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Note: This page contains sample records for the topic "advanced ceramic composites" from the National Library of EnergyBeta (NLEBeta).
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1

Advanced Measurements of Silicon Carbide Ceramic Matrix Composites  

SciTech Connect

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

2

16 - Advances in self-healing ceramic matrix composites  

Science Journals Connector (OSTI)

Abstract: Self-healing is the capacity of a system to repair damage by itself so that cracks are sealed. For ceramic materials, especially ceramic matrix composites (CMCs), cracks can exist after processing or are created by a mechanical or thermal load. At high temperature in a moist oxidizing environment, cracks allow oxygen diffusion inside the bulk, provoking chemical degradation. To limit oxygen progression, an oxide glassy phase is used to fill cracks. This oxide is added as a protective coating or is formed by oxidation of non-oxide compounds in a protective coating or in the bulk. In the latter, the constituent undergoing oxidation acts as a chemical fuse against oxidation. Self-healing remains efficient if the oxide is chemically and thermally stable.

F. Rebillat

2014-01-01T23:59:59.000Z

3

Continuous Fiber Ceramic Composites  

SciTech Connect

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

4

Ceramic-silicide composites  

SciTech Connect

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

5

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

6

ALS Ceramics Materials Research Advances Engine Performance  

NLE Websites -- All DOE Office Websites (Extended Search)

ALS Ceramics Materials Research ALS Ceramics Materials Research Advances Engine Performance ALS Ceramics Materials Research Advances Engine Performance Print Thursday, 27 September 2012 00:00 LBNL senior materials scientist and UC Berkeley professor Rob Ritchie has been researching the fracture behavior of a wide array of materials for the past 40 years, the last ten of them using the facilities at the ALS. From human bone to synthetic engineering materials such as shape-memory metals and composites, Ritchie has illuminated groundbreaking cracking patterns and the underlying mechanistic processes using the x-ray synchrotron micro-tomography at ALS Beamline 8.3.2. Summary Slide ritchie ceramics This 3D image of a ceramic composite specimen imaged under load at 1750C shows the detailed fracture patterns that researchers are able to view using ALS Beamline 8.3.2. The vertical white lines are the individual silicon carbide fibers in this sample about 500 microns in diameter.

7

Multifracture of ceramic composites  

SciTech Connect

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

8

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

9

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

10

ALS Ceramics Materials Research Advances Engine Performance  

NLE Websites -- All DOE Office Websites (Extended Search)

ALS Ceramics Materials Research ALS Ceramics Materials Research Advances Engine Performance ALS Ceramics Materials Research Advances Engine Performance Print Thursday, 27 September 2012 00:00 ritchie ceramics This 3D image of a ceramic composite specimen imaged under load at 1750C shows the detailed fracture patterns that researchers are able to view using ALS Beamline 8.3.2. The vertical white lines are the individual silicon carbide fibers in this sample about 500 microns in diameter. LBNL senior materials scientist and U.C. Berkeley professor Rob Ritchie has been researching the fracture behavior of a wide array of materials for the past 40 years, the last ten of them using the facilities at the ALS. From human bone to synthetic engineering materials such as shape-memory metals

11

ALS Ceramics Materials Research Advances Engine Performance  

NLE Websites -- All DOE Office Websites (Extended Search)

ALS Ceramics Materials Research ALS Ceramics Materials Research Advances Engine Performance ALS Ceramics Materials Research Advances Engine Performance Print Thursday, 27 September 2012 00:00 ritchie ceramics This 3D image of a ceramic composite specimen imaged under load at 1750C shows the detailed fracture patterns that researchers are able to view using ALS Beamline 8.3.2. The vertical white lines are the individual silicon carbide fibers in this sample about 500 microns in diameter. LBNL senior materials scientist and U.C. Berkeley professor Rob Ritchie has been researching the fracture behavior of a wide array of materials for the past 40 years, the last ten of them using the facilities at the ALS. From human bone to synthetic engineering materials such as shape-memory metals

12

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

13

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

14

Cement, Ceramics, and Composites  

Science Journals Connector (OSTI)

Cement and its applications as concrete (a composite of cement and aggregate) are known throughout the world. The most common cement used today is Portland, named after the gray rock of Portland, Eng...

O. V. Roussak; H. D. Gesser

2013-01-01T23:59:59.000Z

15

Cement, Ceramics, and Composites  

Science Journals Connector (OSTI)

Cement and its applications as concrete (a composite of cement and aggregate) is known throughout the world. The most common cement used today is Portland, named after the grey rock of Portland, Engl...

H. D. Gesser

2002-01-01T23:59:59.000Z

16

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

17

ALS Ceramics Materials Research Advances Engine Performance  

NLE Websites -- All DOE Office Websites (Extended Search)

image of a ceramic composite specimen imaged under load at 1750C shows the detailed fracture patterns that researchers are able to view using ALS Beamline 8.3.2. The vertical...

18

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

19

Composite carbon-ceramic hollow fiber membranes  

SciTech Connect

This work describes the synthesis of a new type of composite membrane by applying porous ceramic layers onto the surface of carbon membranes using the sol-gel process. The pore structure is discussed.

Linkov, V.M.; Kaiser, K.; Sanderson, R.; Lapidus, A.L. [Rossiiskaya Akademiya, Nauk (Russian Federation)

1994-12-31T23:59:59.000Z

20

The Center for Advanced Ceramics Technology CACT | Open Energy Information  

Open Energy Info (EERE)

Center for Advanced Ceramics Technology CACT Center for Advanced Ceramics Technology CACT Jump to: navigation, search Name The Center for Advanced Ceramics Technology (CACT) Place Alfred, New York Zip 14802 Product CACT is a NYSTAR-funded organization within the College of Ceramics at Alfred University that is dedicated to creating a diverse, stable, technological basis for the growth of the ceramics and glass industry statewide. References The Center for Advanced Ceramics Technology (CACT)[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. The Center for Advanced Ceramics Technology (CACT) is a company located in Alfred, New York . References ↑ "The Center for Advanced Ceramics Technology (CACT)"

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

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

22

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

23

Robocasting of Ceramics and Composites Using Fine Particle Suspensions  

SciTech Connect

Solid freeform fabrication is the near-net-shape manufacturing of components by sequentially stacking thin layers of material until complicated three dimensional shapes are produced. The operation is computer controlled and requires no molds. This exciting new field of technology provides engineers with the ability to rapidly produce prototype parts directly from CAD drawings and oftentimes little or no machining is necessary after fabrication. Techniques for freeform fabrication with several types of plastics and metals are already quite advanced and maybe reviewed in references 1 and 2. Very complicated plastic models can be fabricated by stereolithography, selective laser sintering, fused deposition modeling, or three-dimensional ink jet printing. Metals may be freeformed by the LENS{trademark} technique and porous ceramic bodies by three dimensional printing into a porous powder bed. However, methods for freeform fabrication that utilize particulate slurries to build dense ceramics and composites are not as well developed. The techniques that are being developed for the freeform fabrication of dense structural ceramics primarily revolve around the sequential layering of ceramic loaded polymers or waxes. Laminated Object Manufacturing and CAM-LEM processing use controlled stacking and laser cutting of ceramic tapes [2,3]. Similar to fused deposition modeling, ceramic loaded polymer/wax filaments are being used for the fused deposition of ceramics [2,4]. Extrusion freeform fabrication uses high pressure extrusion to deposit layers of ceramic loaded polymer/wax systems[1]. Modified stereolithographic techniques are also being developed using ceramic loaded ultraviolet curable resins [2]. Pre-sintered parts made with any of these techniques typically have 40-55 vol.% polymeric binder. In this regard, these techniques are analogous to powder injection molding of ceramics. Very long and complicated burnout heat treatments are necessary to produce a dense ceramic, free of organics. Heating rates of 0.2 degrees Celsius per minute are common. [5] Thus, while a part maybe rapidly prototype within a few hours, it takes several days to densify. In contrast, robocasting is a freeform fabrication technique developed at Sandia National Labs that utilizes particulate slurries but does not require organic binders. Since binder burnout is not an issue, a dense ceramic part maybe freeformed, dried, and sintered in less than 24 hours. In some regards, robocasting is analogous to the ceramic near-net-shape processing techniques, slip casting and gel casting [6]; however, robocasting is moldless and fabrication times can be quicker.

CESARANO III,JOSEPH

1999-10-28T23:59:59.000Z

24

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

25

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

26

Revolutionizing Clean Energy Technology with Advanced Composites...  

NLE Websites -- All DOE Office Websites (Extended Search)

Revolutionizing Clean Energy Technology with Advanced Composites Revolutionizing Clean Energy Technology with Advanced Composites Addthis...

27

Plasma etching a ceramic composite. [Evaluating microstructure  

SciTech Connect

Plasma etching is found to be a superior metallographic technique for evaluating the microstructure of a ceramic matrix composite. The ceramic composite studied is composed of silicon carbide whiskers (SiC(sub W)) in a matrix of silicon nitride (Si3N4), glass, and pores. All four constituents are important in evaluating the microstructure of the composite. Conventionally prepared samples, both as-polished or polished and etched with molten salt, do not allow all four constituents to be observed in one specimen. As-polished specimens allow examination of the glass phase and porosity, while molten salt etching reveals the Si3N4 grain size by removing the glass phase. However, the latter obscures the porosity. Neither technique allows the SiC(sub W) to be distinguished from the Si3N4. Plasma etching with CF4 + 4 percent O2 selectively attacks the Si3N4 grains, leaving SiC(sub W) and glass in relief, while not disturbing the pores. An artifact of the plasma etching reaction is the deposition of a thin layer of carbon on Si3N4, allowing Si3N4 grains to be distinguished from SiC(sub W) by back scattered electron imaging.

Hull, D.R.; Leonhardt, T.A.; Sanders, W.A.

1992-01-01T23:59:59.000Z

28

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

29

Method of making sintered ductile intermetallic-bonded ceramic composites  

DOE Patents (OSTI)

A method of making an intermetallic-bonded ceramic composite involves combining a particulate brittle intermetallic precursor with a particulate reactant metal and a particulate ceramic to form a mixture and heating the mixture in a non-oxidizing atmosphere at a sufficient temperature and for a sufficient time to react the brittle intermetallic precursor and the reactant metal to form a ductile intermetallic and sinter the mixture to form a ductile intermetallic-bonded ceramic composite. 2 figs.

Plucknett, K.; Tiegs, T.N.; Becher, P.F.

1999-05-18T23:59:59.000Z

30

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.

31

Interfacial chemistry and structure in ceramic composites  

SciTech Connect

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

32

A Perspective on New Ceramics and Ceramic Composites [and Discussion  

Science Journals Connector (OSTI)

...technological problems of some important processes are solved, progress will be delayed...and rapid progress in the productive process technology of electronic (or functional...however, with, for example, the commercialization of a ceramic turbocharger by Nissan...

1987-01-01T23:59:59.000Z

33

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

34

Continuous Fiber Ceramic Composite (CFCC) Program: Gaseous Nitridation  

SciTech Connect

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

35

Advanced ceramic materials for next-generation nuclear applications  

Science Journals Connector (OSTI)

The nuclear industry is at the eye of a 'perfect storm' with fuel oil and natural gas prices near record highs, worldwide energy demands increasing at an alarming rate, and increased concerns about greenhouse gas (GHG) emissions that have caused many to look negatively at long-term use of fossil fuels. This convergence of factors has led to a growing interest in revitalization of the nuclear power industry within the United States and across the globe. Many are surprised to learn that nuclear power provides approximately 20% of the electrical power in the US and approximately 16% of the world-wide electric power. With the above factors in mind, world-wide over 130 new reactor projects are being considered with approximately 25 new permit applications in the US. Materials have long played a very important role in the nuclear industry with applications throughout the entire fuel cycle; from fuel fabrication to waste stabilization. As the international community begins to look at advanced reactor systems and fuel cycles that minimize waste and increase proliferation resistance, materials will play an even larger role. Many of the advanced reactor concepts being evaluated operate at high-temperature requiring the use of durable, heat-resistant materials. Advanced metallic and ceramic fuels are being investigated for a variety of Generation IV reactor concepts. These include the traditional TRISO-coated particles, advanced alloy fuels for 'deep-burn' applications, as well as advanced inert-matrix fuels. In order to minimize wastes and legacy materials, a number of fuel reprocessing operations are being investigated. Advanced materials continue to provide a vital contribution in 'closing the fuel cycle' by stabilization of associated low-level and high-level wastes in highly durable cements, ceramics, and glasses. Beyond this fission energy application, fusion energy will demand advanced materials capable of withstanding the extreme environments of high-temperature plasma systems. Fusion reactors will likely depend on lithium-based ceramics to produce tritium that fuels the fusion plasma, while high-temperature alloys or ceramics will contain and control the hot plasma. All the while, alloys, ceramics, and ceramic-related processes continue to find applications in the management of wastes and byproducts produced by these processes.

John Marra

2011-01-01T23:59:59.000Z

36

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

37

Environmental aging degradation in continuous fiber ceramic composites  

SciTech Connect

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

38

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

39

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

40

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

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

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

42

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 systems) strength of ceramic composites with two-dimensional fiber architectures presents serious challenges

Zok, Frank

43

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

44

Freeforming of Ceramics and Composites from Colloidal Slurries  

SciTech Connect

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

45

Continuous fiber ceramic composites. Phase II - Final report  

SciTech Connect

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

46

Notch Sensitivity of Ceramic Composites with Rising Fracture Resistance  

E-Print Network (OSTI)

of common notched test configurations with the material's fracture resistance. Analogous treatments of notch sensitivity have been used previously for other materials that exhibit rising fracture resistance, includingNotch Sensitivity of Ceramic Composites with Rising Fracture Resistance Michael A. Mattoni

Zok, Frank

47

Mechanical Properties of Porous-Matrix Ceramic Composites**  

E-Print Network (OSTI)

requirements of high-temperature components for future gas turbine engine technologies becomes realizable). These mechanisms per- mit the development of multiple matrix cracks, which in turn produce inelastic strain during/Mechanical Properties of Porous-Matrix Ceramic Composites REVIEWS The porous matrix concept has been developed primarily

Zok, Frank

48

11 - Cold ceramics: low-temperature processing of ceramics for applications in composites  

Science Journals Connector (OSTI)

Abstract: This chapter presents methods by which some ceramic-based and heterogeneous materials with different microstructures can be prepared without firing. The first part is on heterogeneity including the size, structure, microstructure, chemical composition, physical characteristics and behavior during use. The second part gives examples from our own experience in the laboratory over the past decade: dense aluminous cements, textured materials, porous materials and composites (lime and hemp fibers, Portland cement and hemp fibers and tape casting of aluminous cement composites). Some recommendations are given in the conclusion.

A. Smith; C. Peyratout

2014-01-01T23:59:59.000Z

49

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

50

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

NLE Websites -- All DOE Office Websites (Extended Search)

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

51

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

52

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 reaction 1-3 . Composite materials are protected by coatings; however, cracks that form as a result

Adjerid, Slimane

53

"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

54

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

E-Print Network (OSTI)

Thermal and mechanical properties of EPDM/PP + thermal shock-resistant ceramic composites Witold- nizate (TPV), a higher thermal expansion is seen after addition of the ceramic filler, a result-scale ceramic powder. To overcome the difficulty of particles dispersion and adhe- sion, the filler was modified

North Texas, University of

55

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

SciTech Connect

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

56

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

SciTech Connect

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

57

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

E-Print Network (OSTI)

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. The emphasis of processing research in the ceramic-matrix composite (CMC) area has increasingly shifted from

Barber, James R.

58

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

59

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

E-Print Network (OSTI)

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

Ortiz, Michael

60

REQUEST BY HONEYWELL INTERNATIONAL, INC., CERAMIC COMPONENTS FOR AN ADVANCE WAIVER OF DOMESTIC AND  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

, CERAMIC , CERAMIC COMPONENTS FOR AN ADVANCE WAIVER OF DOMESTIC AND FOREIGN RIGHTS IN SUBJECT INVENTIONS MADE IN THE COURSE OF OR UNDER UT-BATTELLE, LLC SUBCONTRACT NO. 4000000986 UNDER PRIME CONTRACT NO. DE-AC05-00OR22725; DOE WAIVER DOCKET W(A)-00-011 [ORO-751] Honeywell International Inc, Ceramic Components (Honeywell) has made a timely request for an advance waiver to worldwide rights in Subject Inventions made in the course of or under UT-Battelle, LLC Subcontract No. 4000000986, entitled, "Hot Section Components in Advanced Microturbines" under UT-Battelle Prime Contract No. DE-AC05-00OR22725. The scope of work involves the application of silicon nitride ceramics as hot-section components in advanced microturbines. The work is sponsored by the Office of Industrial Technologies Industrial Power Program.

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

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

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

Publications Advanced Materials and Processing of Composites for High Volume Applications Carbon Fiber SMC Advanced Materials and Processing of Composites for High Volume...

62

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

63

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

64

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

65

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

66

REQUEST BY KYOCERA INDUSTRIAL CERAMICS CORPORATION FOR AN ADVANCE WAIVER OF DOMESTIC AND FOREIGN RIGHTS IN  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

KYOCERA INDUSTRIAL CERAMICS CORPORATION FOR KYOCERA INDUSTRIAL CERAMICS CORPORATION FOR AN ADVANCE WAIVER OF DOMESTIC AND FOREIGN RIGHTS IN SUBJECT INVENTIONS MADE IN THE COURSE OF OR UNDER DEPARTMENT OF ENERGY SUBCONTRACT NO. 86X-SM400C UNDER CONTRACT NO. DE-AC05-840R21400; DOE WAIVER DOCKET W(A)-94-007 [0RO-574] Kyocera Industrial Ceramics Corporation (KICC) has made a timely request for an advance waiver to worldwide rights in Subject Inventions made in the course of or under Department of Energy (DOE) Subcontract No. 86X-SM400C. The scope of the work calls for the development of improved manufacturing techniques for making ceramic components for automotive and truck use, particularly KICC's SN235 silicon nitride (Si 3 N,). The work is sponsored by the Office of Transportation Technologies. The dollar amount of the subcontract is $3,915,673 with KICC cost sharing

67

REQUEST BY ALLIEDSIGNAL, INC., CERAMIC COMPONENTS FOR AN ADVANCE WAIVER OF  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

ALLIEDSIGNAL, INC., CERAMIC ALLIEDSIGNAL, INC., CERAMIC COMPONENTS FOR AN ADVANCE WAIVER OF DOMESTIC AND FOREIGN RIGHTS IN SUBJECT INVENTIONS MADE IN THE COURSE OF OR UNDER DEPARTMENT OF ENERGY CONTRACT NO. DE-AC05- 850R21400; SUBCONTRACT NO. 85X-SH596C; DOE WAIVER DOCKET W(A)-96-011 [ORO-628] AlliedSignal, Inc., Ceramic Components (AlliedSignal) has made a timely request for an advance waiver to worldwide rights in Subject Inventions made in the course of or under Department of Energy (DOE) Contract No. DE-AC05- 850R21400, Subcontract No. 85X-SH596C. The scope of the work calls for the development of silicon nitride ceramic materials with elongated grain structures to meet requirements for heat engine applications. This is Phase II of this contract. Under Phase I a basic in situ reinforced silicon nitride material, AS800, was

68

REQUEST BY SAINT-GOBAIN/NORTON INDUSTRIAL CERAMICS CORPORATION FOR AN ADVANCE WAIVER OF DOMESTIC AND  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

SAINT-GOBAIN/NORTON INDUSTRIAL CERAMICS SAINT-GOBAIN/NORTON INDUSTRIAL CERAMICS CORPORATION FOR AN ADVANCE WAIVER OF DOMESTIC AND FOREIGN RIGHTS IN SUBJECT INVENTIONS MADE IN THE COURSE OF OR UNDER DEPARTMENT OF ENERGY SUBCONTRACT 86X-SP234C UNDER CONTRACT DE-AC05-840R21400, AND FOR CERTAIN SUBCONTRACTS AWARDED BY SAINT-GOBAIN/NORTON INDUSTRIES CERAMICS CORPORATION THE UNDER DOE WAIVER DOCKET W(A)-94-009 [0RO-576] Saint-Gobain/Norton Industrial Ceramics Corporation (SGNICC) has made a timely request for an advance waiver to worldwide rights in Subject Inventions made in the course of or under its Subcontract 86X-SP234C with Martin Marietta Energy Systems, Inc., and for certain subcontracts awarded by SGNICC thereunder. The scope of the work calls for the development of cost effective manufacturing processes for two diesel engine parts, an exhaust valve for

69

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

SciTech Connect

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

70

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

E-Print Network (OSTI)

??The manufacturing and performance of ceramic/metal matrix composite (cermet) electrical discharge machining (EDM) electrodes have been investigated. The processing techniques necessary for creating TiB2/Cu, TaC/Cu,… (more)

Kim, Eugene Ty

2012-01-01T23:59:59.000Z

71

Laser Performance of Composite Nd:YAG/Cr:YAG Ceramics for Laser Ignition  

Science Journals Connector (OSTI)

Monolithic lasers of composite Nd:YAG/Cr:YAG ceramics with different Nd concentrations and cavity lengths were tested. A passively Q-switched pulse energy of 1.7mJ with a duration of...

Tsunekane, Masaki; Taira, Takunori

72

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

73

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

74

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

75

Advanced Manufacturing: Using Composites for Clean Energy  

Energy.gov (U.S. Department of Energy (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.

76

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

77

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

78

Development of a combustor liner composed of ceramic matrix composite (CMC)  

SciTech Connect

The Research Institute of Advanced Materials Gas-Generator (AMG), which is a joint effort by the Japan Key Technology Center and 14 firms in Japan, has, since fiscal year 1992, been conducting technological studies on an innovative gas generator that will use 20% less fuel, weight 50% less, and emit 70% less NO{sub x} than the conventional gas generator through the use of advanced materials. Within this project, there is an R and D program for applying ceramic matrix composite (CMC) liners to the combustor, which is a major component of the gas generator. In the course of R and D, continuous SiC fiber-reinforced SiC composite (SiC{sup F}/SiC) was selected as the most suitable CMD for the combustor liner because of its thermal stability and formability. An evaluation of the applicability of the SiC{sup F}/SiC composite to the combustor liner on the basis of an evaluation of its mechanical properties and stress analysis of a SiC{sup F}/SiC combustor liner was carried out, and trial SiC{sup F}/SiC combustor liners, the largest of which was 500-mm in diameter, were fabricated by the filament winding and PIP (polymer impregnation and pyrolysis) method. Using a SiC{sup F}/SiC liner built to the actual dimensions, a noncooling combustion test was carried out and even when the gas temperature was raised to 1873K at outlet of the liner, no damage was observed after the test. Through their studies, the authors have confirmed the applicability of the selected SiC{sup F}/SiC composite as a combustor liner. In this paper, the authors describe the present state of the R and D of a CMC combustor liner.

