as structural materials for hot section components (blades, nozzles, combustor liners) in innovative designs at increased turbine firing temperatures. The benefits include the ability to increase the turbine inlet temperature (TIT) to about 1200{degrees}C ({approx}2200{degrees}F) or more with uncooled ceramics. It has been projected that fully optimized stationary gas turbines would have a {approx}20 percent gain in thermal efficiency and {approx}40 percent gain in output power in simple cycle compared to all metal-engines with air-cooled components. Annual fuel savings in cogeneration in the U.S. would be on the order of 0.2 Quad by 2010. Emissions reductions to under 10 ppmv NO{sub x} are also forecast. This paper describes the progress on a three-phase, 6-year program sponsored by the U.S. Department of Energy, Office of Industrial Technologies, to achieve significant performance improvements and emissions reductions in stationary gas turbines by replacing metallic hot section components with ceramic parts. Progress is being reported for the period September 1, 1994, through September 30, 1995.

Roode, M. van

1995-12-31T23:59:59.000Z

442

Development of Cost-Effective Low-Permeability Ceramic and Refractory Components for Aluminum Melting and Casting  

SciTech Connect (OSTI)

A recent review by the U.S. Advanced Ceramics Association, the Aluminum Association, and the U.S. Department of Energy's Office of Industrial Technologies (DOE/OIT) described the status of advanced ceramics for aluminum processing, including monolithics, composites, and coatings. The report observed that monolithic ceramics (particularly oxides) have attractive properties such as resistance to heat, corrosion, thermal shock, abrasion, and erosion [1]. However, even after the developments of the past 25 years, there are two key barriers to commercialization: reliability and cost-effectiveness. Industry research is therefore focused on eliminating these barriers. Ceramic coatings have likewise undergone significant development and a variety of processes have been demonstrated for applying coatings to substrates. Some processes, such as thermal barrier coatings for gas turbine engines, exhibit sufficient reliability and service life for routine commercial use. Worldwide, aluminum melting and molten metal handling consumes about 506,000 tons of refractory materials annually. Refractory compositions for handling molten aluminum are generally based on dense fused cast silica or mullite. The microstructural texture is extremely important because an interlocking mass of coarser grains must be bonded together by smaller grains in order to achieve adequate strength. At the same time, well-distributed microscopic pores and cracks are needed to deflect cracks and prevent spalling and thermal shock damage [2]. The focus of this project was to develop and validate new classes of cost-effective, low-permeability ceramic and refractory components for handling molten aluminum in both smelting and casting environments. The primary goal was to develop improved coatings and functionally graded materials that will possess superior combinations of properties, including resistance to thermal shock, erosion, corrosion, and wetting. When these materials are successfully deployed in aluminum smelting and casting operations, their superior performance and durability will give end users marked improvements in uptime, defect reduction, scrap/rework costs, and overall energy savings resulting from higher productivity and yield. The implementation of results of this program will result in energy savings of 30 trillion Btu/year by 2020. For this Industrial Materials for the Future (IMF) project, riser tube used in the low-pressure die (LPD) casting of aluminum was selected as the refractory component for improvement. In this LPD process, a pressurized system is used to transport aluminum metal through refractory tubes (riser tubes) into wheel molds. It is important for the tubes to remain airtight because otherwise, the pressurized system will fail. Generally, defects such as porosity in the tube or cracks generated by reaction of the tube material with molten aluminum lead to tube failure, making the tube incapable of maintaining the pressure difference required for normal casting operation. Therefore, the primary objective of the project was to develop a riser tube that is not only resistant to thermal shock, erosion, corrosion, and wetting, but is also less permeable, so as to achieve longer service life. Currently, the dense-fused silica (DFS) riser tube supplied by Pyrotek lasts for only 7 days before undergoing failure. The following approach was employed to achieve the goal: (1) Develop materials and methods for sealing surface porosity in thermal-shock-resistant ceramic refractories; (2) Develop new ceramic coatings for extreme service in molten aluminum operations, with particular emphasis on coatings based on highly stable oxide phases; (3) Develop new monolithic refractories designed for lower-permeability applications using controlled porosity gradients and particle size distributions; (4) Optimize refractory formulations to minimize wetting by molten aluminum, and characterize erosion, corrosion, and spallation rates under realistic service conditions; and (5) Scale up the processing methods to full-sized components and perform field testi