Nishio, K.; Igashira, K.I.; Take, K. [Research Inst. of Advanced Material Gas-Generator, Tokyo (Japan); Suemitsu, T. [Kawasaki Heavy Industries Limited, Hyogo (Japan)

1999-01-01T23:59:59.000Z

79

REQUEST BY ALLIEDSIGNAL, INC., CERAMIC COMPONENTS FOR AN ADVANCE WAIVER OF  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Statement of Considerations Statement of Considerations REQUEST BY ALLIEDSIGNAL, INC., CERAMIC COMPONENTS FOR AN ADVANCE WAIVER OF DOMESTIC AND FOREIGN RIGHTS IN SUBJECT INVENTIONS MADE IN THE COURSE OF OR UNDER DEPARTMENT OF ENERGY CONTRACT NO. DE-AC05- 850R21400; SUBCONTRACT NO. 85X-SH596C; DOE WAIVER DOCKET W(A)-96-012 [ORO-629] AlliedSignal, Inc., Ceramic Components (AlliedSignal) has made a timely request for an advance waiver to worldwide rights in Subject Inventions made in the course of or under Department of Energy (DOE) Contract No. DE-AC05- 850R21400, Subcontract No. 85X-SH596C. The scope of the work calls for the development of silicon nitride ceramic materials with elongated grain structures to meet requirements for heat engine applications. This waiver request is for rights

80

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

SciTech Connect

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

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

Near-net shape forming of ceramic refractory composite high temperature cartridges by VPS  

SciTech Connect

Near-net-shape forming of high temperature furnace containment cartridges is being developed using the Vacuum Plasma Spray (VPS) process. The cartridges are thin walled, 0.069 mm (0.027 in.) thick, and have been produced in continuous lengths of 58.4 cm (23 in.). VPS has been used to deposit a refractory metal wall structure (i.e., tungsten) and coat the structure both inside and out with a ceramic (i.e., alumina). The ceramic-refractory-ceramic composite provides environmental protection to the refractory metal structure from both chemical attack (inside) and oxidation (outside). Microstructures have been characterized, and limited material properties will be presented.

McKechnie, T.; Krotz, P.; Liaw, Y. [Rocketdyne, Huntsville, AL (United States); Zimmerman, F.; Holmes, R. [National Aeronautics and Space Administration, Huntsville, AL (United States). Marshall Space Flight Center

1994-12-31T23:59:59.000Z

82

Building a More Competitive American Manufacturing Industry with Advanced Composites  

Office of Energy Efficiency and Renewable Energy (EERE)

Our new Manufacturing Innovation Institute for Advanced Composites will help revolutionize clean energy technology one material at a time.

83

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

SciTech Connect

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

84

Support services for Ceramic Fiber-Ceramic Matrix Composites. Annual technical progress report  

SciTech Connect

Higher working-fluid temperatures are required to boost efficiency, exposing subsystems to more corrosive environments. Issues of special concern to ceramists are corrosion and blinding of hot-gas particulate filters and catastrophic failure of high-temperature ceramic heat exchangers. Fuel and operational factors that affect the corrosion rates of structural ceramics in coal-fired combustor systems are described, with examples of the corrosion of silicon carbide-based materials. Attention is focused on hot-gas particulate filtration and heat exchangers; gasification systems are also discussed. Objective of the report is to help the experimentalist measuring these factors to better design tests.

Hurley, J.P. [North Dakota Univ., Grand Forks, ND (United States). Energy and Environmental Research Center

1995-09-20T23:59:59.000Z

85

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

E-Print Network (OSTI)

i Am Cerom Soc 741111 2802-808 (19911 journal Estimation of Interfacial Shear in Ceramic Composites stress in a unidirectional Nicalon-fiber calcium aluminosili- cate matrix composite was determined/ matrix interface in fiber-reinforced ceramics. For example, Marshall developed a straightforward

Barber, James R.

86

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

87

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

88

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

89

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

90

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

91

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

92

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

SciTech Connect

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

93

Lighter and Stronger: Improving Clean Energy Technologies Through Advanced Composites  

Office of Energy Efficiency and Renewable Energy (EERE)

New institute aims to drive down the manufacturing costs and support the widespread use of advanced fiber-reinforced polymer composites.

94

ADVANCED CERAMIC COMPOSITES FOR MOLTEN ALUMINUM CONTACT APPLICATIONS  

SciTech Connect

A new refractory material which was developed for use in molten aluminum contact applications was shown to exhibit improved corrosion and wear resistance leading to improved thermal management through reduced heat losses caused by refractory thinning and wastage. This material was developed based on an understanding of the corrosion and wear mechanisms associated with currently used aluminum contact refractories under a U.S. Department of Energy funded project to investigate multifunctional refractory materials for energy efficient handling of molten metals. This new material has been validated through an industrial trial at a commercial aluminum rod and cable mill. Material development and results of this industrial validation trial are discussed.

Hemrick, James Gordon [ORNL] [ORNL; Peters, Klaus-Markus [ORNL] [ORNL

2009-01-01T23:59:59.000Z

95

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

SciTech Connect

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

96

Mechanical and in vitro performance of apatite–wollastonite glass ceramic reinforced hydroxyapatite composite fabricated by 3D-printing  

Science Journals Connector (OSTI)

Figure 1...shows the original morphology of the raw materials and fabricated 3DP hydroxyapatite/A–W glass ceramic composite (3DP-HAAW). As-purchased hydroxyapatite powders consist of agglomerates of needle-like c...

J. Suwanprateeb; R. Sanngam; W. Suvannapruk…

2009-06-01T23:59:59.000Z

97

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

98

REQUEST BY ALLIEDSIGNAL, INC., CERAMIC COMPONENTS, FOR AN ADVANCE WAIVER OF DOMESTIC AND FOREIGN RIGHTS IN SUBJECT  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

08/98 WED 13:55 FAX 423 576 6363 ]002 08/98 WED 13:55 FAX 423 576 6363 ]002 Statement of Considerations REQUEST BY ALLIEDSIGNAL, INC., CERAMIC COMPONENTS, FOR AN ADVANCE WAIVER OF DOMESTIC AND FOREIGN RIGHTS IN SUBJECT INVENTIONS MADE IN THE COURSE OF OR UNDER DEPARTMENT OF ENERGY CONTRACT NO. DE-AC05-840R21400; SUBCONTRACT NO. 85X-SH596C; DOE WAIVER DOCKET W(A)-98-003 [ORO-735] AlliedSignal, Inc., Ceramic Components (AlliedSignal) has made a timely request for an advance waiver to worldwide rights in Subject Inventions made in the course of or under Department of Energy (DOE) Contract No. DE-AC05-840R21400, Subcontract No. 85X-SH596C. The overall scope of work calls for the development of silicon nitride ceramic materials with elongated grain structures to meet requirements for heat engine

99

Ceramic Composites, Inc. 1110 Benfield Blvd, Ste Q, Millersville, MD 21108  

NLE Websites -- All DOE Office Websites (Extended Search)

Composites, Inc. Composites, Inc. 1110 Benfield Blvd, Ste Q, Millersville, MD 21108 A subsidiary of Technology Assessment and Transfer, Inc. 410-987-3435 fax 410-987-7172 www.techassess.com AGENCY: DOE / NETL CONTRACT: DE-FG02-03ER83627 TITLE: Enhanced Performance Carbon Foam Heat Exchanger for Power Plant Cooling REPORT: Final Technical Report PERIOD: 21 July 2003 - 13 July 2007 TPOC: Barbara Carney carney@netl.doe.gov PHONE: 304-285-4671 PI: Steven Seghi steve@techassess.com PHONE: 410-987-3435 COMPANY: Ceramic Composites, Inc. 133 Defense Hwy, Ste 212 Annapolis, MD 21401 SBIR/STTR Rights Notice These SBIR/STTR data are furnished with SBIR/STTR rights under Grant No. DE-FG02- 03ER83627. For a period of 4 years after the acceptance of all items to be delivered under this

100

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

SciTech Connect

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

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

Enhanced near net-shape ceramic refractory composite high temperature cartridge by VPS metallurgical alloying techniques  

SciTech Connect

High performance cartridges are being developed by vacuum plasma spray (VPS) forming to near net-shape for use in high temperature space furnaces. A VPS metallurgical alloying technique utilizing alloying elements (rhenium, nickel, etc.) has been developed that produces robust physical properties without jeopardizing the unique chemical properties of the VPS formed tungsten structure. Thin walled cartridges, 0.069 mm (0.027 in.) thick, are produced in continuous lengths of 58.4 cm (23 in.). A refractory metal (i.e. tungsten) is VPS formed as the cartridge wall structure, with a protective ceramic (i.e., alumina) coating inside and out. The ceramic-refractory-ceramic composite provides environmental protection to the refractory metal structure from both chemical attack inside and oxidation outside. The VPS metallurgical alloying process interjected during the spraying operation greatly reduces porosity of the microstructure while enhancing the ductility of the cartridge. Thin walled cartridges have been shown to hermetically seal demonstrating no through porosity. Microstructures have been characterized and material properties will be presented.

Krotz, P.D.; Liaw, Y.; McKechnie, T.N. [Rocketdyne, Huntsville, AL (United States); Holmes, R.; Zimmerman, F. [National Aeronautics and Space Administration, Huntsville, AL (United States). Marshall Space Flight Center

1995-12-31T23:59:59.000Z

102

The Advanced Composition Explorer power subsystem  

SciTech Connect

The Johns Hopkins University Applied Physics Laboratory, under contract with NASA Goddard Space Flight Center, has designed and launched the Advanced Composition Explorer (ACE) spacecraft. ACE is a scientific observatory housing ten instruments, and is located in a halo orbit about the L1 Sun-Earth libration point. ACE is providing real-time solar wind monitoring and data on elemental and isotopic matter of solar and galactic origin. The ACE Electrical Power Subsystem (EPS) is a fault tolerant, solar powered, shunt regulated, direct energy transfer architecture based on the Midcourse Space Experiment (MSX) EPS. The differences are that MSX used oriented solar arrays with a nickel hydrogen-battery defined bus, while ACE uses fixed solar panels with a regulated bus decoupled from its nickel cadmium (NiCd) battery. Also, magnetometer booms are mounted on two of the four ACE solar panels. The required accuracy of the magnetometers impose severe requirements on the magnetic fields induced by the solar array. Other noteworthy features include a solar cell degradation experiment, in-flight battery reconditioning, a battery requalified to a high vibrational environment, and an adjustable bus voltage setpoint. The four solar panels consist of aluminum honeycomb substrates covered with 15.1% efficient silicon cells. The cells are strung using silver interconnects and are back-wired to reduce magnetic emissions below 0.1nT. Pyrotechnic actuated, spring loaded hinges deploy the panels after spacecraft separation from the Delta II launch vehicle. Solar cell experiments on two of the panels track cell performance degradation at L1, and also distinguish any hydrazine impingement degradation which may be caused by the thrusters. Each solar panel uses a digital shunt box, containing blocking diodes and MOSFETs, for short-circuit control of its 5 solar strings. A power box contains redundant analog MOSFET shunts, the 90% efficient boost regulator, and redundant battery chargers which provide closed-loop voltage and current limiting. The booster can also be configured in flight to cause a regulated 0.6A discharge to provide partial battery reconditioning. The battery uses 18 spare 12Ah NiCd cells from the retired constellation of Navy navigation satellites. The battery unintentionally received twice the intended amplitude during vibration testing, but a packaging review and cell requalification proved the battery capable of safely operating in the more rugged environment. The control box contains redundant hybrid switching converters, shunt regulation electronics, and a circuit to switch sides in response to bus under or over-voltage. The control box also contains redundant 80C85RH-based processors which digitize all EPS telemetry and decode digital commands communicated over cross-strapped serial links with the redundant spacecraft command and data handling systems.

Panneton, P.E.; Tarr, J.E.; Goliaszewski, L.T.

1998-07-01T23:59:59.000Z

103

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

SciTech Connect

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

104

Advanced pressurized water reactor for improved resource utilization, part II - composite advanced PWR concept  

SciTech Connect

This report evaluates the enhanced resource utilization in an advanced pressurized water reactor (PWR) concept using a composite of selected improvements identified in a companion study. The selected improvements were in the areas of reduced loss of neutrons to control poisons, reduced loss of neutrons in leakage from the core, and improved blanket/reflector concepts. These improvements were incorporated into a single composite advanced PWR. A preliminary assessment of resource requirements and costs and impact on safety are presented.

Turner, S.E.; Gurley, M.K.; Kirby, K.D.; Mitchell, W III

1981-09-15T23:59:59.000Z

105

Ferroelectric polymer-ceramic composite thick films for energy storage applications  

SciTech Connect

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

106

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

SciTech Connect

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

107

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

108

Composite Battery Boost | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

Water-Like Properties of Soft Nanoparticle Suspensions Water-Like Properties of Soft Nanoparticle Suspensions Real-Time Capture of Intermediates in Enzymatic Reactions A New Multilayer-Based Grating for Hard X-ray Grating Interferometry The Most Detailed Picture Yet of a Key AIDS Protein Superconductivity with Stripes Science Highlights Archives: 2013 | 2012 | 2011 | 2010 2009 | 2008 | 2007 | 2006 2005 | 2004 | 2003 | 2002 2001 | 2000 | 1998 | Subscribe to APS Science Highlights rss feed Composite Battery Boost December 2, 2013 Bookmark and Share Normalized XANES spectra of Li/Se cell during cycling. Black line is the battery voltage profile. New composite materials based on selenium (Se) sulfides that act as the positive electrode in a rechargeable lithium-ion (Li-ion) battery could boost the range of electric vehicles by up to five times, according to

109

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

110

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

111

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

112

Radiation-tolerant joining technologies for silicon carbide ceramics and composites  

SciTech Connect

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

113

Analysis of a ceramic filled bio-plastic composite sandwich structure  

SciTech Connect

Design and analysis of a ceramic-filled bio-plastic composite sandwich structure is presented. This proposed high-dielectric structure is used as a substrate for patch antennas. A meandered-strip line-fed fractal-shape patch antenna is designed and fabricated on a copper-laminated sandwich-structured substrate. Measurement results of this antenna show 44% and 20% of bandwidths with maximum gains of 3.45 dBi and 5.87 dBi for the lower and upper bands, respectively. The half-power beam widths of 104° and 78° have been observed from the measured radiation pattern at the two resonance frequencies 0.9 GHz and 2.5?GHz.

Habib Ullah, M. [Institute of Space Science (ANGKASA), Universiti Kebangsaan Malaysia, Bangi Selangor 43600 (Malaysia) [Institute of Space Science (ANGKASA), Universiti Kebangsaan Malaysia, Bangi Selangor 43600 (Malaysia); Department of Electrical, Electronic and System Engineering, Universiti Kebangsaan Malaysia, Bangi 43600 (Malaysia); Islam, M. T. [Institute of Space Science (ANGKASA), Universiti Kebangsaan Malaysia, Bangi Selangor 43600 (Malaysia)] [Institute of Space Science (ANGKASA), Universiti Kebangsaan Malaysia, Bangi Selangor 43600 (Malaysia)

2013-11-25T23:59:59.000Z

114

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

NLE Websites -- All DOE Office Websites (Extended Search)

Tests. Introduction Advanced composite materials have been recognized as a prom- ising repair... . (2000). "FRP composites for shear strengthneing of RC beams." Proc., 3rd...

115

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

NLE Websites -- All DOE Office Websites (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...

116

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

117

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 stresses in fibers and matrix in the undamaged composite interfacial shear stress interfacial shear stress validate a 1D probabilistic model of damage evolution in unidirectional SiC/SiC composites. The key point

Paris-Sud XI, Université de

118

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

119

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

SciTech Connect

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

120

Space-Age Ceramics Get Their Toughest Test  

NLE Websites -- All DOE Office Websites (Extended Search)

Space-Age Ceramics Get Their Space-Age Ceramics Get Their Toughest Test Space-Age Ceramics Get Their Toughest Test Print Wednesday, 17 April 2013 07:23 Advanced ceramic composites can withstand the ultrahigh operational temperatures projected for hypersonic jet and next-generation gas-turbine engines, but real-time analysis of the mechanical properties of these space-age materials at ultrahigh temperatures has been a challenge-until now. Researchers have developed the first testing facility that enables microtomography of ceramic composites under controlled loads at ultrahigh temperatures and in real-time. Using this facility, they have fully resolved sequences of microcrack damage as cracks grow under load at temperatures several hundred degrees higher than previously possible. The observations are key ingredients of the high-fidelity simulations used to compute failure risks under extreme operating conditions.

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

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

SciTech Connect

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

122

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

SciTech Connect

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

123

Eighteenth international conference 'Advanced technology in powder metallurgy and ceramics', 8â??12 September 2003 at Kiev, Ukraine. Section 'Nanostructured materials'  

Science Journals Connector (OSTI)

This article provides a brief introduction to the 18th international conference held by the Frantsevich Institute for Problems of Materials Science, on advanced technology in powder metallurgy and ceramics. Five papers from the conference appear in this issue of IJNT.

Valery Skorokhod; Leonid Chernyshev

2006-01-01T23:59:59.000Z

124

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

125

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

SciTech Connect

One of the major challenges involved in the use of ceramic materials is ensuring adequate strength and durability. This activity has developed methodology which can be used during the design phase to predict the structural behavior of ceramic components. The effort involved the characterization of injection molded and hot isostatic pressed (HIPed) PY-6 silicon nitride, the development of nondestructive evaluation (NDE) technology, and the development of analytical life prediction methodology. Four failure modes are addressed: fast fracture, slow crack growth, creep, and oxidation. The techniques deal with failures initiating at the surface as well as internal to the component. The life prediction methodology for fast fracture and slow crack growth have been verified using a variety of confirmatory tests. The verification tests were conducted at room and elevated temperatures up to a maximum of 1371 {degrees}C. The tests involved (1) flat circular disks subjected to bending stresses and (2) high speed rotating spin disks. Reasonable correlation was achieved for a variety of test conditions and failure mechanisms. The predictions associated with surface failures proved to be optimistic, requiring re-evaluation of the components` initial fast fracture strengths. Correlation was achieved for the spin disks which failed in fast fracture from internal flaws. Time dependent elevated temperature slow crack growth spin disk failures were also successfully predicted.

Khandelwal, P.K.; Provenzano, N.J.; Schneider, W.E. [Allison Engine Co., Indianapolis, IN (United States)

1996-02-01T23:59:59.000Z

126

The production of advanced glass ceramic HLW forms using cold crucible induction melter  

SciTech Connect

Cold Crucible Induction Melters (CCIM) will favorably change how High-Level radioactive Waste (from nuclear fuel recovery) is treated in a near future. Unlike the existing Joule-Heated Melters (JHM) currently in operation for the glass-based immobilization of High-Level Waste (HLW), CCIM offers 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. It is concluded that glass ceramic waste forms that are tailored to immobilize fission products of HLW can be can be made from the HLW processed with the CCIM. The advantageous higher temperatures reached with the CCIM and unachievable with JHM allows the lanthanides, alkali, alkaline earths, and molybdenum to dissolve into a molten glass. Upon controlled cooling they go into targeted crystalline phases to form a glass ceramic waste form with higher waste loadings than achievable with borosilicate glass waste forms. Natural cooling proves to be too fast for the formation of all targeted crystalline phases.

Rutledge, V.J.; Maio, V. [Idaho National Laboratory: P.O. Box 1625, Idaho Falls, ID, 83415-2110 (United States)

2013-07-01T23:59:59.000Z

127

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

SciTech Connect

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

128

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

SciTech Connect

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

129

Ceramic Automotive Stirling Engine Program  

SciTech Connect

The Ceramic Automotive Stirling Engine Program evaluated the application of advanced ceramic materials to an automotive Stirling engine. The objective of the program was to evaluate the technical feasibility of utilizing advanced ceramics to increase peak engine operating temperature, and to evaluate the performance benefits of such an increase. Manufacturing cost estimates were also developed for various ceramic engine components and compared with conventional metallic engine component costs.

Not Available

1986-08-01T23:59:59.000Z

130

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

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

and Processing of Composites for High Volume Applications FY 2009 Progress Report for Lightweighting Materials - 8. Polymer Composites Research and Development Carbon Fiber SMC...

131

Ceramic Processing.qrk  

NLE Websites -- All DOE Office Websites (Extended Search)

Processing Processing Manufacturing Technologies The Ceramics and Glass Department devel- ops fabrication processes for ceramic compo- nents used in weapon applications. All phases of ceramic processing, from powders to fin- ished products, are addressed; including pow- der processing, blending, granulation, com- paction, sintering, grinding, metallization, and property measurements. In addition, multilay- er processing techniques are used to fabricate layered electrical devices. Our department has extensive experience in ferroelectric (PZT) and alumina ceramics, including cermet composi- tions (alumina - molybdenum composites) developed for hermetic electrical feedthrus, and alumina ceramics with buried ruthenium oxide based resistors. Capabilities * Perform process development activities for

132

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

133

Effect of nano-ZrO2 on microstructure and thermal shock behaviour of Al2O3/SiC composite ceramics used in solar thermal power  

Science Journals Connector (OSTI)

The Al2O3-ZrO2(3Y)-SiC composite ceramics used in solar thermal power were prepared by micrometric Al2O3, nano-ZrO2 and SiC powders under the condition of pressureless sintering. The bulk density and bending stre...

Xiaohong Xu ???; Guohao Jiao; Jianfeng Wu…

2011-04-01T23:59:59.000Z

134

Space-Age Ceramics Get Their Toughest Test  

NLE Websites -- All DOE Office Websites (Extended Search)

Space-Age Ceramics Get Their Toughest Test Print Space-Age Ceramics Get Their Toughest Test Print Advanced ceramic composites can withstand the ultrahigh operational temperatures projected for hypersonic jet and next-generation gas-turbine engines, but real-time analysis of the mechanical properties of these space-age materials at ultrahigh temperatures has been a challenge-until now. Researchers have developed the first testing facility that enables microtomography of ceramic composites under controlled loads at ultrahigh temperatures and in real-time. Using this facility, they have fully resolved sequences of microcrack damage as cracks grow under load at temperatures several hundred degrees higher than previously possible. The observations are key ingredients of the high-fidelity simulations used to compute failure risks under extreme operating conditions.

135

Space-Age Ceramics Get Their Toughest Test  

NLE Websites -- All DOE Office Websites (Extended Search)

Space-Age Ceramics Get Their Toughest Test Print Space-Age Ceramics Get Their Toughest Test Print Advanced ceramic composites can withstand the ultrahigh operational temperatures projected for hypersonic jet and next-generation gas-turbine engines, but real-time analysis of the mechanical properties of these space-age materials at ultrahigh temperatures has been a challenge-until now. Researchers have developed the first testing facility that enables microtomography of ceramic composites under controlled loads at ultrahigh temperatures and in real-time. Using this facility, they have fully resolved sequences of microcrack damage as cracks grow under load at temperatures several hundred degrees higher than previously possible. The observations are key ingredients of the high-fidelity simulations used to compute failure risks under extreme operating conditions.

136

Space-Age Ceramics Get Their Toughest Test  

NLE Websites -- All DOE Office Websites (Extended Search)

Space-Age Ceramics Get Their Toughest Test Print Space-Age Ceramics Get Their Toughest Test Print Advanced ceramic composites can withstand the ultrahigh operational temperatures projected for hypersonic jet and next-generation gas-turbine engines, but real-time analysis of the mechanical properties of these space-age materials at ultrahigh temperatures has been a challenge-until now. Researchers have developed the first testing facility that enables microtomography of ceramic composites under controlled loads at ultrahigh temperatures and in real-time. Using this facility, they have fully resolved sequences of microcrack damage as cracks grow under load at temperatures several hundred degrees higher than previously possible. The observations are key ingredients of the high-fidelity simulations used to compute failure risks under extreme operating conditions.

137

Space-Age Ceramics Get Their Toughest Test  

NLE Websites -- All DOE Office Websites (Extended Search)

Space-Age Ceramics Get Their Toughest Test Print Space-Age Ceramics Get Their Toughest Test Print Advanced ceramic composites can withstand the ultrahigh operational temperatures projected for hypersonic jet and next-generation gas-turbine engines, but real-time analysis of the mechanical properties of these space-age materials at ultrahigh temperatures has been a challenge-until now. Researchers have developed the first testing facility that enables microtomography of ceramic composites under controlled loads at ultrahigh temperatures and in real-time. Using this facility, they have fully resolved sequences of microcrack damage as cracks grow under load at temperatures several hundred degrees higher than previously possible. The observations are key ingredients of the high-fidelity simulations used to compute failure risks under extreme operating conditions.

138

High-Energy Electrospark Surface Strengthening of Steels with Composite Ceramics  

Science Journals Connector (OSTI)

The surface and cross-sectional structure, composition, and microhardness of composite coatings on ShKh15 and R6M5 steels have been studied under high-energy electrospark deposition with electrode materials based...

I. A. Podchernyaeva; A. D. Panasyuk; D. V. Yurechko…

2014-03-01T23:59:59.000Z

139

AMO's New Institute for Advanced Composites Manufacturing Innovation Will Focus on Reducing Energy Use  

Energy.gov (U.S. Department of Energy (DOE))

The Institute for Advanced Composites Manufacturing Innovation announced by President Obama today is a public-private consortium of 122 leading U.S. manufacturers, universities, and non-profits that will focus on advanced composites—materials that are three times 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 Innovation Institute, headquartered in Knoxville, Tennessee and led by the University of Tennessee, will receive $70 million in federal funding provided by the U.S. Department of Energy's Advanced Manufacturing Office.

140

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

SciTech Connect

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

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

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

142

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

143

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

144

Novel, Ceramic Membrane System For Hydrogen Separation  

SciTech Connect

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

145

Microsoft Word - 49047_ANL_NDE for Ceramic Composites.doc  

NLE Websites -- All DOE Office Websites (Extended Search)

developing various special test components with well-defined features developing various special test components with well-defined features such as delaminations and density variations that can be used as test articles for detection sensitivity by the non- contact, nondestructive methods under development. Argonne is developing several non-contact, nondestructive technologies including thermal imaging using steady-state heating, one-sided air-coupled imaging ultrasonics, and acousto-ultrasonic materials response measurements using guided plate waves. In the work of this project, directed towards estimating remaining useful lifetimes of the components, Argonne is building on their previous work directed towards silicon-based composites. Elastic modulus determination from data generated with acousto- ultrasonics methods is coupled with a damage parameter model to estimate remaining useful life when the

146

2.04 - Processing of Silicon Carbide-Based Ceramics  

Science Journals Connector (OSTI)

Abstract The history of the success of the covalently bonded compound silicon carbide (SiC) started more than a century ago (1893) with the synthesis of raw SiC by Edward Goodrich Acheson. Though even today Acheson's process is still current, other synthesis methods have also been developed for the production of SiC powders, whiskers, platelets, and fibers. Due to its low chemical reactivity, it turned out to be difficult to develop methods and processes for the production of SiC-based ceramics. In the past, many approaches for processing SiC have been attempted with specific benefits and limitations in each case. Today a large spectrum of SiC-based ceramics manufactured by a wide variety of processing techniques exists. In order to get a systematic overview over the complex set of SiC-based ceramics, they can be divided into three groups. The first group includes porous ceramics with relatively coarse SiC particles bonded in a matrix of amorphous aluminum silicate. These SiC-based ceramics may be compared with the well-known traditional silicate ceramics in terms of processing technique via sintering in air and corresponding microstructure evolution. Some grinding tools, refractory bricks and foam filters belong to this silicate bonded SiC-based ceramics. The second group is sintered as well, but the focus of attention is more sharply directed toward keeping the intrinsic characteristics of SiC as a polycrystalline ceramic material. Typically they are sintered in protective atmospheres utilizing solid-state, liquid-phase or vapor-phase (evaporation-condensation) mechanisms. However, some of the desired properties can sometimes only be achieved by using pressure-assisted sintering techniques such as axial hot pressing, hot isostatic pressing or field-assisted sintering. This group of sintered SiC-based ceramics also contains some advanced modifications such as in situ toughened or nanostructured ceramics. The third group uses three reaction bonding processes for consolidation, namely liquid-solid, gas phase, and polymer-derived reaction bonding, in order to reduce the maximum consolidation temperature and to increase densification with the aim to achieve low-to-zero shrinkage. All reaction bonding approaches result in untoughened SiC ceramics like nitride bonded, chemical vapor infiltrated silicon, carbon bonded, and ex situ toughened ceramic matrix composites (i.e. carbon and SiC fiber-reinforced ceramics). Through reaction bonding, paper and even natural products like wood can be converted into SiC-based ceramics.

Jochen Kriegesmann

2014-01-01T23:59:59.000Z

147

MIT/Marine Industry Collegium Opportunity Brief: Advanced composites for offshore structures. Held in Cambridge, Massachusetts on October 30-31, 1991  

SciTech Connect

Synopses of Presentations: An Overview of Advanced Structural Composites for Offshore Structures; High-Performance Composites for Deepwater Risers; Failure and Damage Mechanisms in Composites; Environmental Degradation of Composites; Composites Manufacturing; Steel-Concrete-Steel Sandwich Composite Construction for Permanently Floating Platforms; High-Strength Cement Composites for Marine Applications; Minimum Weight Design of Foam Core Sandwich Panels; Design of Fiber Reinforced Brittle and Quasi-Brittle Matrix Composites for Marine Applications; Offshore Applications and Requirements for Use of Advanced Composites; Polymer Composites in Structures; Non-Conventional Profiles of Composites for Structural Applications; Composite in Construction Require a Structural Design System; Economic Evaluation of Composites for Offshore Use.

Moore, J.

1991-01-01T23:59:59.000Z

148

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

149

High-temperature corrosion in advanced combustion systems  

SciTech Connect

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

150

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

151

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

152

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

153

Improving the dielectric and piezoelectric properties of screen-printed Low temperature PZT/polymer composite  

E-Print Network (OSTI)

materials, ceramics, polymers and composites. Ceramic piezoelectric materials (e.g. lead zirconate titanate of piezoelectric ceramic powders and a polymer matrix. The polymer used can itself be piezoelectric [3 of ceramic loadings in the composite (e.g.

154

AMO Announces Funding Opportunity for Low-Cost, Energy Efficient Manufacturing and Recycling of Advanced Fiber-Reinforced Polymer Composites  

Energy.gov (U.S. Department of Energy (DOE))

A new Advanced Composite Manufacturing Institute, one of six National Network for Manufacturing Innovation Institutes to launch in 2014, will receive up to $70 million over five years in Energy Department funding.

155

Polymer Coating for Immobilizing Soluble Ions in a Phosphate Ceramic Product  

SciTech Connect

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

156

Corrosion performance of ceramic materials in slagging environments  

SciTech Connect

Conceptual designs of advanced combustion systems that use coal as feedstock require high-temperature furnaces and heat transfer surfaces that can operate at temperatures much higher than in current coal-fired power plants. Combination of elevated temperatures and hostile combustion environments requires advanced ceramics. Objectives of this program are to evaluate the (a) chemistry of gaseous and condensed products arising during coal combustion, (b) corrosion behavior of candidate materials in air, slag, and salt environments, and (c)residual mechanical properties of the materials after corrosion. Temperatures in the range of 1000-1400 C for ceramics and 600-1000 C for metallic alloys are emphasized. Coal/ash chemistries developed on the basis of thermodynamic/kinetic calculations, together with slags from actual combustors, are used. Materials being evaluated include monolithic Si carbides from several sources: Si nitride, Si carbide in alumina composites, Si carbide fibers in a Si carbide-matrix composite, and some advanced Ni-base alloys. This paper presents results from an ongoing program on corrosion performance of candidate ceramic materials exposed to air, salt, and slag environments and their effect on flexural strength and energy absorbed during fracture of these materials. 10 figs, 4 tabs, 8 refs.

Natesan, K.

1996-10-01T23:59:59.000Z

157

Enabling Technologies for Ceramic Hot Section Components  

SciTech Connect

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

158

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

159

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

160

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.

Note: This page contains sample records for the topic "advanced ceramic composites" from the National Library of EnergyBeta (NLEBeta).
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We encourage you to perform a real-time search of NLEBeta
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161

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

SciTech Connect

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

162

Electric-spark hardening of VT3-1 titanium alloy with tungsten-free composite ceramics  

Science Journals Connector (OSTI)

The mass transfer and wear resistance of both monolayer and multilayer coatings on VT3-1 alloy are examined. The coatings are deposited by electrospark alloying (ESA) with composite titanium and zirconium refr...

I. A. Podchernyaeva; V. M. Panashenko…

2007-09-01T23:59:59.000Z

163

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

E-Print Network (OSTI)

interfacial design of high-temperature ceramic composites for broad applications such as power generation interfacial debonding and sliding in situ during the cracking of ceramic matrix com- posites at high applications such as matrix- nanoparticle composites [6,7] and high-power electronic devices [8]. An emerging

Southern California, University of

164

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

SciTech Connect

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

165

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

SciTech Connect

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

166

Effect of temperature and particle velocity on the erosion of a silicon carbide continuous fibre reinforced calcium aluminosilicate glass–ceramic matrix composite  

Science Journals Connector (OSTI)

A unidirectional silicon carbide continuous fibre reinforced calcium aluminosilicate (CAS/SiC) glass–ceramic matrix composite has been subjected to silica sand solid particle erosion over the temperature range 20–726°C. Initial tests were conducted with a constant mass flow rate of gas of 40 l min?1. This gave a wear rate of 0.16 mg g?1 at room temperature which increased to 0.26±0.02 mg g?1 at 400°C and above. When the increase in gas velocity, and hence particle velocity, was taken into account the wear rate was predicted to decrease with increasing temperature for a constant particle velocity. A wear rate of 0.06 mg g?1 was measured at 300°C, which showed excellent agreement with the prediction of 0.07 mg g?1. As the main mechanism of material removal is via lateral cracking, this decrease in wear rate is broadly consistent with the release of residual axial tensile stresses in the matrix resulting from mismatches in the coefficients of thermal expansion of the two phases on cooling down from the processing temperature.

A.L Ham; J.A Yeomans; J.F Watts

1999-01-01T23:59:59.000Z

167

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

NLE Websites -- All DOE Office Websites (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...

168

Effects of heat treatment and formulation on the phase composition and chemical durability of the EBR-ll ceramic waste form.  

SciTech Connect

High-level radioactive waste salts generated during the electrometallurgical treatment of spent sodium-bonded nuclear fuel from the Experimental Breeder Reactor-II will be immobilized in a ceramic waste form (CWF). Tests are being conducted to evaluate the suitability of the CWF for disposal in the planned federal high-level radioactive waste repository at Yucca Mountain. In this report, the results of laboratory tests and analyses conducted to address product consistency and thermal stability issues called out in waste acceptance requirements are presented. The tests measure the impacts of (1) variations in the amounts of salt and binder glass used to make the CWF and (2) heat treatments on the phase composition and chemical durability of the waste form. A series of CWF materials was made to span the ranges of salt and glass contents that could be used during processing: between 5.0 and 15 mass% salt loaded into the zeolite (the nominal salt loading is 10.7%, and the process control range is 10.6 to 11.2 mass%), and between 20 and 30 mass% binder glass mixed with the salt-loaded zeolite (the nominal glass content is 25% and the process control range is 20 to 30 mass%). In another series of tests, samples of two CWF products made with the nominal salt and glass contents were reheated to measure the impact on the phase composition and durability: long-term heat treatments were conducted at 400 and 500 C for durations of 1 week, 4 weeks, 3 months, 6 months, and 1 year; short-term heat treatments were conducted at 600, 700, 800, and 850 C for durations of 4, 28, 52, and 100 hours. All of the CWF products that were made with different amounts of salt, zeolite, and glass and all of the heat-treated CWF samples were analyzed with powder X-ray diffraction to measure changes in phase compositions and subjected to 7-day product consistency tests to measure changes in the chemical durability. The salt loading had the greatest impact on phase composition and durability. A relatively large amount of nepheline, Na{sub 4}(AlSiO{sub 4}){sub 4}, was formed in the material made with 5.0 mass% salt loading, which was also the least durable of the materials that were tested. Nepheline was not detected in materials made with salt-loaded zeolites containing 15 or 20 mass% salt. Conversely, halite was not detected with XRD in materials made with 5.0 or 7.5 mass% salt loading, but similar amounts of halite were measured in the other CWF materials. The sodalite contents of all materials were similar. The halite content in the CWF source material used in the short-term heat-treatment study, which had the nominal salt and binder glass loadings, was determined to be about 1.3 mass% by standard addition analysis. Heat treatment had only a small effect on the phase composition: the amount of halite increased to as much as 3.7 mass%, and trace amounts of nepheline were detected in samples treated at 800 and 850 C. The CWF samples treated at high temperatures had lower amounts of halite detected in the rapid water-soluble test. The releases of B, Na, and Si in the product consistency tests (PCTs) were not sensitive to the heat-treatment conditions. The PCT responses of all salt-loaded and heat-treated CWF materials were well below that of the Environmental Assessment (EA) glass.

Ebert, W. E.; Dietz, N. L.; Janney, D. E.

2006-01-31T23:59:59.000Z

169

Assessment of Silicon Carbide Composites for Advanced Salt-Cooled Reactors  

SciTech Connect

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

170

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

171

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

172

Development of an inert ceramic anode to reduce energy consumption in magnesium production. Final Report  

SciTech Connect

The objective of this work is to develop a dimensionally stable ceramic anode for production of magnesium metal in electrolytic cells, replacing the graphite anodes currently used by The Dow Chemical Company magnesium business. The work is based on compositional and design technology for a ceramic anode developed in the former Central Research Inorganic Laboratory. The approach selected is to use a ceramic semiconductor tube as the material to interface with the bath and gaseous atmosphere in the cell. The testing goal was to demonstrate six anodes surviving a 30 day test lifetime with acceptable wear rates and electrical performance in a laboratory scale magnesium cell test. State of the art slip casting techniques were used and advanced in the pursuit of a virtually flaw free ceramic anode shell. Novel core materials were also invented to allow for the complete, crack free fabrication of the laboratory scale anode. Two successive anodes were tested and exceeded the 30 day cell lifetime goal with excellent wear characteristics. More aggressive testing of the ceramic anode revealed that the anode had a rather narrow operating region.

NONE

1997-06-01T23:59:59.000Z

173

Ceramics for ATS industrial turbines  

SciTech Connect

US DOE and most US manufacturers of stationary gas turbines are participating in a major national effort to develop advanced turbine systems (ATS). The ATS program will achieve ultrahigh efficiencies, environmental superiority, and cost competitiveness compared with current combustion turbine systems. A major factor in the improved efficiencies of simple cycle ATS gas turbines will be higher operating efficiencies than curren engines. These temperatures strain the limits of metallic alloy and flow-path cooling technologies. Ceramics materials offer a potential alterative to cooled turbine alloys for ATS turbines due to higher melting points than metallics. This paper evaluates ceramics technology and plant economic issues for ATS industrial turbine systems. A program with the objective of demonstrating first-stage ceramic vanes in a commerical industrial turbine is also described.

Wenglarz, R.; Ali, S. [Allison Engine Co., Indianapolis, IN (United States); Layne, A. [USDOE Morgantown Energy Technology Center, WV (United States)

1996-05-01T23:59:59.000Z

174

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

175

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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

176

Electron beam welding of ceramic to metal using fore-vacuum plasma electron source  

Science Journals Connector (OSTI)

The possibility of creating ceramic-metal joints by electron beam welding is considered. The welding of ... range (5–20 Pa) using a plasma electron source. The structure and composition of the ceramic ... breakin...

A. K. Goreev; V. A. Burdovitsin; A. S. Klimov…

2012-09-01T23:59:59.000Z

177

Polypropylene/Glass Fiber Hierarchical Composites Incorporating Inorganic Fullerene-like Nanoparticles for Advanced Technological Applications  

Science Journals Connector (OSTI)

In particular, the incorporation of nanoclays to GFRPs has been reported to improve significantly the heat distortion temperature, flexural and impact strengths. ... Enhanced mech., thermal and vibration properties were obsd. in nanoclay dispersed composites over vinyl ester-glass fiber composite. ...

Ana M. Díez-Pascual; Mohammed Naffakh

2013-09-09T23:59:59.000Z

178

Glass Ceramic Formulation Data Package  

SciTech Connect

A glass ceramic waste form is being developed for treatment of secondary waste streams generated by aqueous reprocessing of commercial used nuclear fuel (Crum et al. 2012b). The waste stream contains a mixture of transition metals, alkali, alkaline earths, and lanthanides, several of which exceed the solubility limits of a single phase borosilicate glass (Crum et al. 2009; Caurant et al. 2007). A multi-phase glass ceramic waste form allows incorporation of insoluble components of the waste by designed crystallization into durable heat tolerant phases. The glass ceramic formulation and processing targets the formation of the following three stable crystalline phases: (1) powellite (XMoO4) where X can be (Ca, Sr, Ba, and/or Ln), (2) oxyapatite Yx,Z(10-x)Si6O26 where Y is alkaline earth, Z is Ln, and (3) lanthanide borosilicate (Ln5BSi2O13). These three phases incorporate the waste components that are above the solubility limit of a single-phase borosilicate glass. The glass ceramic is designed to be a single phase melt, just like a borosilicate glass, and then crystallize upon slow cooling to form the targeted phases. The slow cooling schedule is based on the centerline cooling profile of a 2 foot diameter canister such as the Hanford High-Level Waste canister. Up to this point, crucible testing has been used for glass ceramic development, with cold crucible induction melter (CCIM) targeted as the ultimate processing technology for the waste form. Idaho National Laboratory (INL) will conduct a scaled CCIM test in FY2012 with a glass ceramic to demonstrate the processing behavior. This Data Package documents the laboratory studies of the glass ceramic composition to support the CCIM test. Pacific Northwest National Laboratory (PNNL) measured melt viscosity, electrical conductivity, and crystallization behavior upon cooling to identify a processing window (temperature range) for melter operation and cooling profiles necessary to crystallize the targeted phases in the waste form.

Crum, Jarrod V.; Rodriguez, Carmen P.; McCloy, John S.; Vienna, John D.; Chung, Chul-Woo

2012-06-17T23:59:59.000Z

179

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect

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

180

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

NLE Websites -- All DOE Office Websites (Extended Search)

Journal of Modern Physics B Vol. 24, Nos. 15 & 16 (2010) 23572362 Summary: -TIC-TICDLC GRADIENT NANO-COMPOSITE FILM ON NITI ALLOY FUQIU MA, XILIANG LIU, DONG LIU and...

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

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.

182

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

SciTech Connect

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

183

21 - Improving the durability of advanced fiber-reinforced polymer (FRP) composites using nanoclay  

Science Journals Connector (OSTI)

Abstract: In this chapter, we report the findings of experimental investigations conducted on durability of glass fiber-reinforced polymer (GFRP) composites with and without the addition of montmorillonite nanoclay. First, neat and nanoclay-added epoxy systems were characterized to evaluate the extent of clay platelet exfoliation and dispersion of nanoclay. GFRP composite panels were then fabricated with neat/modified epoxy resin and exposed to six different conditions, i.e. hot-dry/wet, cold-dry/wet, ultraviolet radiation and alternate ultraviolet radiation–condensation. Room temperature condition samples were also used for baseline consideration. An improved dispersion of nanoclay and exfoliation of clay platelets were observed in 2 wt% of epoxy samples. Weight change, discoloration and significant reduction in properties were observed in all conditioned GFRP samples. However, addition of nanoclay considerably improved the durability of GFRP samples as evident from the mechanical and micrographical results in comparison to neat samples subjected to similar conditions.

S. Zainuddin; M.V. Hosur; S. Jeelani; A. Kumar; J. Trovillion

2013-01-01T23:59:59.000Z

184

Recent advances to assess mono- and multi-delaminations behaviour of aerospace composites  

Science Journals Connector (OSTI)

During the last 10 years, significant research efforts have been conducted in the aerospace field to develop a predictive fracture mechanics approach to assess the behaviour resulting from localised delamination defects. The main results of this paper will be presented in two parts. The first part addresses:• Development of specific experimental methods to monitor post-buckling delamination behaviour. • Validation of mixed mode propagation criteria and development of experimental protocol to determine material fracture mechanics parameters. • A robust numerical F.E. computation scheme (modified virtual crack extension) to assess energy released rate and mode partition along the delamination tip. Illustrations of the method will be presented through two typical configurations:• Local delamination near the surface in a monolithic composite. • Debonding between skin and honeycomb core of a sandwich structures. The second part will detail extension of the methodology proposed previously to assess failure mechanisms during static compression after impact of a monolithic composite plate. The damage morphology of an impacted composite plate is characterised by multi-delaminations with a typical helix geometry. The ruin mechanism is regarded as an elastic non-linear behaviour in the damaged area due to a progressive local buckling of delaminated plies until a coupled bending-compression failure. Damage evolution is predicted by introduction of delaminations in a 3D F.E. model with non-penetration contact conditions and elastic properties degradation of the damaged plies. Techniques to manage a mesh with multi-delaminations will be detailed.