Kadolkar, Puja [ORNL; Ott, Ronald D [ORNL

2006-02-01T23:59:59.000Z

443

AMERICAN CERAMIC SOCIETY e m e r g i n g c e r a m i c s & g l a s s t e c h n o l o g y  

E-Print Network [OSTI]

industry . . . . . . . . . . . . . . 36 Travis Busbee Die-castable ceramic-reinforced metal-matrix. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Victoria Knox Percolated ceramic composites: Characterization and optimizationbulletin AMERICAN CERAMIC SOCIETY e m e r g i n g c e r a m i c s & g l a s s t e c h n o l o g y

Tullos, Desiree

444

Westinghouse advanced particle filter system  

SciTech Connect (OSTI)

Integrated Gasification Combined Cycles (IGCC), Pressurized Fluidized Bed Combustion (PFBC) and Advanced PFBC (APFB) are being developed and demonstrated for commercial power generation application. Hot gas particulate filters are key components for the successful implementation of IGCC, PFBC and APFB in power generation gas turbine cycles. The objective of this work is to develop and qualify through analysis and testing a practical hot gas ceramic barrier filter system that meets the performance and operational requirements of these advanced, solid fuel power generation cycles.

Lippert, T.E.; Bruck, G.J.; Sanjana, Z.N.; Newby, R.A.

1995-11-01T23:59:59.000Z

445

FILTER COMPONENT ASSESSMENT--CERAMIC CANDLES--  

SciTech Connect (OSTI)

Efforts at Siemens Westinghouse Power Corporation (SWPC) have been focused on development of hot gas filter systems as an enabling technology for advanced coal and biomass-based gas turbine power generation applications. SWPC has been actively involved in the development of advanced filter materials and component configuration, has participated in numerous surveillance programs characterizing the material properties and microstructure of field tested filter elements, and has undertaken extended, accelerated filter life testing programs. This report summarizes the results of SWPC's filter component assessment efforts, identifying the performance and stability of porous monolithic, fiber reinforced, and filament wound ceramic hot gas candle filters, potentially for {ge}3 years of viable pressurized fluidized-bed combustion (PFBC) service operating life.

M.A. Alvin

2004-04-23T23:59:59.000Z

446

Ternary ceramic alloys of Zr-Ce-Hf oxides  

DOE Patents [OSTI]

A ternary ceramic alloy is described which produces toughening of zirconia and zirconia composites through the stress transformation from tetragonal phase to monoclinic phase. This alloy, having the general formula Ce[sub x]Hf[sub y]Zr[sub 1[minus]x[minus]y]O[sub 2], is produced through the addition of appropriate amounts of ceria and hafnia to the zirconia. Typically, improved toughness is achieved with about 5 to about 15 mol % ceria and up to about 40 mol % hafnia. The preparation of alloys of these compositions are given together with data as to the densities, tetragonal phase content, hardness and fracture toughness. The alloys are useful in preparing zirconia bodies as well as reinforcing ceramic composites. 1 fig.

Becher, P.F.; Funkenbusch, E.F.

1990-11-20T23:59:59.000Z

447

Ternary ceramic alloys of ZR-CE-HF oxides  

DOE Patents [OSTI]

A ternary ceramic alloy which produces toughening of zirconia and zirconia composites through the stress transformation from tetragonal phase to monoclinic phase. This alloy, having the general formula Ce.sub.x Hf.sub.y Zn.sub.1-x-y O.sub.2, is produced through the addition of appropriate amounts of ceria and hafnia to the zirconia. Typically, improved toughness is achieved with about 5 to about 15 mol % ceria and up to about 40 mol %