D. Guédra-Degeorges

2006-01-01T23:59:59.000Z

185

Irradiation study of PNNL synthesized glass-ceramics  

SciTech Connect

Two types of glass-ceramic were investigated: (1) for immobilization of Ln, alkali, and alkaline earths (GC4); and (2) same as above + high (7%) molybdenum content (Mo7) multiphase specimens. The purpose was to study the radiation stability of PNNL synthesized glass-ceramics and changes in microstructure/phase composition.

Kossoy-simakov, Anna-eden [Los Alamos National Laboratory; Tang, Ming [Los Alamos National Laboratory; Valdez, James A [Los Alamos National Laboratory; Usov, Igor O [Los Alamos National Laboratory; Sickafus, Kurt E [Los Alamos National Laboratory

2011-01-18T23:59:59.000Z

186

Novel Processing of Unique Ceramic-Based Nuclear Materials and Fuels  

SciTech Connect

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

187

Novel Processing to Produce Polymer/Ceramic Nanocomposites by Atomic Layer Deposition  

E-Print Network (OSTI)

- scale ceramic inclusions within a polymer matrix was demon- strated. Micron-sized high density scale, but ceramics are not homogeneously dispersed in the polymer matrix at a nanoscopic level7 of this novel technique, the mechanical and barrier properties of this kind of polymer/ceramic nano- composite

George, Steven M.

188

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

SciTech Connect

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

189

CERAMIC WASTE FORM DATA PACKAGE  

SciTech Connect

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

190

Applications of Ceramic Materials  

Science Journals Connector (OSTI)

The use of ceramic materials in science and industry is becoming increasingly widespread. As discussed in Chap. 4, ceramic materials have important advantages over metals and polymers in electronic devices at ...

Murat Bengisu

2001-01-01T23:59:59.000Z

191

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

SciTech Connect

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

192

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

193

8 - Ceramic materials  

Science Journals Connector (OSTI)

Ceramic materials, manufactured from fired clay, have been used in construction since at least 4000 BC in Egypt, and represent the earliest manufactured building materials. Whilst the strict definition of ceramics includes glass, stone and cement, this chapter deals only with the traditional ceramics based on clays. The variety of traditional ceramic products used within the building industry arises from the wide range of natural and blended clays used for their production. The roof of the spectacular Sydney Opera House (Fig. 8.1) is surfaced with white ceramic tiles which reflect the changing light associated with the time of day.

Arthur Lyons

2006-01-01T23:59:59.000Z

194

Improvement of the detection limit for biosensors: Advances on the optimization of biocomposite composition  

Science Journals Connector (OSTI)

Abstract In this work the application of advanced characterization techniques in the development of amperometric biosensors based on biocomposites is described. The optimization of the conductive particle distribution and the amount of the biological material inside the biomaterial have allowed an improvement of the electrochemical properties, regarding the electroanalytical properties such as signal stability and limit of detection. The high signal-to-noise ratio obtained in the electrochemical transduction has allowed enhancing the limit of detection of the biosensor. In the present study, it has been demonstrated the feasibility of electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) for the characterization and optimization of biosensors based on graphite–epoxy–enzyme, using an enzyme model. The optimum biocomposite proportion based on graphite–epoxy which incorporates the enzyme glucose oxidase (GOD) on the matrix ranges between 16% and 17% of graphite using 1% and 2% of enzyme. This range provides the optimal electroanalytical properties. Low limit of detection and good sensitivity have been achieved. Furthermore, confocal laser scanning microscopy was used to visualize the enzyme distribution onto the surface electrode.

R. Montes; J. Bartrolí; M. Baeza; F. Céspedes

2015-01-01T23:59:59.000Z

195

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

196

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

197

NONLOCAL COMPUTATIONAL METHODS APPLIED TO COMPOSITE STRUCTURES  

E-Print Network (OSTI)

to model the degradation of organic or ceramic matrix composites structures (OMC or CMC) even under simple description of heterogeneous materia ls like organic or ceramic matrix composites. New sophisticatedNONLOCAL COMPUTATIONAL METHODS APPLIED TO COMPOSITE STRUCTURES N. GERMAIN1, F. FEYEL1 and J. BESSON

Boyer, Edmond

198

The Role of Ceramics in a Resurgent Nuclear Industry  

SciTech Connect

With fuel oil and natural gas prices near record highs and worldwide energy demands increasing at an alarming rate, there is growing interest in revitalization of the nuclear power industry within the United States and across the globe. Ceramic materials have long played a very important part in the commercial nuclear industry with applications throughout the entire fuel cycle; from fuel fabrication to waste stabilization. As the international community begins to look at advanced fuel cycles that minimize waste and increase proliferation resistance, ceramic materials will play an even larger role. Many of the advanced reactor concepts being evaluated operate at high-temperature requiring the use of durable, heat-resistant materials. Ceramic fuels are being investigated for a variety of Generation IV reactor concepts. These include the traditional TRISO-coated particles as well as advanced inert-matrix fuels. In order to minimize wastes and legacy materials, ceramic processes are also being applied to fuel reprocessing operations. Ceramic materials continue to provide a vital contribution in ''closing the fuel cycle'' by stabilization of associated low-level and high-level wastes in highly durable grout, ceramics, and glass. In the next five years, programs that are currently in the conceptual phase will begin laboratory- and engineering-scale demonstrations. This will require production-scale demonstrations of several ceramic technologies from fuel form development to advanced stabilization methods. Within the next five to ten years, these demonstrations will move to even larger scales and will also include radioactive demonstrations of these advanced technologies. These radioactive demonstrations are critical to program success and will require advances in ceramic materials associated with nuclear energy applications.

Marra, J

2006-02-28T23:59:59.000Z

199

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

200

Oxygen Transport Ceramic Membranes  

SciTech Connect

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

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

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

202

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 zirconica coating; the crack ERR for the composite coating is shown to be 30% lower than that for a uniform

Wadley, Haydn

203

NETL: Advanced Research - Materials  

NLE Websites -- All DOE Office Websites (Extended Search)

High Performance Materials > Chrome Oxide Refractory High Performance Materials > Chrome Oxide Refractory Advanced Research High Performance Materials Chrome Oxide Refractory One notable NETL success is the development of a chrome oxide refractory material capable of working in slagging gasifier conditions. In this project, researchers first determined that one of the major failure mechanisms for chrome oxide refractories exposed to the intense heat and corrosive environment was spalling, or the chipping or flaking of refractory material from an exposed face. They used this information to formulate a high-chrome oxide refractory composition that resists spalling, resulting in a refractory with a longer service life in the gasifier. Inside an ultrasupercritical (USC) pulverized coal power plant, materials are exposed to temperatures up to 760°C and pressures up to 5,000 psi. Operating a USC system can improve power plant efficiency up to 47% and reduce emissions. However, finding boiler and turbine materials that can hold up under extreme conditions requires new high-temperature metal alloys and ceramic coatings, as well as computational modeling research to optimize the processing of these materials. Advanced Research Materials Development program successes in this area include the following:

204

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

SciTech Connect

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

205

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

206

Arnold Schwarzenegger SPECTRALLY ENHANCED CERAMIC  

E-Print Network (OSTI)

Arnold Schwarzenegger Governor SPECTRALLY ENHANCED CERAMIC INCANDESCENT EMITTER Prepared For ENHANCED CERAMIC INCANDESCENT EMITTER EISG AWARDEE SONSIGHT INC. 17609 Clinton Drive Accokeek, MD 20607

207

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 Ă?yieldĂ? strength for ceramic matrix

California at Los Angeles, University of

208

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

209

Oxygen Transport Ceramic Membranes  

SciTech Connect

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

210

Corrosion and its effect on mechanical properties of materials for advanced combustion systems  

SciTech Connect

Conceptual designs of advanced combustion systems that utilize coal as a feedstock require high-temperature furnaces and heat transfer surfaces that can operate at temperatures much higher than those prevalent in current coal-fired power plants. The combination of elevated temperatures and hostile combustion environments necessitates development and application of advanced ceramic materials in these designs. The objectives of the present program are to evaluate (a) the chemistry of gaseous and condensed products that arise during combustion of coal; (b) the corrosion behavior of candidate materials in air, slag and salt environments for application in the combustion environments; and (c) the residual mechanical properties of the materials after corrosion. The program emphasizes temperatures in the range of 1000-1400{degrees}C for ceramic materials and 600-1000{degrees}C for metallic alloys. Coal/ash chemistries developed on the basis of thermodynamic/kinetic calculations, together with slags from actual combustors, are used in the program. The materials being evaluated include monolithic silicon carbide from several sources: silicon, nitride, silicon carbide in alumina composites, silicon carbide fibers in a silicon carbide- matrix composite, and some advanced nickel-base alloys. The paper presents results from an ongoing program on corrosion performance of candidate ceramic materials exposed to air, salt and slag environments and their affect on flexural strength and energy absorbed during fracture of these materials.

Natesan, K. [Argonne National Lab., IL (United States); Freeman, M.; Mathur, M. [Pittsburgh Energy Technology Center, Pittsburgh, PA (United States)

1996-05-01T23:59:59.000Z

211

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect

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

212

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

213

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

214

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

215

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

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

216

Oxygen Transport Ceramic Membranes  

SciTech Connect

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

217

Development of nondestructive evaluation methods for ceramic coatings.  

SciTech Connect

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

218

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

219

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

220

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

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

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

222

Design considerations for a ceramic fabric radiator  

SciTech Connect

The design of an Advanced Ceramic Fabric (ACF) thermal management device for use in both interplanetary and near-earth space must consider several important aspects of the environment. First, the radiation field at various locations is dominated by a proton component which deposits its energy on the surface of the device. Second, the ACF materials, as well as pressure liner materials, must also be compatible with the working fluids selected for the system. Third, the fluid dynamics and heat transfer characteristics of this device should be adequately characterized. With the proper consideration of materials and operating conditions, the Bubble Membrane Radiator (BMR) may be utilized for several advanced space missions. 17 refs.

Pauley, K.A.; Webb, B.J. (Pacific Northwest Lab., Richland, WA (USA)); Klein, A.C. (Oregon State Univ., Corvallis, OR (USA). Dept. of Nuclear Engineering)

1990-04-01T23:59:59.000Z

223

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect

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

224

No Ceramics Age?  

Science Journals Connector (OSTI)

The utilization of ceramic materials by man is probably as old as human civilization itself. Stone, obsidian, clay, quartz, and mineral ores are as much a part of the history of mankind as the products which h...

Rolf E. Hummel

1998-01-01T23:59:59.000Z

225

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect

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

226

Developments in Oxide Fiber Composites Frank W. Zokw  

E-Print Network (OSTI)

are contingent on the development of durable high-per- formance ceramic composites. With recent discoveries, and toughness, continuous-fiber ceramic composites (CFCCs) offer the greatest potential for enabling elevations that are volatilized by oxidation after composite fabrica- tion, leaving a narrow gap at the fiber­matrix boundary (Fig

Zok, Frank

227

METC ceramic corrosion/erosion studies: turbine-material screening tests in high-temperature, low-Btu, coal-derived-gas combustion products  

SciTech Connect

The Morgantown Energy Technology Center, through its Ceramics Corrosion/Erosion Studies, has participated in the United States Department of Energy's High-Temperature Turbine Technology Program, Ceramic Technology Readiness. The program's overall objective is to advance the turbine firing temperature to a range of 2600/sup 0/ to 3000/sup 0/F (1700 to 1922K) with a reasonable service life using coal or coal-derived fuel. The Ceramics Corrosion/Erosion Studies' major objective was to conduct a screening test for several ceramic materials to assess their probability of survival in turbine applications. The materials were exposed to combustion products from low heating value coal-derived gas and air at several high temperatures and velocities. The combustion product composition and temperatures simulated actual environment that may be found in stationary power generating gas turbines except for the pressure levels. The results of approximately 1000 hours of accumulative exposure time of material at the specific test conditions are presented in this report.

Nakaishi, C.V.; Waltermire, D.M.; Hawkins, L.W.; Jarrett, T.L.

1982-05-01T23:59:59.000Z

228

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

229

The qualification of advanced composite pipe for use in fire water deluge systems on open type offshore oil platforms  

SciTech Connect

Different types of FIBERBOND{reg_sign} pipe in the dry condition and with a butt and strap joint were subjected to a controlled fire for fire endurance evaluation. Testing adheres to a modification of the ASTM 1173-95 guideline, which simulates the development of an actual hydrocarbon fire. For a fire water deluge system, the pipe is in the dry condition approximately one to three minutes during an actual hydrocarbon fire. Preliminary testing shows that composite pipe is able to withstand this exposure to fire for the five minute duration of the test. This is achieved with modifying the chemical composition of the composite pipe and in some cases, adding an additional structural component to the overall pipe. Therefore, composite pipe could be used for the deluge fire system of an offshore oil platform.

Lea, R.H. [Specialty Plastics, Inc., Baton Rouge, LA (United States); Stubblefield, M.A.; Pang, S.S. [Louisiana State Univ., Baton Rouge, LA (United States). Dept. of Mechanical Engineering

1996-12-01T23:59:59.000Z

230

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

231

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

232

Sintering and crystallization of akermanite-based glass–ceramics  

Science Journals Connector (OSTI)

Akermanite-based glass–ceramics were successfully produced from the SiO2–Al2O3–B2O3–MgO–CaO–Na2O–F system via sintering and crystallization of glass-powder compacts at low temperatures between 750 and 800 °C. The experimental results indicated that the amount of Al2O3 in the parent glass composition is seemingly a key factor with regard to the potential of this system to crystallize into a mono-mineral akermanite glass–ceramic. The aesthetics and the mechanical, the chemical and the thermal properties of the produced glass–ceramics in conjunction with the evaluation of the economic processing route proposed qualify these glass–ceramics for further investigation as potential materials suitable for applications in restorative dentistry.

J.M.G. Ventura; D.U. Tulyaganov; S. Agathopoulos; J.M.F. Ferreira

2006-01-01T23:59:59.000Z

233

Advanced Materials  

NLE Websites -- All DOE Office Websites (Extended Search)

Advanced Materials Advanced Materials Advanced Materials Express Licensing Active Terahertz Metamaterial Devices Express Licensing Anion-Conducting Polymer, Composition, And Membrane Express Licensing Analysis Of Macromolecule, Liggands And Macromolecule-Lingand Complexes Express Licensing Carbon Microtubes Express Licensing Chemical Synthesis Of Chiral Conducting Polymers Express Licensing Forming Adherent Coatings Using Plasma Processing Express Licensing Hydrogen Scavengers Express Licensing Laser Welding Of Fused Quartz Express Licensing Multiple Feed Powder Splitter Negotiable Licensing Boron-10 Neutron Detectors for Helium-3 Replacement Negotiable Licensing Insensitive Extrudable Explosive Negotiable Licensing Durable Fuel Cell Membrane Electrode Assembly (MEA) Express Licensing Method of Synthesis of Proton Conducting Materials

234

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect

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

235

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

236

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

237

CERAMIC MEMBRANE ENABLING TECHNOLOGY FOR IMPROVED IGCC EFFICIENCY  

SciTech Connect

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

238

Ceramic matrix composites containing carbon nanotubes  

Science Journals Connector (OSTI)

Organic surfactants or dispersants can be also used to tailor surface...77–79] and cetyltrimethylammonium bromide (CTAB) [80, 81...], whilst common anionic surfactants include PAA (polyacrylic acid) [77, 78], SDS...

Johann Cho; Aldo R. Boccaccini; Milo S. P. Shaffer

2009-04-01T23:59:59.000Z

239

E-Print Network 3.0 - advanced lost foam Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

of Fusion Energy, Madison WI, Sept. 14-16, 2004. Summary: ratios. Based on these recent innovations and advances, we suggest the development of ceramic foams... ., Pacoima...

240

3-D woven, mullite matrix, composite filter  

SciTech Connect

Westinghouse, with Techniweave as a major subcontractor, is conducting a three-phase program aimed at providing advanced candle filters for a 1996 pilot scale demonstration in one of the two hot gas filter systems at Southern Company Service`s Wilsonville PSD Facility. The Base Program (Phases I and II) objective is to develop and demonstrate the suitability of the Westinghouse/Techniweave next generation composite candle filter for use in Pressurized Fluidized Bed Combustion (PFBC) and/or Integrated Gasification Combined Cycle (IGCC) power generation systems. The Optional Task (Phase M, Task 5) objective is to fabricate, inspect and ship to Wilsonville Hot gas particulate filters are key components for the successful commercializaion of advanced coal-based power-generation systems such as Pressurized Fluidized-bed Combustion (PFBC), including second-generation PFBC, and Integrated Gasification Combined Cycles (IGCC). Current generation monolithic ceramic filters are subject to catastrophic failure because they have very low resistance to crack propagation. To overcome this problem, a damage-tolerant ceramic filter element is needed.

Lane, J.E.; Painter, C.J.; Radford, K.C. LeCostaouec, J.F.

1995-12-01T23:59:59.000Z

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

Composite materials for fusion applications  

SciTech Connect

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

242

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

243

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

244

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

245

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect

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

246

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect

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

247

Microwave processing of ceramics  

SciTech Connect

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

248

Microwave processing of ceramics  

SciTech Connect

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

249

CERAMIC MEMBRANE ENABLING TECHNOLOGY FOR IMPROVED IGCC EFFICIENCY  

SciTech Connect

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

250

The chemical vapor deposition of zirconium carbide onto ceramic substrates  

SciTech Connect

Zirconium carbide is an attractive ceramic material due to its unique properties such as high melting point, good thermal conductivity, and chemical resistance. The controlled preparation of zirconium carbide films of superstoichiometric, stoichiometric, and substoichiometric compositions has been achieved utilizing zirconium tetrachloride and methane precursor gases in an atmospheric pressure high temperature chemical vapor deposition system.

Glass, John A, Jr.; Palmisiano, Nick, Jr.; Welsh, R. Edward

1999-07-01T23:59:59.000Z

251

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

252

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

253

High temperature alkali corrosion of ceramics in coal gas  

SciTech Connect

High temperature alkali corrosion has been known to cause premature failure of ceramic components used in advanced high temperature coal combustion systems such as coal gasification and clean-up, coal fired gas turbines, and high efficiency heat engines. The objective of this research is to systematically evaluate the alkali corrosion resistance of the most commonly used structural ceramics including silicon carbide, silicon nitride, cordierite, mullite, alumina, aluminum titanate, zirconia, and fireclay glass. The study consists of identification of the alkali reaction products (phase equilibria) and the kinetics of the alkali reactions as a function of temperature and time.

Pickrell, G.R.; Sun, T.; Brown, J.J.

1992-05-27T23:59:59.000Z

254

Application of organosilicon pre-sic polymer technology to optimize rapid prototyping of ceramic components  

SciTech Connect

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

255

Oxygen Transport Ceramic Membranes  

SciTech Connect

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

256

STATEMENT OF CONSIDERATIONS REQUEST BY SOLAR TURBINES INCORPORATED FOR AN ADVANCE WAIVER  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

FC02-00CH11049; W(A)-01-003; CH-1056 FC02-00CH11049; W(A)-01-003; CH-1056 As set out in attached waiver petition and in subsequent discussions with Solar Turbines Incorporated (Solar), Solar has requested an advance waiver of domestic and foreign patent rights for all subject inventions made under the above identified cooperative agreement by its employees and its subcontractors' employees regardless of tier, except inventions made by subcontractors eligible to retain title to inventions pursuant to P.L. 96-517, as amended, or National Laboratories. Under this agreement, Solar expects to develop and demonstrate a significantly improved combustion system for its Mercury 50 advanced industrial gas turbine by selectively incorporating advanced alloys, coatings, and composite and monolithic ceramics into

257

STATEMENT OF CONSIDERATIONS REQUEST BY GENERAL ELECTRIC COMPANY FOR AN ADVANCE WAIVER  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

31 2002 14:43 FR IPL DOE CH 630 252 2779 TO RGCP-HQ P.02/03 31 2002 14:43 FR IPL DOE CH 630 252 2779 TO RGCP-HQ P.02/03 STATEMENT OF CONSIDERATIONS REQUEST BY GENERAL ELECTRIC COMPANY FOR AN ADVANCE WAIVER OF PATENT RIGHTS UNDER DOE COOPERATIVE AGREEMENT NO. DE- FC02-00CH11047 ENTITLED "MELT INFILTRATED CERAMIC MATRIX COMPOSITES FOR SHROUDS AND COMBUSTOR LINERS OF ADVANCED INDUSTRIAL GAS TURBINES"; W(A)-01-030; CH-1077 As set out in the attached waiver petition and in subsequent discussions with DOE Patent Counsel, General Electric Company (GE) has requested an advance waiver of domestic and foreign patent rights for all subject inventions made under the above-identified cooperative agreement by its employees and its subcontractors' employees, regardless of tier, except inventions made by subcontractors eligible to retain title to inventions pursuant to P.L. 96-517,

258

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

259

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

260

Ceramics for fusion applications  

SciTech Connect

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

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

Advanced hot-gas filter development. Topical report, September 30, 1994--May 31, 1996  

SciTech Connect

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

262

Dielectric behavior of barium modified strontium bismuth titanate ceramic  

SciTech Connect

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

263

NOVEL CERAMIC MEMBRANE FOR HIGH TEMPERATURE CARBON DIOXIDE SEPARATION  

SciTech Connect

This project is aimed at demonstrating technical feasibility for a lithium zirconate based dense ceramic membrane for separation of carbon dioxide from flue gas at high temperature. The research work conducted in this reporting period was focused on several fundamental issues of lithium zirconate important to the development of the dense inorganic membrane. These fundamental issues include material synthesis of lithium zirconate, phases and microstructure of lithium zirconate and structure change of lithium zirconate during sorption/desorption process. The results show difficulty to prepare the dense ceramic membrane from pure lithium zirconate, but indicate a possibility to prepare the dense inorganic membrane for carbon dioxide separation from a composite lithium zirconate.

Jerry Y.S. Lin; Jun-ichi Ida

2001-03-01T23:59:59.000Z

264

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

265

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect

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

266

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

267

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

268

Fabric composite heat pipe technology development  

SciTech Connect

Testing has been performed on a variety of fabric composite technology feasibility issues. These include an evaluation of the effective radiation heat transfer rate from a heated metallic surface covered by a ceramic fabric with the intent of determining the effective emissivity'' of the combination of materials, studies of the wicking properties of ceramic fabrics, and the construction of fabric composite heat pipes to test their working properties under both steady state and transient conditions. Results of these experiments shown that fabric composite combinations have greatly enhanced effective emissivities'' resulting from the increases surface area of the fabric, ceramic fabrics can work very well as the wick for heat pipes, ceramic fabric heat pipes have been demonstrated to operate under typical space conditions, and large mass reductions are possible by using fabric composite heat pipes for heat rejection radiator systems.

Klein, A.C.; Gulshan-Ara, Z.; Kiestler, W.; Snuggerud, R.; Marks, T.S. (Department of Nuclear Engineering, Oregon State University, Corvallis, Oregon 97331 (United States))

1993-01-10T23:59:59.000Z

269

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

270

Development of Cost-Effective Low-Permeability Ceramic and Refractory Components for Aluminum Melting and Casting  

SciTech Connect

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

271

Pleated Ceramic Fiber Diesel Particulate Filter | Department...  

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

Pleated Ceramic Fiber Diesel Particulate Filter Pleated Ceramic Fiber Diesel Particulate Filter 2005 Diesel Engine Emissions Reduction (DEER) Conference Presentations and Posters...

272

Radiation damage evolution in ceramics. | EMSL  

NLE Websites -- All DOE Office Websites (Extended Search)

defect accumulation and dynamic annealing in a number of ceramics, such as silicon carbide, zircon and zirconia. Under energetic particle irradiation, ceramics can undergo...

273

Nanophase Glass Ceramics for Capacitive Energy Storage.  

E-Print Network (OSTI)

??Glass ceramics are candidate dielectric materials for high energy storage capacitors. Since energy density depends primarily on dielectric permittivity and breakdown strength, glass ceramics with… (more)

Rangarajan, Badri

2009-01-01T23:59:59.000Z

274

Analyse micromcanique de la rupture des composites cramiques P. Prs, L. Anquez et J. Jamet  

E-Print Network (OSTI)

The fracture mechanic analysis of a basic ceramic-ceramic composite (filament + coating) is based on two main of the matrix explain the non linear behaviour of such composites. They are discussed in relation213 Analyse micromécanique de la rupture des composites céramiques P. Pérès, L. Anquez et J. Jamet

Boyer, Edmond

275

Mullite/Alumina Mixtures for Use as Porous Matrices in Oxide Fiber Composites  

E-Print Network (OSTI)

ceramic composites. Conditions for the deflection of a matrix crack at a fiber-matrix interface are used to enable damage tolerance in continuous-fiber ceramic composites (CFCCs) has emerged as a new paradigm between matrix structure and composite performance are understood presently at only a rudimentary level

Zok, Frank

276

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

277

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 % 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.

Becher, Paul F. (Oak Ridge, TN); Funkenbusch, Eric F. (White Bear Lake, MN)

1990-01-01T23:59:59.000Z

278

Braze material for joining ceramic to metal and ceramic to ceramic surfaces and joined ceramic to metal and ceramic to ceramic article  

DOE Patents (OSTI)

An improved active metal braze filler material is provided in which the coefficient of thermal expansion of the braze filler is more closely matched with that of the ceramic and metal, or two ceramics, to provide ceramic to metal, or ceramic to ceramic, sealed joints and articles which can withstand both high temperatures and repeated thermal cycling without failing. The braze filler material comprises a mixture of a material, preferably in the form of a powder, selected from the group consisting of molybdenum, tungsten, silicon carbide and mixtures thereof, and an active metal filler material selected from the group consisting of alloys or mixtures of nickel and titanium, alloys or mixtures of nickel and zirconium, alloys or mixtures of nickel, titanium, and copper, alloys or mixtures of nickel, titanium, and zirconium, alloys or mixtures of niobium and nickel, alloys or mixtures of niobium and zirconium, alloys or mixtures of niobium and titanium, alloys or mixtures of niobium, titanium, and nickel, alloys or mixtures of niobium, zirconium, and nickel, and alloys or mixtures of niobium, titanium, zirconium, and nickel. The powder component is selected such that its coefficient of thermal expansion will effect the overall coefficient of thermal expansion of the braze material so that it more closely matches the coefficients of thermal expansion of the ceramic and metal parts to be joined. 3 figures.

Hunt, T.K.; Novak, R.F.

1991-05-07T23:59:59.000Z

279

Braze material for joining ceramic to metal and ceramic to ceramic surfaces and joined ceramic to metal and ceramic to ceramic article  

DOE Patents (OSTI)

An improved active metal braze filler material is provided in which the coefficient of thermal expansion of the braze filler is more closely matched with that of the ceramic and metal, or two ceramics, to provide ceramic to metal, or ceramic to ceramic, sealed joints and articles which can withstand both high temperatures and repeated thermal cycling without failing. The braze filler material comprises a mixture of a material, preferably in the form of a powder, selected from the group consisting of molybdenum, tungsten, silicon carbide and mixtures thereof, and an active metal filler material selected from the group consisting of alloys or mixtures of nickel and titanium, alloys or mixtures of nickel and zirconium, alloys or mixtures of nickel, titanium, and copper, alloys or mixtures of nickel, titanium, and zirconium, alloys or mixtures of niobium and nickel, alloys or mixtures of niobium and zirconium, alloys or mixtures of niobium and titanium, alloys or mixtures of niobium, titanium, and nickel, alloys or mixtures of niobium, zirconium, and nickel, and alloys or mixtures of niobium, titanium, zirconium, and nickel. The powder component is selected such that its coefficient of thermal expansion will effect the overall coefficient of thermal expansion of the braze material so that it more closely matches the coefficients of thermal expansion of the ceramic and metal parts to be joined.

Hunt, Thomas K. (Ann Arbor, MI); Novak, Robert F. (Farmington Hills, MI)

1991-01-01T23:59:59.000Z

280

Short courses in Composite Materials  

E-Print Network (OSTI)

Short courses in Composite Materials Overview The ability to tailor the material properties used. Combining the adaptability of composites with clear weight savings, whilst tailoring materials properties Airbus and Glyndr University, the Advanced Composites Training and Development Centre educates current

Davies, John N.

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

High-Temperature Structural Ceramics  

Science Journals Connector (OSTI)

...application of ceramic hardware in gas turbine hot-flow-path components to...could survive the rigors ofthe gas turbine envi-ronment in any meaningful...ceramic components could survive in a gas turbine environment, other pro-grams...

R. Nathan Katz

1980-05-23T23:59:59.000Z

282

Method of forming ceramic bricks  

DOE Patents (OSTI)

A method for forming free standing ceramic bricks for use as tritium breeder material is disclosed. Aqueous solutions of sodium carbonate and potassium carbonate are mixed with an organic hydrocolloid dispersion and powdered lithium carbonate, spray dried, and ceramic bricks formed by molding in a die and firing.

Poeppel, R.B.; Claar, T.D.; Silkowski, P.

1987-04-22T23:59:59.000Z

283

The Use of Large Transparent Ceramics in a High Powered, Diode Pumped Solid State Laser  

SciTech Connect

The advent of large transparent ceramics is one of the key enabling technological advances that have shown that the development of very high average power compact solid state lasers is achievable. Large ceramic neodymium doped yttrium aluminum garnet (Nd:YAG) amplifier slabs are used in Lawrence Livermore National Laboratory's (LLNL) Solid State Heat Capacity Laser (SSHCL), which has achieved world record average output powers in excess of 67 kilowatts. We will describe the attributes of using large transparent ceramics, our present system architecture and corresponding performance; as well as describe our near term future plans.

Yamamoto, R; Bhachu, B; Cutter, K; Fochs, S; Letts, S; Parks, C; Rotter, M; Soules, T

2007-09-24T23:59:59.000Z

284

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect

In the present quarter, the possibility of using a more complex interfacial engineering approach to the development of reliable and stable oxygen transport perovskite ceramic membranes/metal seals is discussed. Experiments are presented and ceramic/metal interactions are characterized. Crack growth and fracture toughness of the membrane in the reducing conditions are also discussed. Future work regarding this approach is proposed are evaluated for strength and fracture in oxygen gradient conditions. Oxygen gradients are created in tubular membranes by insulating the inner surface from the reducing environment by platinum foils. Fracture in these test conditions is observed to have a gradient in trans and inter-granular fracture as opposed to pure trans-granular fracture observed in homogeneous conditions. Fracture gradients are reasoned to be due to oxygen gradient set up in the membrane, variation in stoichiometry across the thickness and due to varying decomposition of the parent perovskite. The studies are useful in predicting fracture criterion in actual reactor conditions and in understanding the initial evolution of fracture processes.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2003-01-01T23:59:59.000Z

285

Optical method and apparatus for detection of defects and microstructural changes in ceramics and ceramic coatings  

DOE Patents (OSTI)

Apparatus detects defects and microstructural changes in hard translucent materials such as ceramic bulk compositions and ceramic coatings such as after use under load conditions. The beam from a tunable laser is directed onto the sample under study and light reflected by the sample is directed to two detectors, with light scattered with a small scatter angle directed to a first detector and light scattered with a larger scatter angle directed to a second detector for monitoring the scattering surface. The sum and ratio of the two detector outputs respectively provide a gray-scale, or "sum" image, and an indication of the lateral spread of the subsurface scatter, or "ratio" image. This two detector system allows for very high speed crack detection for on-line, real-time inspection of damage in ceramic components. Statistical image processing using a digital image processing approach allows for the quantative discrimination of the presence and distribution of small flaws in a sample while improving detection reliability. The tunable laser allows for the penetration of the sample to detect defects from the sample's surface to the laser's maximum depth of penetration. A layered optical fiber directs the incoming laser beam to the sample and transmits each scattered signal to a respective one of the two detectors.

Ellingson, William A. (Naperville, IL); Todd, Judith A. (Hinsdale, IL); Sun, Jiangang (Westmont, IL)

2001-01-01T23:59:59.000Z

286

High pressure ceramic heat exchanger  

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 header assembly when used with recuperators reduces the brittle effect of a portion of the ceramic components. Thus, the present header assembly 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 header assembly is comprised of a first ceramic member, a second ceramic member, a reinforcing member being in spaced relationship to the first ceramic member and the second ceramic member. The header assembly is further comprised of a refractory material disposed in contacting relationship with the first ceramic member, the second ceramic member and the reinforcing member and having a strengthening member wrapped around the refractory material. The present header assembly provides a high strength load bearing header assembly having good thermal cycling characteristics, good resistance to a corrosive environment and good steady state strength at elevated temperatures.

Harkins, Bruce D. (San Diego, CA); Ward, Michael E. (Poway, CA)

1999-01-01T23:59:59.000Z

287

High pressure ceramic heat exchanger  

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 header assembly when used with recuperators reduces the brittle effect of a portion of the ceramic components. Thus, the present header assembly 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 header assembly is comprised of a first ceramic member, a second ceramic member, a strengthening reinforcing member being in spaced relationship to the first ceramic member and the second ceramic member. The header assembly is further comprised of a refractory material disposed in contacting relationship with the first ceramic member, the second ceramic member and the strengthening reinforcing member. The present header assembly provides a high strength load bearing header assembly having good thermal cycling characteristics, good resistance to a corrosive environment and good steady state strength at elevated temperatures.

Harkins, Bruce D. (San Diego, CA); Ward, Michael E. (Poway, CA)

1998-01-01T23:59:59.000Z

288

High pressure ceramic heat exchanger  

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 header assembly when used with recuperators reduces the brittle effect of a portion of the ceramic components. Thus, the present header assembly 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 header assembly is comprised of a first ceramic member, a second ceramic member, a strengthening reinforcing member being in spaced relationship to the first ceramic member and the second ceramic member. The header assembly is further comprised of a refractory material disposed in contacting relationship with the first ceramic member, the second ceramic member and the strengthening reinforcing member. The present header assembly provides a high strength load bearing header assembly having good thermal cycling characteristics, good resistance to a corrosive environment and good steady state strength at elevated temperatures. 5 figs.

Harkins, B.D.; Ward, M.E.

1998-09-22T23:59:59.000Z

289

Impact of Honeycomb Ceramics Geometrical Cell Design on Urea...  

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

Honeycomb Ceramics Geometrical Cell Design on Urea SCR System Impact of Honeycomb Ceramics Geometrical Cell Design on Urea SCR System Honeycomb ceramic substrates with 3 cell...

290

Polymer-Ceramic MEMS Bimorphs as Thermal Infrared Sensors  

E-Print Network (OSTI)

of thermal expansion between polymers and ceramics. However,of thermal expansion for selected ceramics, metals, andof thermal expansion for selected ceramics, metals, and

Warren, Clinton Gregory

2010-01-01T23:59:59.000Z

291

Fiber-Reinforced Polymer Composites: Pursuing the Promise | Department...  

Energy Savers (EERE)

Fiber-Reinforced Polymer Composites: Pursuing the Promise Fiber-Reinforced Polymer Composites: Pursuing the Promise High-strength, lightweight advanced composites will deliver a...

292

Compound transparent ceramics and methods of preparation thereof  

DOE Patents (OSTI)

According to one embodiment, a method for forming a composite transparent ceramic preform includes forming a first suspension of oxide particles in a first solvent which includes a first dispersant but does not include a gelling agent, adding the first suspension to a first mold of a desired shape, and uniformly curing the first suspension in the first mold until stable. The method also includes forming a second suspension of oxide particles in a second solvent which includes a second dispersant but does not include a gelling agent, adding the second suspension to the stable first suspension in a second mold of a desired shape encompassing the first suspension and the second suspension, and uniformly curing the second suspension in the second mold until stable. Other methods for forming a composite transparent ceramic preform are also described according to several other embodiments. Structures are also disclosed.

Hollingsworth, Joel P.; Kuntz, Joshua D.; Soules, Thomas F.; Landingham, Richard L.

2012-12-11T23:59:59.000Z

293

Joining of ceramics of different biofunction by hot isostatic pressing  

SciTech Connect

Monolithic zirconia (Z) and zirconia-hydroxyapatite (Z/HA) composites were joined by cold isostatic pressing (CIP at 300 MPa) and subsequently by glass-encapsulated hot isostatic pressing (HIP at 1225 C, 1 h and 200 MPa). The physical and mechanical properties of the materials were measured. The fracture surface was studied using a light microscope. The results indicate a strength level of the joint similar to that of the corresponding composite material (Z/HA), 845 and 860 MPa, respectively. Similar experiments with monolithic alumina (A) and alumina-hydroxyapatite (A/HA) were carried out without success. Cracking occurred in the joint area during the cold isostatic pressing process. It seems that ceramics with high green strength and similar green density are essential when joining ceramics by combined CIP and HIP processes.

Li, Jianguo (Karolinska Inst., Huddinge (Sweden). Center for Dental Technology and Biomaterials); Harmansson, L. (Doxa Certex AB, Uppsala (Sweden)); Soeremark, R. (Karolinska Inst., Huddinge (Sweden). Dept. of Prosthodontics)

1993-10-01T23:59:59.000Z

294

Ultra low thermal expansion, highly thermal shock resistant ceramic  

DOE Patents (OSTI)

Three families of ceramic compositions having the given formula: .phi..sub.1+X Zr.sub.4 P.sub.6-2X Si.sub.2X O.sub.24, .phi..sub.1+X Zr.sub.4-2X Y.sub.2X P.sub.6 O.sub.24 and .phi..sub.1+X Zr.sub.4-X Y.sub.X P.sub.6-2X Si.sub.X O.sub.24 wherein .phi. is either Strontium or Barium and X has a value from about 0.2 to about 0.8 have been disclosed. Ceramics formed from these compositions exhibit very low, generally near neutral, thermal expansion over a wide range of elevated temperatures.

Limaye, Santosh Y. (1440 Sandpiper Cir. #38, Salt Lake City, UT 84117)

1996-01-01T23:59:59.000Z

295

Method for preparing configured silicon carbide whisker-reinforced alumina ceramic articles  

DOE Patents (OSTI)

A ceramic article of alumina reinforced with silicon carbide whiskers suitable for the fabrication into articles of complex geometry are provided by pressureless sintering and hot isostatic pressing steps. In accordance with the method of the invention a mixture of 5 to 10 vol. % silicon carbide whiskers 0.5 to 5 wt. % of a sintering aid such as yttria and the balance alumina powders is ball-milled and pressureless sintered in the desired configuration in the desired configuration an inert atmosphere at a temperature of about 1800.degree. C. to provide a self-supporting configured composite of a density of at least about 94% theoretical density. The composite is then hot isostatically pressed at a temperature and pressure adequate to provide configured articles of at least about 98% of theoretical density which is sufficient to provide the article with sufficient strength and fracture toughness for use in most structural applications such as gas turbine blades, cylinders, and other components of advanced heat engines.

Tiegs, Terry N. (Lenoir City, TN)

1987-01-01T23:59:59.000Z

296

Coors Ceramics Company,  

Office of Legacy Management (LM)

,' ,' Coors Ceramics Company, _' 600 Ninth Street ,# Golden. Colorado 80401 ' ., February 1, 1995 ,,/. Mr. James W. Wagoner II, Director 8. \ Off-SitelSavannah River Program Division i Office of Eastern Area Programs : Office of Environmental Restoration ., Department of Energy Washington, D.C.. 20585 Dear Mr. Wagoner: ' , : -, ' .' In discussionswith Mr. Marvin Kay, Mayor of the City of Golden, it is appropriate that I respond to yourtetter to him of January 24, 1995. Thank you for the information.sent with your letter. It appears it is supportive of our actions to decontaminate and demolish the building.(Building t6) ,used for the/handling of uranium under thecontract with the Atomic.Energy,Commission (AEC) during the 1960' s. ., - , I understand that ,no further action is,to be taken by DOE under the Formerly

297

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect

In the present quarter, oxygen transport perovskite ceramic membranes are evaluated for strength and fracture in oxygen gradient conditions. Oxygen gradients are created in tubular membranes by insulating the inner surface from the reducing environment by platinum foils. Fracture in these test conditions is observed to have a gradient in trans and inter-granular fracture as opposed to pure trans-granular fracture observed in homogeneous conditions. Fracture gradients are reasoned to be due to oxygen gradient set up in the membrane, variation in stoichiometry across the thickness and due to varying decomposition of the parent perovskite. The studies are useful in predicting fracture criterion in actual reactor conditions and in understanding the initial evolution of fracture processes.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2002-07-01T23:59:59.000Z

298

Ceramics for fusion devices  

SciTech Connect

Ceramics are required for a number of applications in fusion devices, among the most critical of which are magnetic coil insulators, windows for RF heating systems, and structural uses. Radiation effects dominate consideration of candidate materials, although good pre-irradiation properties are a requisite. Materials and components can be optimized by careful control of chemical and microstructural content, and application of brittle material design and testing techniques. Future directions for research and development should include further extension of the data base in the areas of electrical, structural, and thermal properties; establishment of a fission neutron/fusion neutron correlation including transmutation gas effects; and development of new materials tailored to meet the specific needs of fusion reactors.

Clinard, F.W. Jr.

1984-01-01T23:59:59.000Z

299

Ceramic Cerami Turbine Nozzle  

DOE Patents (OSTI)

A turbine nozzle vane assembly having a preestablished rate of thermal expansion is positioned in a gas turbine engine and being attached to conventional metallic components. The metallic components having a preestablished rate of thermal expansion being greater than the preestablished rate of thermal expansion of the turbine nozzle vane assembly. The turbine nozzle vane assembly includes an outer shroud and an inner shroud having a plurality of horizontally segmented vanes therebetween being positioned by a connecting member positioning segmented vanes in functional relationship one to another. The turbine nozzle vane assembly provides an economical, reliable and effective ceramic component having a preestablished rate of thermal expansion being greater than the preestablished rate of thermal expansion of the other component.

Boyd, Gary L. (Alpine, CA)

1997-04-01T23:59:59.000Z

300

Ceramic turbine nozzle  

DOE Patents (OSTI)

A turbine nozzle and shroud assembly having a preestablished rate of thermal expansion is positioned in a gas turbine engine and being attached to conventional metallic components. The metallic components have a preestablished rate of thermal expansion greater than the preestablished rate of thermal expansion of the turbine nozzle vane assembly. The turbine nozzle vane assembly includes a plurality of segmented vane defining a first vane segment and a second vane segment, each of the first and second vane segments having a vertical portion, and each of the first vane segments and the second vane segments being positioned in functional relationship one to another within a recess formed within an outer shroud and an inner shroud. The turbine nozzle and shroud assembly provides an economical, reliable and effective ceramic component having a preestablished rate of thermal expansion being less than the preestablished rate of thermal expansion of the other component. 4 figs.

Shaffer, J.E.; Norton, P.F.

1996-12-17T23:59:59.000Z

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

Ceramic turbine nozzle  

DOE Patents (OSTI)

A turbine nozzle and shroud assembly having a preestablished rate of thermal expansion is positioned in a gas turbine engine and being attached to conventional metallic components. The metallic components having a preestablished rate of thermal expansion being greater than the preestablished rate of thermal expansion of the turbine nozzle vane assembly. The turbine nozzle vane assembly includes a plurality of segmented vane defining a first vane segment and a second vane segment. Each of the first and second vane segments having a vertical portion. Each of the first vane segments and the second vane segments being positioned in functional relationship one to another within a recess formed within an outer shroud and an inner shroud. The turbine nozzle and shroud assembly provides an economical, reliable and effective ceramic component having a preestablished rate of thermal expansion being less than the preestablished rate of thermal expansion of the other component.

Shaffer, James E. (Maitland, FL); Norton, Paul F. (San Diego, CA)

1996-01-01T23:59:59.000Z

302

Polymers, Fractals, and Ceramic Materials  

Science Journals Connector (OSTI)

...application primarily as optical coatings and aerogels. Aerogels (1...4) Gelation //Polymer x Coating_rn Film Monomer Aggregation...Sintering.......... Aerogel Monolith Fig. 1. Ceramic...desired for index-matched coatings, then base-catalyzed materials...

DALE W. SCHAEFER

1989-02-24T23:59:59.000Z

303

Electroerosion resistance and structural phase transformations in electrospark and laser deposition of titanium alloys using composite ceramics based on ZrB2-ZrSi2 and TiN-Cr3C2 systems  

Science Journals Connector (OSTI)

The paper examines the mass transfer kinetics, structure, phase and chemical compositions, and micromechanical properties of electrospark and laser coatings on titanium alloys (including...2-ZrSi2 and TiN-Cr3C2 s...

I. A. Podchernyaeva; A. D. Panasyuk…

2008-01-01T23:59:59.000Z

304

Silicon carbide whisker reinforced 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 to 1950/sup 0/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, G.C.

1984-02-09T23:59:59.000Z

305

Fabrication of 316-L stainless steel and composite micro machine components using softlithography and powder metallurgy process.  

E-Print Network (OSTI)

??This thesis presents a new approach to fabricate high precision micro machine components from stainless steel and stainless steel ceramic composite materials, using Softlithography and… (more)

Imbaby, Mohamed

2010-01-01T23:59:59.000Z

306

Extruded ceramic honeycomb and method  

DOE Patents (OSTI)

Extruded low-expansion ceramic honeycombs comprising beta-spodumene solid solution as the principal crystal phase and with less than 7 weight percent of included mullite are produced by compounding an extrusion batch comprising a lithium aluminosilicate glass powder and a clay additive, extruding a green honeycomb body from the batch, and drying and firing the green extruded cellular honeycomb to crystallize the glass and clay into a low-expansion spodumene ceramic honeycomb body.

Day, J. Paul (Big Flats, NY)

1995-04-04T23:59:59.000Z

307

Metal-ceramic joint assembly  

DOE Patents (OSTI)

A metal-ceramic joint assembly in which a brazing alloy is situated between metallic and ceramic members. The metallic member is either an aluminum-containing stainless steel, a high chromium-content ferritic stainless steel or an iron nickel alloy with a corrosion protection coating. The brazing alloy, in turn, is either an Au-based or Ni-based alloy with a brazing temperature in the range of 9500 to 1200.degree. C.

Li, Jian (New Milford, CT)

2002-01-01T23:59:59.000Z

308

Advanced Research  

NLE Websites -- All DOE Office Websites (Extended Search)

Super HigH-TemperaTure alloyS and Super HigH-TemperaTure alloyS and CompoSiTeS From nb-W-Cr SySTemS Description The U.S. Department of Energy's Office of Fossil Energy (DOE-FE) has awarded a three-year grant to the University of Texas at El Paso (UTEP) and Argonne National Laboratory (ANL) to jointly explore the high-temperature properties of alloys composed of niobium (Nb), tungsten (W), and chromium (Cr). The grant is administered by the Advanced Research (AR) program of the National

309

Wedge edge ceramic combustor tile  

DOE Patents (OSTI)

A multipiece combustor has a portion thereof being made of a plurality of ceramic segments. Each of the plurality of ceramic segments have an outer surface and an inner surface. Each of the plurality of ceramic segments have a generally cylindrical configuration and including a plurality of joints. The joints define joint portions, a first portion defining a surface being skewed to the outer surface and the inner surface. The joint portions have a second portion defining a surface being skewed to the outer surface and the inner surface. The joint portions further include a shoulder formed intermediate the first portion and the second portion. The joints provide a sealing interlocking joint between corresponding ones of the plurality of ceramic segments. Thus, the multipiece combustor having the plurality of ceramic segment with the plurality of joints reduces the physical size of the individual components and the degradation of the surface of the ceramic components in a tensile stress zone is generally eliminated reducing the possibility of catastrophic failures.

Shaffer, James E. (Maitland, FL); Holsapple, Allan C. (Poway, CA)

1997-01-01T23:59:59.000Z

310

Wedge edge ceramic combustor tile  

DOE Patents (OSTI)

A multipiece combustor has a portion thereof being made of a plurality of ceramic segments. Each of the plurality of ceramic segments have an outer surface and an inner surface. Each of the plurality of ceramic segments have a generally cylindrical configuration and including a plurality of joints. The joints define joint portions, a first portion defining a surface being skewed to the outer surface and the inner surface. The joint portions have a second portion defining a surface being skewed to the outer surface and the inner surface. The joint portions further include a shoulder formed intermediate the first portion and the second portion. The joints provide a sealing interlocking joint between corresponding ones of the plurality of ceramic segments. Thus, the multipiece combustor having the plurality of ceramic segment with the plurality of joints reduces the physical size of the individual components and the degradation of the surface of the ceramic components in a tensile stress zone is generally eliminated reducing the possibility of catastrophic failures. 7 figs.

Shaffer, J.E.; Holsapple, A.C.

1997-06-10T23:59:59.000Z

311

Advanced Turbine Technology Applications Project (ATTAP). Annual report 1992  

SciTech Connect

This report summarizes work performed by Garrett Auxiliary Power Division (GAPD), a unit of Allied-Signal Aerospace Company, during calendar year 1992, toward development and demonstration of structural ceramic technology for automotive gas turbine engines. This work was performed for the US Department of Energy (DOE) under National Aeronautics and Space Administration (NASA) Contract DEN3-335, Advanced Turbine Technology Applications Project (ATTAP). GAPD utilized the AGT101 regenerated gas turbine engine developed under the previous DOE/NASA Advanced Gas Turbine (AGT) program as the ATTAP test bed for ceramic engine technology demonstration. ATTAP focussed on improving AGT101 test bed reliability, development of ceramic design methodologies, and improvement of fabrication and materials processing technology by domestic US ceramics fabricators. A series of durability tests was conducted to verify technology advancements. This is the fifth in a series of technical summary reports published annually over the course of the five-year contract.

Not Available

1993-03-01T23:59:59.000Z

312

Assessment of geometrical and transport properties of a fibrous C/C composite preform as  

E-Print Network (OSTI)

of carbon or ceramic fibres (SiC, Al2O3...) linked together by a carbon or ceramic matrix. The association1 Assessment of geometrical and transport properties of a fibrous C/C composite preform. Vignoles°*, Olivia Coindreau°, Azita Ahmadi$ , Dominique Bernard# ° Laboratoire des Composites Thermo

Boyer, Edmond

313

Invited Paper Shape Control of Composite Material Plates Using Piezoelectric Actuators  

E-Print Network (OSTI)

of smart structures. These material include piezoelectric polymers and ceramics, shape memory alloysInvited Paper Shape Control of Composite Material Plates Using Piezoelectric Actuators Brij N control of composite material plates using piezoelectric actuators. A finite element formulation

314

Ordered ceramic membranes  

SciTech Connect

Ceramic membranes have been formed from colloidal sols coated on porous clay supports. These supported membranes have been characterized in terms of their permeabilities and permselectivities to various aqueous test solutions. The thermal stabilities and pore structures of these membranes have been characterized by preparing unsupported membranes of the correpsonding material and performing N{sub 2} adsorption-desorption and X-ray diffraction studies on these membranes. To date, membranes have been prepared from a variety of oxides, including TiO{sub 2}, SiO{sub 2}, ZrO{sub 2}, and Al{sub 2}O{sub 3}, as well as Zr-, Fe-, and Nb-doped TiO{sub 2}. In many of these membranes pore diameters are less than 2 nm, while in others the pore diameters are between 3 and 5 nm. Procedures for fabricating porous clay supports with reproducible permeabilities for pure water are also discussed. 30 refs., 59 figs., 22 tabs.

Anderson, M.A.; Hill, C.G. Jr.; Zeltner, W.A.

1991-10-01T23:59:59.000Z

315

Ceramic HEPA Filter Program  

SciTech Connect

Potential benefits of ceramic filters in nuclear facilities: (1) Short term benefit for DOE, NRC, and industry - (a) CalPoly HTTU provides unique testing capability to answer questions for DOE - High temperature testing of materials, components, filter, (b) Several DNFSB correspondences and presentations by DNFSB members have highlighted the need for HEPA filter R and D - DNFSB Recommendation 2009-2 highlighted a nuclear facility response to an evaluation basis earthquake followed by a fire (aka shake-n-bake) and CalPoly has capability for a shake-n-bake test; (2) Intermediate term benefit for DOE and industry - (a) Filtration for specialty applications, e.g., explosive applications at Nevada, (b) Spin-off technologies applicable to other commercial industries; and (3) Long term benefit for DOE, NRC, and industry - (a) Across industry, strong desire for better performance filter, (b) Engineering solution to safety problem will improve facility safety and decrease dependence on associated support systems, (c) Large potential life-cycle cost savings, and (d) Facilitates development and deployment of LLNL process innovations to allow continuous ventilation system operation during a fire.

Mitchell, M A; Bergman, W; Haslam, J; Brown, E P; Sawyer, S; Beaulieu, R; Althouse, P; Meike, A

2012-04-30T23:59:59.000Z

316

HIGH-DENSITY CONCRETE WITH CERAMIC AGGREGATE BASED ON DEPLETED URANIUM DIOXIDE  

NLE Websites -- All DOE Office Websites (Extended Search)

DENSITY CONCRETE WITH CERAMIC AGGREGATE BASED ON DEPLETED URANIUM DENSITY CONCRETE WITH CERAMIC AGGREGATE BASED ON DEPLETED URANIUM DIOXIDE S.G. Ermichev, V.I. Shapovalov, N.V.Sviridov (RFNC-VNIIEF, Sarov, Russia) V.K. Orlov, V.M. Sergeev, A. G. Semyenov, A.M. Visik, A.A. Maslov, A. V. Demin, D.D. Petrov, V.V. Noskov, V. I. Sorokin, O. I. Uferov (VNIINM, Moscow, Russia) L. Dole (ORNL, Oak Ridge, USA) Abstract - Russia is researching the production and testing of concretes with ceramic aggregate based on depleted uranium dioxide (UO 2 ). These DU concretes are to be used as structural and radiation-shielded material for casks for A-plant spent nuclear fuel transportation and storage. This paper presents the results of studies aimed at selection of ceramics and concrete composition, justification of their production technology, investigation of mechanical properties, and chemical stability.

317

Carbon nanotube composites P. J. F. Harris*  

E-Print Network (OSTI)

Carbon nanotube composites P. J. F. Harris* Carbon nanotubes are molecular-scale tubes of graphitic. There is currently great interest in exploiting these properties by incorporating carbon nanotubes into some form/ceramic and nanotube/metal composites. This review outlines the properties of carbon nanotubes and describes

Harris, Peter J F

318

Ceramic oxyanion emitter  

DOE Patents (OSTI)

A rare earth oxide matrix (composition of matter) is formed which emits (upon heating) heavy metal oxide anions (oxyanions) into a gas phase, wherein the anions are emitted with high intensity, and wherein longevity of life of the composition of matter is retained. The matter is formed by blending a major component of a rare earth oxide, europium oxide (Eu{sub 2}O{sub 3}) or ytterbium oxide (Yb{sub 2}O{sub 3}), with a minor component of a barium (Ba), calcium (Ca) or strontium (Sr) salt of a heavy metal oxyanion. Heavy anions are emitted upon heating the composition of matter to a predetermined temperature of about 800 C.

Delmore, J.E.; Appelhans, A.D.; Peterson, E.S.

1996-04-09T23:59:59.000Z

319

Surface micromachining of unfired ceramic sheets  

E-Print Network (OSTI)

the un?red ceramic sample during thermal processing steps.ceramic samples were af?xed to 4 00 silicon ‘‘handle’’ wafers using the following bonding agents: thermal

Rheaume, Jonathan M.; Pisano, Albert P.

2011-01-01T23:59:59.000Z

320

Ceramic Fuel Cells (SOFC) | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Ceramic Fuel Cells (SOFC) Ceramic Fuel Cells (SOFC) Presented at the NREL Hydrogen and Fuel Cell Manufacturing R&D Workshop in Washington, DC, August 11-12, 2011....

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

Crystalline Ceramic Waste Forms: Report Detailing Data Collection In Support Of Potential FY13 Pilot Scale Melter Test  

SciTech Connect

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 successfully produced from a melting and crystallization process. The objective of this report is to summarize the data collection in support of future melter demonstration testing for crystalline ceramic waste forms. The waste stream used as the basis for the development and testing is 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. The principal difficulties encountered during processing of the ?reference ceramic? waste form by a melt and crystallization process were the incomplete incorporation of Cs into the hollandite phase and the presence of secondary Cs-Mo non-durable phases. In the single phase hollandite system, these issues were addressed in this study by refining the compositions to include Cr as a transition metal element and the use of Ti/TiO{sub 2} buffer to maintain reducing conditions. Initial viscosity studies of ceramic waste forms indicated that the pour spout must be maintained above 1400{deg}C to avoid flow blockages due to crystallization. In-situ electron irradiations simulate radiolysis effects indicated hollandite undergoes a crystalline to amorphous transition after a radiation dose of 10{sup 13} Gy which corresponds to approximately 1000 years at anticipated doses (2?10{sup 10}-2?10{sup 11} Gy). Dual-beam ion irradiations employing light ion beam (such as 5 MeV alpha) and heavy ion beam (such as 100 keV Kr) studies indicate that reference ceramic waste forms are radiation tolerant to the ??particles and ?-particles, but are susceptible to a crystalline to amorphous transition under recoil nuclei effects. A path forward for refining the processing steps needed to form the targeted phase assemblages is outlined in this report. Processing modifications including melting in a reducing atmosphere with the use of Ti/TiO2 buffers, and the addition of Cr to the transition metal additives to facilitate Cs-incorporation in the hollandite phase. In addition to melt processing, alternative fabrication routes are being considered including Spark Plasma Sintering (SPS) and Hot Isostatic Pressing (HIP).

Brinkman, K. S.; Amoroso, J.; Marra, J. C.; Fox, K. M.

2012-09-21T23:59:59.000Z

322

Hydridosiloxanes as precursors to ceramic products  

DOE Patents (OSTI)

A method is provided for preparing ceramic precursors from hydridosiloxane starting materials and then pyrolyzing these precursors to give rise to silicious ceramic materials. Si--H bonds present in the hydridosiloxane starting materials are catalytically activated, and the activated hydrogen atoms may then be replaced with nonhydrogen substituents. These preceramic materials are pyrolyzed in a selected atmosphere to give the desired ceramic product. Ceramic products which may be prepared by this technique include silica, silicon oxynitride, silicon carbide, metal silicates, and mullite.

Blum, Yigal D. (San Jose, CA); Johnson, Sylvia M. (Piedmont, CA); Gusman, Michael I. (Palo Alto, CA)

1997-01-01T23:59:59.000Z

323

Hydridosiloxanes as precursors to ceramic products  

DOE Patents (OSTI)

A method is provided for preparing ceramic precursors from hydridosiloxane starting materials and then pyrolyzing these precursors to give rise to silicious ceramic materials. Si-H bonds present in the hydridosiloxane starting materials are catalytically activated, and the activated hydrogen atoms may then be replaced with nonhydrogen substituents. These preceramic materials are pyrolyzed in a selected atmosphere to give the desired ceramic product. Ceramic products which may be prepared by this technique include silica, silicon oxynitride, silicon carbide, metal silicates, and mullite.

Blum, Y.D.; Johnson, S.M.; Gusman, M.I.

1997-06-03T23:59:59.000Z

324

Ceramic Thin Films: Fabrication and Applications  

Science Journals Connector (OSTI)

...SPRAYED CERAMIC COATING, JOURNAL...PB1-XCAXTIO3 THIN-FILM GROWN BY...ELECTRICAL, OPTICAL, AND ELECTRO-OPTIC...fabrication and applications. | Ceramics...controlled optical switches...Ceramic coatings ofalumina...modified by the application of mechanical...material as a thin film cannot only...successive coatings. Although...respect to CVD that the...purposes. Applications of Thin Film Ceramics...

M. Sayer; K. Sreenivas

1990-03-02T23:59:59.000Z

325

Private-Public Partnerships for U.S. Advanced Manufacturing  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Polymer Composite Manufacturing Workshop Crystal City January 13, 2014 Private-Public Partnerships for U.S. Advanced Manufacturing Dr. Frank W. Gayle Advanced Manufacturing...

326

Engineering Development of Ceramic Membrane Reactor  

E-Print Network (OSTI)

ceramic Ion Transport Membrane (ITM) reactor system for low-cost conversion of natural gas to hydrogen;7 A Revolutionary Technology Using Ceramic Membranes Ion Transport Membranes (ITM) ­ Non-porous multiEngineering Development of Ceramic Membrane Reactor Systems for Converting Natural Gas to Hydrogen

327

Process for making ceramic insulation  

DOE Patents (OSTI)

A method is provided for producing insulation materials and insulation for high temperature applications using novel castable and powder-based ceramics. The ceramic components produced using the proposed process offers (i) a fine porosity (from nano-to micro scale); (ii) a superior strength-to-weight ratio; and (iii) flexibility in designing multilayered features offering multifunctionality which will increase the service lifetime of insulation and refractory components used in the solid oxide fuel cell, direct carbon fuel cell, furnace, metal melting, glass, chemical, paper/pulp, automobile, industrial heating, coal, and power generation industries. Further, the ceramic components made using this method may have net-shape and/or net-size advantages with minimum post machining requirements.

Akash, Akash (Salt Lake City, UT); Balakrishnan, G. Nair (Sandy, UT)

2009-12-08T23:59:59.000Z

328

Superplastic forging nitride ceramics  

DOE Patents (OSTI)

A process is disclosed for preparing silicon nitride ceramic parts which are relatively flaw free and which need little or no machining, said process comprising the steps of: (a) preparing a starting powder by wet or dry mixing ingredients comprising by weight from about 70% to about 99% silicon nitride, from about 1% to about 30% of liquid phase forming additive and from 1% to about 7% free silicon; (b) cold pressing to obtain a preform of green density ranging from about 30% to about 75% of theoretical density; (c) sintering at atmospheric pressure in a nitrogen atmosphere at a temperature ranging from about 1,400 C to about 2,200 C to obtain a density which ranges from about 50% to about 100% of theoretical density and which is higher than said preform green density, and (d) press forging workpiece resulting from step (c) by isothermally uniaxially pressing said workpiece in an open die without initial contact between said workpiece and die wall perpendicular to the direction of pressing and so that pressed workpiece does not contact die wall perpendicular to the direction of pressing, to substantially final shape in a nitrogen atmosphere utilizing a temperature within the range of from about 1,400 C to essentially 1,750 C and strain rate within the range of about 10[sup [minus]7] to about 10[sup [minus]1] seconds[sup [minus]1], the temperature and strain rate being such that surface cracks do not occur, said pressing being carried out to obtain a shear deformation greater than 30% whereby superplastic forging is effected.

Panda, P.C.; Seydel, E.R.; Raj, R.

1988-03-22T23:59:59.000Z

329

Lead-free piezoelectric ceramics with composition of (0.97?x)Na1/2Bi1/2TiO3-0.03NaNbO3-xBaTiO3  

Science Journals Connector (OSTI)

Compositions in (Na1/2Bi1/2)TiO3 based ternary system, (0.97 ? x) (Na1/2Bi1/2)TiO3-0.03NaNbO3-xBaTiO3 (x = 0, 0.01, 0.02, 0.04, 0.05, 0.06, 0.08) are synthesized using conventional solid state reaction method. In...

Yugong Wu; Huili Zhang; Yue Zhang; Jinyi Ma; Daohua Xie

330

Heat exchanger with ceramic elements  

DOE Patents (OSTI)

An annular heat exchanger assembly includes a plurality of low thermal growth ceramic heat exchange members with inlet and exit flow ports on distinct faces. A mounting member locates each ceramic member in a near-annular array and seals the flow ports on the distinct faces into the separate flow paths of the heat exchanger. The mounting member adjusts for the temperature gradient in the assembly and the different coefficients of thermal expansion of the members of the assembly during all operating temperatures.

Corey, John A. (North Troy, NY)

1986-01-01T23:59:59.000Z

331

Grained composite materials prepared by combustion synthesis under mechanical pressure  

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

332

Electromagnetic Isolation Solutions in Low Temperature Cofired Ceramic (LTCC)  

SciTech Connect

Low Temperature Cofired Ceramic (LTCC) is a commercial ceramic-glass multilayer technology with compelling advantages for microelectronics, microsystems and sensors. High frequency applications require good electrical properties such as low dielectric loss and newer applications require extreme isolation from electromagnetic interference (EMI) that is even difficult to measure (-150db). Approaches to providing this isolation, once provided by via fences, have included sidewall coating and full tape thickness features (FTTF) that have been introduced by the filling of slots with via-fill compositions. Several techniques for creating these structures have been modeled for stress and temperature effects in the face of other necessary attachments, such as metallic seal frames. The relative effects of attachment media, FTTF geometry, and alternative measures will be reported. Approaches for thick film and thin film implementations are described.

Krueger, Daniel; Peterson, Ken; Euler, Laurie

2011-10-09T23:59:59.000Z

333

Oxygen Transport Ceramic Membranes  

SciTech Connect

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and initial studies on newer composition of Ti doped LSF. Dense OTM bars provided by Praxair were loaded to fracture at varying stress rates. Studies were done at room temperature in air and at 1000 C in a specified environment to evaluate slow crack growth behavior. In addition, studies were also begun to obtain reliable estimates of fracture toughness and stable crack growth in specific environments. Newer composition of Ti doped LSF membranes were characterized by neutron diffraction analysis. Quench studies indicated an apparent correlation between the unit cell volume and oxygen occupancy. The studies however, indicated an anomaly of increasing Fe/Ti ratio with change in heat treatment. Ti doped LSF was also characterized for stoichiometry as a function of temp and pO{sub 2}. The non stoichiometry parameter {delta} was observed to increase almost linearly on lowering pO{sub 2} until a ideal stoichiometric composition of {delta} = 0.175 was approached.

S. Bandopadhyay; N. Nagabhushana; X.-D Zhou; W.B. Yelon; H.U. Anderson; Alan Jacobson; C.A. Mims

2004-02-01T23:59:59.000Z

334

Evaluation of silicon-nitride ceramic valves.  

SciTech Connect

Silicon-nitride ceramic valves can improve the performance of both light- and heavy-duty automotive engines because of the superior material properties of silicon nitrides over current metal alloys. However, ceramics are brittle materials that may introduce uncertainties in the reliability and durability of ceramic valves. As a result, the lifetime of ceramic valves are difficult to predict theoretically due to wide variations in the type and distribution of microstructural flaws in the material. Nondestructive evaluation (NDE) methods are therefore required to assess the quality and reliability of these valves. Because ceramic materials are optically translucent and the strength-limiting flaws are normally located near the valve surface, a laser-scatter method can be used for NDE evaluation of ceramic valves. This paper reviews the progress in the development of this NDE method and its application to inspect silicon-nitride ceramic valves at various stages of manufacturing and bench and engine tests.

Sun, J. G.; Zhang, J. M.; Andrews, M. J.; Tretheway, J. S.; Phillips, N. S .L.; Jensen, J. A.; Nuclear Engineering Division; Univ. of Texas; Caterpillar, Inc.

2008-01-01T23:59:59.000Z

335

Dispersion toughened silicon carbon ceramics  

DOE Patents (OSTI)

Fracture resistant silicon carbide ceramics are provided by incorporating therein a particulate dispersoid selected from the group consisting of (a) a mixture of boron, carbon and tungsten, (b) a mixture of boron, carbon and molybdenum, (c) a mixture of boron, carbon and titanium carbide, (d) a mixture of aluminum oxide and zirconium oxide, and (e) boron nitride. 4 figures.

Wei, G.C.

1984-01-01T23:59:59.000Z

336

Gas Separations using Ceramic Membranes  

SciTech Connect

This project has been oriented toward the development of a commercially viable ceramic membrane for high temperature gas separations. A technically and commercially viable high temperature gas separation membrane and process has been developed under this project. The lab and field tests have demonstrated the operational stability, both performance and material, of the gas separation thin film, deposited upon the ceramic membrane developed. This performance reliability is built upon the ceramic membrane developed under this project as a substrate for elevated temperature operation. A comprehensive product development approach has been taken to produce an economically viable ceramic substrate, gas selective thin film and the module required to house the innovative membranes for the elevated temperature operation. Field tests have been performed to demonstrate the technical and commercial viability for (i) energy and water recovery from boiler flue gases, and (ii) hydrogen recovery from refinery waste streams using the membrane/module product developed under this project. Active commercializations effort teaming with key industrial OEMs and end users is currently underway for these applications. In addition, the gas separation membrane developed under this project has demonstrated its economical viability for the CO2 removal from subquality natural gas and landfill gas, although performance stability at the elevated temperature remains to be confirmed in the field.

Paul KT Liu

2005-01-13T23:59:59.000Z

337

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

E-Print Network (OSTI)

and elasticity in multiphase materials is emphasized. The results for the constriction resistance are comparedThermal resistance of bridged cracks in fiber-reinforced ceramic composites John Dryden Department of Mechanical and Materials Engineering, The University of Western Ontario, London, Ontario, Canada, N6A 5B9

Zok, Frank

338

Plasma-Induced Erosion on Ceramic Wall Structures in Hall-Effect Thrusters  

E-Print Network (OSTI)

Plasma-Induced Erosion on Ceramic Wall Structures in Hall-Effect Thrusters Thomas Burton University) hot-pressed composite, denoted as M26, was used as the insulating chamber wall for a xenon plasma Hall expansion of BN in the amorphous silica matrix. Exfoliation accompanied the microcracking in BN and resulted

Walker, Mitchell

339

Nanostructured composite reinforced material  

DOE Patents (OSTI)

A family of materials wherein nanostructures and/or nanotubes are incorporated into a multi-component material arrangement, such as a metallic or ceramic alloy or composite/aggregate, producing a new material or metallic/ceramic alloy. The new material has significantly increased strength, up to several thousands of times normal and perhaps substantially more, as well as significantly decreased weight. The new materials may be manufactured into a component where the nanostructure or nanostructure reinforcement is incorporated into the bulk and/or matrix material, or as a coating where the nanostructure or nanostructure reinforcement is incorporated into the coating or surface of a "normal" substrate material. The nanostructures are incorporated into the material structure either randomly or aligned, within grains, or along or across grain boundaries.

Seals, Roland D. (Oak Ridge, TN); Ripley, Edward B. (Knoxville, TN); Ludtka, Gerard M. (Oak Ridge, TN)

2012-07-31T23:59:59.000Z

340

Carbonate-salt-based composite materials for medium- and high-temperature thermal energy storage  

Science Journals Connector (OSTI)

Abstract This paper discusses composite materials based on inorganic salts for medium- and high-temperature thermal energy storage application. The composites consist of a phase change material (PCM), a ceramic material, and a high thermal conductivity material. The ceramic material forms a microstructural skeleton for encapsulation of the PCM and structural stability of the composites; the high thermal conductivity material enhances the overall thermal conductivity of the composites. Using a eutectic salt of lithium and sodium carbonates as the PCM, magnesium oxide as the ceramic skeleton, and either graphite flakes or carbon nanotubes as the thermal conductivity enhancer, we produced composites with good physical and chemical stability and high thermal conductivity. We found that the wettability of the molten salt on the ceramic and carbon materials significantly affects the microstructure of the composites.

Zhiwei Ge; Feng Ye; Hui Cao; Guanghui Leng; Yue Qin; Yulong Ding

2014-01-01T23:59:59.000Z

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.


341

Oxygen Transport Ceramic Membranes  

SciTech Connect

In this quarter a systematic analysis on the decomposition behavior of the OTM membranes at air and nitrogen were initiated to understand the structural and stoichiometric changes associated with elevated temperatures. Evaluation of the flexural strengths using 4-point bend test was also started for the dual phase membranes. Initial results on the synthesis of dual phase composite materials have been obtained. The measurements have focused on the compatibility of mixed conductors with the pure ionic conductors yttria stabilized zirconia (YSZ) and gadolinium doped ceria (GDC). The initial results obtained for three different mixed conductors suggest that (GDC) is the better choice. A new membrane permeation system has been designed and tested and sintering studies of biphasic systems are in progress.

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

2006-05-01T23:59:59.000Z

342

Oxygen Transport Ceramic Membranes  

SciTech Connect

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 current research, the electrical conductivity and Seebeck coefficient were measured as a function of temperature in air. Based on these measurements, the charge carrier concentration, net acceptor dopant concentration, activation energy of conduction and mobility were estimated. The studies on the fracture toughness of the LSFT and dual phase membranes at room temperature have been completed and reported previously. The membranes that are exposed to high temperatures at an inert and a reactive atmosphere undergo many structural and chemical changes which affects the mechanical properties. To study the effect of temperature on the membranes when exposed to an inert environment, the membranes (LAFT and Dual phase) were heat treated at 1000 C in air and N{sub 2} atmosphere and hardness and fracture toughness of the membranes were studied after the treatment. The indentation method was used to find the fracture toughness and the effect of the heat treatment on the mechanical properties of the membranes. Further results on the investigation of the origin of the slow kinetics on reduction of ferrites have been obtained. The slow kinetics appears 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. 2-D modeling of oxygen movement has been undertaken in order to fit isotope data. The model will serve to study ''frozen'' profiles in patterned or composite membranes.

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

2005-11-01T23:59:59.000Z

343

Oxygen Transport Ceramic Membranes  

SciTech Connect

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. The in situ electrical conductivity and Seebeck coefficient measurements were made on LSFT at 1000 and 1200 C over the oxygen activity range from air to 10{sup -15} atm. The electrical conductivity measurements exhibited a p to n type transition at an oxygen activity of 1 x 10{sup -10} at 1000 C and 1 x 10{sup -6} at 1200 C. Thermogravimetric studies were also carried out over the same oxygen activities and temperatures. Based on the results of these measurements, the chemical and mechanical stability range of LSFT were determined and defect structure was established. The studies on the fracture toughness of the LSFT and dual phase membranes exposed to air and N{sub 2} at 1000 C was done and the XRD and SEM analysis of the specimens were carried out to understand the structural and microstructural changes. The membranes that are exposed to high temperatures at an inert and a reactive atmosphere undergo many structural and chemical changes which affect the mechanical properties. A complete transformation of fracture behavior was observed in the N{sub 2} treated LSFT samples. Further results to investigate 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. Recent results on transient kinetic data are presented. The 2-D modeling of oxygen movement has been undertaken in order to fit isotope data. The model is used to study ''frozen'' profiles in patterned or composite membranes.

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

2005-02-01T23:59:59.000Z

344

Method of preparing corrosion resistant composite materials  

DOE Patents (OSTI)

Method of manufacture of ceramic materials which require stability in severely-corrosive environment 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 surfide 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)

1993-01-01T23:59:59.000Z

345

SUPPORTED DENSE CERAMIC MEMBRANES FOR OXYGEN SEPARATION  

SciTech Connect

Mixed-conducting membranes have the ability to conduct oxygen with perfect selectivity at elevated temperatures, which makes them an extremely attractive alternative for oxygen separation and membrane reactor applications. The ability to reliably fabricate these membranes in thin or thick films would enable solid-state divisional limitations to be minimized, thus providing higher oxygen flux. Based on that motivation, the overall objective for this project is to develop and demonstrate a strategy for the fabrication of supported Wick film ceramic mixed conducting membranes, and improve the understanding of the fundamental issues associated with reliable fabrication of these membranes. The project has focused on the mixed-conducting ceramic composition SrCo{sub 0.5}FeO{sub x} because of its superior permeability and stability in reducing atmospheres. The fabrication strategy employed involves the deposition of SrCo{sub 0.5}FeO{sub x} thick films onto porous supports of the same composition. In the second year of this project, we completed characterization of the sintering and phase behavior of the porous SrCo{sub 0.5}FeO{sub x} supports, leading to a standard support fabrication methodology. Using a doctor blade method, pastes made from aerosol-derived SrCo{sub 0.5}FeO{sub x} powder dispersed with polyethylene glycol were applied to the supports, and the sintering behavior of the thick film membranes was examined in air and nitrogen atmospheres. It has been demonstrated that the desired crystalline phase content can be produced in the membranes, and that the material in the membrane layer can be highly densified without densifying the underlying support. However, considerable cracking and opening of the film occurred when films densified to a high extent. The addition of MgO into the SrCo{sub 0.5}FeO{sub x} supports was shown to inhibit support sintering so that temperatures up to 1300 C, where significant liquid formation occurs, could be used for film sintering. This successfully reduced cracking, however the films retained open porosity. The investigation of this concept will be continued in the final year of the project. Investigation of a metal organic chemical vapor deposition (MOCVD) method for defect mending in dense membranes was also initiated. An appropriate metal organic precursor (iron tetramethylheptanedionate) was identified whose deposition can be controlled by access to oxygen at temperatures in the 280-300 C range. Initial experiments have deposited iron oxide, but only on the membrane surface; thus refinement of this method will continue.

Timothy L. Ward

2000-06-30T23:59:59.000Z

346

An Innovative Ceramic Corrosion Protection System for Zircaloy Cladding  

SciTech Connect

Light Water reactor (LWR) fuel performance is currently limited by thermal, chemical and mechanical constraints associated with the design, fabrication, and operation of the fuel in incore operation. Corrosion of the zirconium based (Zircaloy-4) alloy cladding of the fuel is a primary limiting factor. Recent success at the University of Florida in developing thin ceramic films with great adhesive properties for metal substrates offers an innovative breakthrough for eliminating a major weakness of the Zircaloy clad. ?The University of Florida proposes to coat the existing Zircaloy clad tubes with a ceramic coating for corrosion protection. An added bonus of this approach would be the implementation of a boron-containing burnable poison outer layer will also be demonstrated as part of the ceramic coating development. In this proposed effort, emphasis will be on the ceramic coating with only demonstration of feasibility on the burnable outer coating approach. This proposed program i s expected to give a step change (approximately a doubling) in clad lifetime before failure due to corrosion. In the development of ceramic coatings for Zircaloy-4 clad, silicon carbide and zirconium carbide coatings will first be applied to Zircaloy-4 coupons and cladding samples by thermal assisted chemical vapor deposition, plasma assisted chemical vapor deposition or by laser ablation deposition. All of these processes are in use at the University of Florida and have shown great potential. The questions of adhesion and thermal expansion mismatch of the ceramic coating to the Zircaloy substrate will be addressed. Several solutions to these conditions will be examined, if needed. These solutions include the use of a zirconium oxide compliant layer, employment of a laser roughened surface and the use of a gradient composition interlayer. These solutions have already been shown to be effective for other high modulus coatings on metal substrates. Mechanical properties and adhesion of the coatings will be monitored as a function of the coating process parameters. The corrosion protection of the various coatings will be evaluated by accelerated corrosion testing. Engineering requirements for coating a full size Zircaloy clad tube will be determined. It is expected that the coating process will add approximately 10 dollars or 10% to the price of a tube. In the second approach, the University of Florida will demonstrate the feasibility to add a boron carbide outer layer to functions as a burnable poison.(B204)

Ronald H. Baney, Dr. D. Butt, Dr. P. Demkowicz, Dr. G. Fuchs Department of Materials Science; James S. Tulenko, Department of Nuclear and Radiological Engineering; University of Florida.

2003-02-19T23:59:59.000Z

347

Metal-to-ceramic attachment device  

SciTech Connect

A metal-to-ceramic fastening device is disclosed for securing a metal member to a ceramic member with respective confronting surfaces thereon clamped together, comprising a threaded bolt adapted to extend through a bolt hole in the metal member and into an aligned opening in the ceramic member, a rod nut threadedly receiving the bolt and adapted to span the opening in the ceramic member, and a pressure limiting member received on the bolt between the nut and the confronting surface of the metal member for limiting the movement of the nut toward the metal member when the bolt is tightened, so as to limit the pressure applied by the nut to the ceramic member to avoid damage thereto. The fastening device also prevents damage to the ceramic member due to thermal stresses. The pressure limiting member may have a shallow dish-shaped depression facing the rod nut to assist in accommodating thermal stresses.

Pavelka, Edwin A. (Bartlesville, OK); Grindstaff, Quirinus G. (Bartlesville, OK); Scheppele, Stuart E. (Bartlesville, OK)

1985-01-01T23:59:59.000Z

348

Oxygen Transport Ceramic Membranes  

SciTech Connect

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 this report, Moessbauer spectroscopy was used to study the local environmentals of LSFT with various level of oxygen deficiency. Ionic valence state, magnetic interaction and influence of Ti on superexchange are discussed Stable crack growth studies on Dense OTM bars provided by Praxair were done at elevated temperature, pressure and elevated conditions. Post-fracture X-ray data of the OTM fractured at 1000 C in environment were refined by FullProf code and results indicate a distortion of the parent cubic perovskite to orthorhombic structure with reduced symmetry. TGA-DTA studies on the post-fracture samples also indicated residual effect arising from the thermal and stress history of the samples. An electrochemical cell has been designed and built for measurements of the Seebeck coefficient as a function of temperature and pressure. The initial measurements on La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} are reported. Neutron diffraction measurements of the same composition are in agreement with both the stoichiometry and the kinetic behavior observed in coulometric titration measurements. 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 COCO{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; X.-D Zhou; Q. Cai; J. Yang; W.B. Yelon; W.J. James; H.U. Anderson; Alan Jacobson; C.A. Mims

2004-10-01T23:59:59.000Z

349

Advanced High Porosity Ceramic Honeycomb Wall Flow Filters  

Energy.gov (U.S. Department of Energy (DOE))

2007 Diesel Engine-Efficiency & Emissions Research Conference (DEER 2007). 13-16 August, 2007, Detroit, Michigan. Sponsored by the U.S. Department of Energy's (DOE) Office of FreedomCAR and Vehicle Technologies (OFCVT).

350

REQUEST BY KYOCERA INDUSTRIAL CERAMICS CORPORATION FOR AN ADVANCE...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

supplied only by foreign sources. KICC will manufacture W(A)-94-007 ORO-574 WAIVER ACTION ABSTRACT REQUESTOR CONTRACT SCOPE OF WORK RATIONALE FOR DECISION DISPOSITION Kyocera...

351

Particle-induced amorphization of complex ceramics. Final report  

SciTech Connect

The crystalline-to-amorphous (c-a) phase transition is of fundamental importance. Particle irradiations provide an important, highly controlled means of investigating this phase transformation and the structure of the amorphous state. The interaction of heavy-particles with ceramics is complex because these materials have a wide range of structure types, complex compositions, and because chemical bonding is variable. Radiation damage and annealing can produce diverse results, but most commonly, single crystals become aperiodic or break down into a polycrystalline aggregate. The authors continued the studies of the transition from the periodic-to-aperiodic state in natural materials that have been damaged by {alpha}-recoil nuclei in the uranium and thorium decay series and in synthetic, analogous structures. The transition from the periodic to aperiodic state was followed by detailed x-ray diffraction analysis, in-situ irradiation/transmission electron microscopy, high resolution transmission electron microscopy, extended x-ray absorption fine structure spectroscopy/x-ray absorption near edge spectroscopy and other spectroscopic techniques. These studies were completed in conjunction with bulk irradiations that can be completed at Los Alamos National Laboratory or Sandia National Laboratories. Principal questions addressed in this research program included: (1) What is the process at the atomic level by which a ceramic material is transformed into a disordered or aperiodic state? (2) What are the controlling effects of structural topology, bond-type, dose rate, and irradiation temperature on the final state of the irradiated material? (3) What is the structure of the damaged material? (4) What are the mechanisms and kinetics for the annealing of interstitial and aggregate defects in these irradiated ceramic materials? (5) What general criteria may be applied to the prediction of amorphization in complex ceramics?

Ewing, R.C.; Wang, L.M.

1998-08-01T23:59:59.000Z

352

Segmented ceramic liner for induction furnaces  

DOE Patents (OSTI)

A non-fibrous ceramic liner for induction furnaces is provided by vertically stackable ring-shaped liner segments made of ceramic material in a light-weight cellular form. The liner segments can each be fabricated as a single unit or from a plurality of arcuate segments joined together by an interlocking mechanism. Also, the liner segments can be formed of a single ceramic material or can be constructed of multiple concentric layers with the layers being of different ceramic materials and/or cellular forms. Thermomechanically damaged liner segments are selectively replaceable in the furnace. 5 figs.

Gorin, A.H.; Holcombe, C.E.

1994-07-26T23:59:59.000Z

353

MECHANICAL PROPERTIES OF POROUS PNZT POLYCRYSTALLINE CERAMICS  

E-Print Network (OSTI)

F. P. Knudsen, "Dependence of Mechanical Strength of BrittleMicrostruc- ture on the Mechanical Properties of Ceramics,"of Porosity on the Mechanical Properties of Lead Zirconate-

Biswas, D.R.

2010-01-01T23:59:59.000Z

354

Advanced Materials for Mercury 50 Gas Turbine Combustion System  

SciTech Connect

Solar Turbines Incorporated (Solar), under cooperative agreement number DE-FC26-0CH11049, has conducted development activities to improve the durability of the Mercury 50 combustion system to 30,000 hours life and reduced life cycle costs. This project is part of Advanced Materials in the Advanced Industrial Gas Turbines program in DOE's Office of Distributed Energy. The targeted development engine was the Mercury{trademark} 50 gas turbine, which was developed by Solar under the DOE Advanced Turbine Systems program (DOE contract number DE-FC21-95MC31173). As a generator set, the Mercury 50 is used for distributed power and combined heat and power generation and is designed to achieve 38.5% electrical efficiency, reduced cost of electricity, and single digit emissions. The original program goal was 20,000 hours life, however, this goal was increased to be consistent with Solar's standard 30,000 hour time before overhaul for production engines. Through changes to the combustor design to incorporate effusion cooling in the Generation 3 Mercury 50 engine, which resulted in a drop in the combustor wall temperature, the current standard thermal barrier coated liner was predicted to have 18,000 hours life. With the addition of the advanced materials technology being evaluated under this program, the combustor life is predicted to be over 30,000 hours. The ultimate goal of the program was to demonstrate a fully integrated Mercury 50 combustion system, modified with advanced materials technologies, at a host site for a minimum of 4,000 hours. Solar was the Prime Contractor on the program team, which includes participation of other gas turbine manufacturers, various advanced material and coating suppliers, nationally recognized test laboratories, and multiple industrial end-user field demonstration sites. The program focused on a dual path development route to define an optimum mix of technologies for the Mercury 50 and future gas turbine products. For liner and injector development, multiple concepts including high thermal resistance thermal barrier coatings (TBC), oxide dispersion strengthened (ODS) alloys, continuous fiber ceramic composites (CFCC), and monolithic ceramics were evaluated before down-selection to the most promising candidate materials for field evaluation. Preliminary, component and sub-scale testing was conducted to determine material properties and demonstrate proof-of-concept. Full-scale rig and engine testing was used to validated engine performance prior to field evaluation at a Qualcomm Inc. cogeneration site located in San Diego, California. To ensure that the CFCC liners with the EBC proposed under this program would meet the target life, field evaluations of ceramic matrix composite liners in Centaur{reg_sign} 50 gas turbine engines, which had previously been conducted under the DOE sponsored Ceramic Stationary Gas Turbine program (DE-AC02-92CE40960), was continued under this program at commercial end-user sites under Program Subtask 1A - Extended CFCC Materials Durability Testing. The goal of these field demonstrations was to demonstrate significant component life, with milestones of 20,000 and 30,000 hours. Solar personnel monitor the condition of the liners at the field demonstration sites through periodic borescope inspections and emissions measurements. This program was highly successful at evaluating advanced materials and down-selecting promising solutions for use in gas turbine combustions systems. The addition of the advanced materials technology has enabled the predicted life of the Mercury 50 combustion system to reach 30,000 hours, which is Solar's typical time before overhaul for production engines. In particular, a 40 mil thick advanced Thermal Barrier Coating (TBC) system was selected over various other TBC systems, ODS liners and CFCC liners for the 4,000-hour field evaluation under the program. This advanced TBC is now production bill-of-material at various thicknesses up to 40 mils for all of Solar's advanced backside-cooled combustor liners (Centaur 50, Taurus 60, Mars 100, Taurus 70,

Price, Jeffrey

2008-09-30T23:59:59.000Z

355

Proceedings of the AD HOC Workshop on Ceramics for Li/FeS{sub 2} batteries  

SciTech Connect

Representatives from industry, the U.S. Advanced Battery Consortium (USABC), DOE, national laboratories, and other govt agencies met to develop recommendations and actions for accelerating the development of ceramic components critical to the successful introduction of the Li/FeS{sub 2} bipolar battery for electric vehicles. Most of the workshop is devoted to electrode materials, bipolar designs, separators, and bipolar plates. The bulk of this document is viewographs and is divided into: ceramics, USABC overview, SAFT`s Li/FeS{sub 2} USABC program, bipolar Li/FeS{sub 2} component development, design requirements for bipolar plates, separator design requirements, compatibility of ceramic insulators with lithium, characterization of MgO for use in separators, resistivity measurements of separators, sintered AlN separators for LiMS batteries, etc.

Not Available

1993-12-31T23:59:59.000Z

356

Cold Crucible Induction Melter Studies for Making Glass Ceramic...  

NLE Websites -- All DOE Office Websites (Extended Search)

Cold Crucible Induction Melter Studies for Making Glass Ceramic Waste Forms: A Feasibility Assessment. Cold Crucible Induction Melter Studies for Making Glass Ceramic Waste Forms:...

357

Development of Steel Fastener Nano-Ceramic Coatings for Corrosion...  

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

Steel Fastener Nano-Ceramic Coatings for Corrosion Protection of Magnesium Parts (AMD-704) Development of Steel Fastener Nano-Ceramic Coatings for Corrosion Protection of Magnesium...

358

Oxygen Transport Ceramic Membranes  

SciTech Connect

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 this report, in situ neutron diffraction was used to characterize the chemical and structural properties of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} (here after as L2SF55T) specimen, which was subject to measurements of neutron diffraction from room temperature to 900 C. It was found that space group of R3c yielded a better refinement than a cubic structure of Pm3m. Oxygen occupancy was nearly 3 in the region from room temperature to 700 C, above which the occupancy decreased due to oxygen loss. Dense OTM bars provided by Praxair were loaded to fracture at varying stress rates. Studies were done at room temperature in air and at 1000 C in a specified environment to evaluate slow crack growth behavior. The X-Ray data and fracture mechanisms points to non-equilibrium decomposition of the LSFCO OTM membrane. The non-equilibrium conditions could probably be due to the nature of the applied stress field (stressing rates) and leads to transition in crystal structures and increased kinetics of decomposition. The formations of a Brownmillerite or Sr2Fe2O5 type structures, which are orthorhombic are attributed to the ordering of oxygen vacancies. The cubic to orthorhombic transitions leads to 2.6% increase in strains and thus residual stresses generated could influence the fracture behavior of the OTM membrane. Continued investigations on the thermodynamic properties (stability and phase-separation behavior) and total conductivity of prototype membrane materials were carried out. The data are needed together with the kinetic information to develop a complete model for the membrane transport. Previously characterization, stoichiometry and conductivity measurements for samples of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} were reported. In this report, measurements of the chemical and thermal expansion as a function of temperature and p{sub O2} are described.

S. Bandopadhyay; N. Nagabhushana; X.-D Zhou; Q. Cai; J. Yang; W.B. Yelon; W.J. James; H.U. Anderson; Alan Jacobson; C.A. Mims

2004-05-01T23:59:59.000Z

359

Cold crucible induction melter studies for making glass ceramic waste forms: A feasibility assessment  

SciTech Connect

Glass ceramics are being developed to immobilize fission products, separated from used nuclear fuel by aqueous reprocessing, into a stable waste form suitable for disposal in a geological repository. This work documents the glass ceramic formulation at bench scale and for a scaled melter test performed in a pilot-scale (approximately 1/4 scale) cold crucible induction melter (CCIM). Melt viscosity, electrical conductivity, and crystallization behavior upon cooling were measured on a small set of compositions to select a formulation for melter testing. Property measurements also identified a temperature range for melter operation and cooling profiles necessary to crystallize the targeted phases in the waste form. Bench scale and melter run results successfully demonstrate the processability of the glass ceramic using the CCIM melter technology.

Jarrod Crum [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Vince Maio [Idaho National Laboratory (INL), Idaho Falls, ID (United States); John McCloy [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Clark Scott [Idaho National Laboratory (INL), Idaho Falls, ID (United States); Brian Riley [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Brad Benefiel [Idaho National Laboratory (INL), Idaho Falls, ID (United States); John Vienna [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Kip Archibald [Idaho National Laboratory (INL), Idaho Falls, ID (United States); Carmen Rodriguez [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Veronica Rutledge [Idaho National Laboratory (INL), Idaho Falls, ID (United States); Zihua Zhu [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Joe Ryan [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Matthew Olszta [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)

2014-01-01T23:59:59.000Z

360

Oxygen Transport Ceramic Membranes  

SciTech Connect

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 Ti-substituted perovskites, La{sub 0.7}Sr{sub 0.3}Mn{sub 1-x}Ti{sub x}O{sub 3}, with 0 {le} x {le} 0.20, were investigated by neutron diffraction, magnetization, electric resistivity, and magnetoresistance (MR) measurements. All samples show a rhombohedral structure (space group R3C) from 10 K to room temperature. At room temperature, the cell parameters a, c and the unit cell volume increase with increasing Ti content. However, at 10 K, the cell parameter a has a maximum value for x = 0.10, and decreases for x > 0.10, while the unit cell volume remains nearly constant for x > 0.10. The average (Mn,Ti)-O bond length increases up to x = 0.15, and the (Mn,Ti)-O-(Mn,Ti) bond angle decreases with increasing Ti content to its minimum value at x = 0.15 at room temperature. Below the Curie temperature TC, the resistance exhibits metallic behavior for the x {le} 0.05 samples. A metal (semiconductor) to insulator transition is observed for the x {ge} 0.10 samples. A peak in resistivity appears below TC for all samples, and shifts to a lower temperature as x increases. The substitution of Mn by Ti decreases the 2p-3d hybridization between O and Mn ions, reduces the bandwidth W, and increases the electron-phonon coupling. Therefore, the TC shifts to a lower temperature and the resistivity increases with increasing Ti content. A field-induced shift of the resistivity maximum occurs at x {le} 0.10 compounds. The maximum MR effect is about 70% for La{sub 0.7}Sr{sub 0.3}Mn{sub 0.8}Ti{sub 0.2}O{sub 3}. The separation of TC and the resistivity maximum temperature T{sub {rho},max} enhances the MR effect in these compounds due to the weak coupling between the magnetic ordering and the resistivity as compared with La{sub 0.7}Sr{sub 0.3}MnO{sub 3}. The bulk densities of the membranes were determined using the Archimedes method. The bulk density was 5.029 and 5.57 g/cc for LSFT and dual phase membranes, respectively. The microstructure of the dual phase membrane was analyzed using SEM. It is evident from the micrograph that the microstructure is composed of dual phases. The dense circular regions are enclosed by the less dense, continuous phase which accommodates most of the pores. The pores are normally aggregated and found clustered along the dense regions where as the dense regions do not have pores. Upon closer observation of the micrograph it is revealed that the dense region has a clear circular cleavage or crack as their boundary. The circular cleavage clearly encompasses a dense region and which consists of no pore or any flaw that is visible. The size distribution of the dense, discontinuous regions is varying from 5 to 20 {micro}m with a D{sub 50} of 15 {micro}m. The grain size distribution was estimated from the micrographs using image analysis and a unimodal distribution of grains was observed with an average grain size of 1.99 {micro}m. The chemical compositions of the membranes were analyzed using EDS analysis and no other impurities were observed. The XRD analysis was carried out for the membranes and the phase purity was confirmed. The fracture toughness of LSFT membranes at room temperature has to be calculated using the Vickers indentation method. An electrochemical cell has been designed and built for measurements of the ionic conductivity by the use of blocking electrodes. Preliminary measurements on La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} are reported. Modifications to the apparatus to improve the data quality have been completed. Electron microscopy studies of the origin of the slow kinetics on reduction of ferrites have been initiated. 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 gradient

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

2005-05-01T23:59:59.000Z

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

Impact and energy absorption of laminated and sandwich composites  

E-Print Network (OSTI)

Advanced fiber reinforced composites combine high specific strength and stiffness. Advanced composites are currently being introduced into modern U.S. Navy ships to achieve weight savings, maintenance reduction, and signature ...

Kilic, Yavuz, S.M. Massachusetts Institute of Technology

2008-01-01T23:59:59.000Z

362

Oxygen Transport Ceramic Membranes  

SciTech Connect

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 this report, in situ neutron diffraction was used to characterize the chemical and structural properties of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} (here after as L2SF55T) specimen, which was subject to measurements of neutron diffraction from room temperature to 900 C in N{sub 2}. Space group of R3c was found to result in a better refinement and is used in this study. The difference for crystal structure, lattice parameters and local crystal chemistry for LSFT nearly unchanged when gas environment switched from air to N{sub 2}. Stable crack growth studies on Dense OTM bars provided by Praxair were done at room temperature in air. A bridge-compression fixture was fabricated to achieve stable pre-cracks from Vickers indents. Post fracture evaluation indicated stable crack growth from the indent and a regime of fast fracture. Post-fracture X-ray data of the OTM fractured at 1000 C in environment were refined by FullProf code and results indicate a distortion of the parent cubic perovskite to orthorhombic structure with reduced symmetry. TGA-DTA studies on the post-fracture samples also indicated residual effect arising from the thermal and stress history of the samples. The thermal and chemical expansion of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} were studied at 800 {le} T {le} 1000 C and at {approx} 1 x 10{sup -15} {le} pO{sub 2} {le} 0.21 atm. The thermal expansion coefficient of the sample was calculated from the dilatometric analysis in the temperature range between room temperature and 1200 C in air. 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; X.-D Zhou; Q. Cai; J. Yang; W.B. Yelon; W.J. James; H.U. Anderson; Alan Jacobson; C.A. Mims

2004-05-01T23:59:59.000Z

363

Oxygen Transport Ceramic Membranes  

SciTech Connect

Ti doping on La{sub 1-x}Sr{sub x}FeO{sub 3-{delta}} (LSF) tends to increase the oxygen equilibration kinetics of LSF in lower oxygen activity environment because of the high valence state of Ti. However, the addition of Ti decreases the total conductivity because the acceptor ([Sr{prime}{sub La}]) is compensated by the donor ([Ti{sub Fe}{sup {sm_bullet}}]) which decreases the carrier concentration. The properties of La{sub 0.2}Sr{sub 0.8}Fe{sub 1-x}Ti{sub x}O{sub 3-{delta}} (LSFT, x = 0.45) have been experimentally and theoretically investigated to elucidate (1) the dependence of oxygen occupancy and electrochemical properties on temperature and oxygen activity by thermogravimetric analysis (TGA) and (2) the electrical conductivity and carrier concentration by Seebeck coefficient and electrical measurements. In the present study, dual phase (La{sub 0.2}Sr{sub 0.8}Fe{sub 0.6}Ti{sub 0.4}O{sub 3-{delta}}/Ce{sub 0.9}Gd{sub 0.1}O{sub 2-{delta}}) membranes have been evaluated for structural properties such as hardness, fracture toughness and flexural strength. The effect of high temperature and slightly reducing atmosphere on the structural properties of the membranes was studied. The flexural strength of the membrane decreases upon exposure to slightly reducing conditions at 1000 C. The as-received and post-fractured membranes were characterized using XRD, SEM and TG-DTA to understand the fracture mechanisms. Changes in structural properties of the composite were sought to be correlated with the physiochemical features of the two-phases. We have reviewed the electrical conductivity data and stoichiometry data for La{sub 0.2}Sr{sub 0.8}Cr{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} some of which was reported previously. Electrical conductivity data for La{sub 0.2}Sr{sub 0.8}Cr{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} (LSCrF) were obtained in the temperature range, 752 {approx} 1055 C and in the pO{sub 2} range, 10{sup -18} {approx} 0.5 atm. The slope of the plot of log {sigma} vs. log pO{sub 2} is {approx} 1/5 in the p-type region, pO{sub 2} = 10{sup -5} {approx} 10{sup -1} atm. The pO{sub 2} at which the p-n transition is observed increases with increasing temperature. The activation energy for ionic conduction was estimated to be 0.86 eV from an Arrhenius plot of the minimum conductivity vs. reciprocal temperature. At temperatures below 940 C, a plateau in the conductivity isotherm suggests the presence of a two-phase region. Most likely, phase separation occurs to form a mixture of a perovskite phase and an oxygen vacancy ordered phase related to brownmillerite. Additional data for the oxygen non stoichiometry are presented.

S. Bandopadhyay; T. Nithyanantham

2006-12-31T23:59:59.000Z

364

Glass and glass-ceramics transparent from the visible range to the mid-infrared for night vision  

Science Journals Connector (OSTI)

Many papers report studies on oxyfluorides glass-ceramics combining the optical advantage of fluoride environment for rare earth with the thermal and chemical advantages of oxide glasses [1â??7], or on oxide-based glass-ceramics exhibiting exceptional thermo-mechanical properties such as zero thermal expansion coefficient. The transparency of these glass-ceramics is limited in the infrared region up to 4 µm [8â??12]. In this paper, we report the last results on totally new infrared transmitting chalcogenide glass-ceramics which are transparent up to 11 µm for sulphur based glass or up to 16 µm for selenium based glass. By selecting appropriate glass composition in several Ge-(Sb/Ga)-(S/Se)-MX (MX: alkali halide) systems, glass-ceramics with different microcrystals volume fraction can be reproducibly obtained by controlling nucleation and crystallisation annealing time and temperatures. It has been demonstrated that crystals smaller than 200 nm induce some additional losses only in the short wavelength region. The glass ceramics keep the same transmission as the original glass from 1 µm up to 11 µm or 16 µm. Sulphur based glass-ceramics are still transparent in the second for glass and selenium based glass-ceramics keep an excellent transmission in the second and third atmospheric window. The obtained glass-ceramics exhibit much better resistance to cracks propagation than the corresponding pure glass matrix. Observations under electronic microscopy as well as X-ray diffraction have been used to determinate crystals size, density and crystalline phase. The possibility of combining the ceramisation process and the shaping by moulding has also been demonstrated.

L. Calvez; H-L. Ma; J. Lucas; X.H. Zhang

2008-01-01T23:59:59.000Z

365

Formation of thin walled ceramic solid oxide fuel cells  

DOE Patents (OSTI)

To reduce thermal stress and improve bonding in a high temperature monolithic solid oxide fuel cell (SOFC), intermediate layers are provided between the SOFC's electrodes and electrolyte which are of different compositions. The intermediate layers are comprised of a blend of some of the materials used in the electrode and electrolyte compositions. Particle size is controlled to reduce problems involving differential shrinkage rates of the various layers when the entire structure is fired at a single temperature, while pore formers are provided in the electrolyte layers to be removed during firing for the formation of desired pores in the electrode layers. Each layer includes a binder in the form of a thermosetting acrylic which during initial processing is cured to provide a self-supporting structure with the ceramic components in the green state. A self-supporting corrugated structure is thus formed prior to firing, which the organic components of the binder and plasticizer removed during firing to provide a high strength, high temperature resistant ceramic structure of low weight and density.

Claar, Terry D. (Tisle, IL); Busch, Donald E. (Hinsdale, IL); Picciolo, John J. (Lockport, IL)

1989-01-01T23:59:59.000Z

366

Dale Haracre Ceramics In a Patch Antenna  

E-Print Network (OSTI)

Dale Haracre Ceramics In a Patch Antenna #12;Abstract A patch antenna is also known on a flat surface. Ceramic based patched antennas can be used for a wide range of applications.They can:Wi-Fi,WiMAX &Wireless Broadband,WLAN & ISM, and RFID & ISM.The also play a major part in GPS signals. Patch antennas

Mukhopadhyay, Sharmila M.

367

Neutron apparatus for measuring strain in composites  

DOE Patents (OSTI)

A method and apparatus for orienting a pulsed neutron source and a multi-angle diffractometer toward a sample of a ceramic-matrix or metal-matrix composite so that the measurement of internal strain (from which stress is calculated) is reduced to uncomplicated time-of-flight measurements.

Kupperman, David S. (Oak Park, IL); Majumdar, Saurindranath (Naperville, IL); Faber, Jr., John F. (Downers Grove, IL); Singh, J. P. (Bolingbrook, IL)

1990-01-01T23:59:59.000Z

368

Pressurized heat treatment of glass ceramic  

DOE Patents (OSTI)

A method of producing a glass-ceramic having a specified thermal expansion value is disclosed. The method includes the step of pressurizing the parent glass material to a predetermined pressure during heat treatment so that the glass-ceramic produced has a specified thermal expansion value. Preferably, the glass-ceramic material is isostatically pressed. A method for forming a strong glass-ceramic to metal seal is also disclosed in which the glass-ceramic is fabricated to have a thermal expansion value equal to that of the metal. The determination of the thermal expansion value of a parent glass material placed in a high-temperature environment is also used to determine the pressure in the environment.

Kramer, D.P.

1984-04-19T23:59:59.000Z

369

Advance Waivers - 1994 | Department of Energy  

NLE Websites -- All DOE Office Websites (Extended Search)

4 4 Advance Waivers - 1994 The following Advance Waivers are available: WA 1994 001 TEXACO EXPLORATION AND PRODUCTION Waiver of Dome.pdf WA 1994 002 SOLARCHEM ENTERPRISES INC Waiver of Domestic and.pdf WA 1994 003 GOLDEN PHOTOCON INC Waiver of Domestic and Forei.pdf WA 1994 004 ALUMINUM COMPANY OF AMERICA Waiver of Domestic a.pdf WA 1994 005 ARTHUR D LITTLE INC Waiver of Domestic and Forei.pdf WA 1994 006 PENNSYLVANIA ELECTRIC COMPANY Waiver of Domestic.pdf WA 1994 007 KYOCERA INDUSTRIAL CERAMICS CORPORATION Waiver o.pdf WA 1994 008 GOLDEN TECHNOLOGIES COMPANY Waiver of Domestic a.pdf WA 1994 009 SAINT-BOBAIN-NORTON INDUSTRIAL CERAMICS CORPORAT.pdf WA 1994 010 SCHWITZER U.S. INC Waiver of Domestic and Foreig.pdf WA 1994 011 EATON CORPORATION Waiver of Domestic and Foreign.pdf

370

Melted Murataite Ceramics Containing Simulated Actinide/Rare Earth Fraction of High Level Waste  

SciTech Connect

Murataite-based ceramics with three different chemical compositions containing simulated actinide/rare earth (RE) fraction of HLW were produced in a resistive furnace at a temperature of 1500 deg. C and two of them - in a cold crucible energized from a 5.28 MHz/10 kW high frequency generator. All the samples prepared in resistive furnace were composed of major murataite and minor perovskite, crichtonite, zirconolite, and pyrophanite/ilmenite. The samples produced in the cold crucible were composed of murataite, perovskite, crichtonite, and rutile. Higher content of perovskite and crichtonite in the cold crucible melted ceramic than in the ceramic with the same chemical composition but melted in resistive furnace may be due to higher temperature in the cold crucible (up to 1600-1650 deg. C) at which some fraction of murataite was subjected to decomposition yielding additional amount of perovskite and crichtonite. Method of melting may effect on elemental partitioning in the murataite-containing ceramics because light (Ce-group) REs enter preferably perovskite phase whereas Nd, Sm, and heavy (Y-group) REs are accommodated in the murataite polytypes. Thus, perovskite and murataite are major host phases for the Ce- and Y-group REs, respectively, whereas tetravalent actinides (U) enter murataite only.

Stefanovsky, S.V.; Ptashkin, A.G.; Knyazev, O.A.; Zen'kovskaya, M.S.; Stefanovsky, O.I. [State Unitary Enterprise SIA Radon, Moscow (Russian Federation); Yudintsev, S.V.; Nikonov, B.S.; Lapina, M.I. [Institute of Geology of Ore Deposits, Petrography, Mineralogy and Geochemistry of the Russian, Academy of Sciences (IGEM RAS), Moscow (Russian Federation)

2008-07-01T23:59:59.000Z

371

Advancement of Electrochromic Windows  

E-Print Network (OSTI)

of a thin-film ceramic electrochromic window: Field studyof a Thin-Film Ceramic Electrochromic Window: Field StudyEC window product characteristics The EC is a thin-film WO3-

2006-01-01T23:59:59.000Z

372

Microwave processing for carbide ceramics  

SciTech Connect

The US Bureau of Mines (USBM) has developed a process for synthesizing carbide ceramics in a microwave-induced plasma (MIP). For example, the process forms tungsten carbide with only 0.04% free carbon impurity at an average particle size of 0.05 {mu}m. Starting materials are tungsten oxide, carbon, and carbon monoxide. Commercial methods to produce tungsten carbide require heating to 1,500 C for up to 7 hours. Using the USBM method, tungsten carbide can be produced in approximately 10 minutes using a 30 kW, 915 mHz microwave unit. The reaction is carried out in a short-circuited waveguide to create a standing wave. Reactants rest on a carbon pedestal inside a closed zirconia crucible filled with carbon monoxide. The crucible is place at a field maximum within the waveguide. The waveguide was filled with helium to protect the waveguide. A procedure for producing carbide on a larger scale is described. Other ceramic compounds have been produced using this method, including silicon carbide and titanium carbide.

Tolley, W.K.; Church, R.H. [Bureau of Mines, Salt Lake City, UT (United States). Salt Lake City Research Center

1995-08-01T23:59:59.000Z

373

QUANTITATIVE STUDIES OF THERMAL SHOCK IN CERAMICS BASED ON A NOVEL TEST TECHNIQUE  

E-Print Network (OSTI)

QUANTITATIVE STUDIES OF THERMAL SHOCK IN CERAMICS BASED ON AQUANTITATIVE STUDIES OF THERMAL SHOCK IN CERAMICS BASED ON AAl 203). The thermal failure of another ceramic material (

Faber, K.T.

2013-01-01T23:59:59.000Z

374

Advanced Wear-resistant Nanocomposites for Increased Energy Efficiency  

SciTech Connect

This report summarizes the work performed by an Ames-led project team under a 4-year DOE-ITP sponsored project titled, 'Advanced Wear-resistant Nanocomposites for Increased Energy Efficiency.' The Report serves as the project deliverable for the CPS agreement number 15015. The purpose of this project was to develop and commercialize a family of lightweight, bulk composite materials that are highly resistant to degradation by erosive and abrasive wear. These materials, based on AlMgB{sub 14}, are projected to save over 30 TBtu of energy per year when fully implemented in industrial applications, with the associated environmental benefits of eliminating the burning of 1.5 M tons/yr of coal and averting the release of 4.2 M tons/yr of CO{sub 2} into the air. This program targeted applications in the mining, drilling, machining, and dry erosion applications as key platforms for initial commercialization, which includes some of the most severe wear conditions in industry. Production-scale manufacturing of this technology has begun through a start-up company, NewTech Ceramics (NTC). This project included providing technical support to NTC in order to facilitate cost-effective mass production of the wear-resistant boride components. Resolution of issues related to processing scale-up, reduction in energy intensity during processing, and improving the quality and performance of the composites, without adding to the cost of processing were among the primary technical focus areas of this program. Compositional refinements were also investigated in order to achieve the maximum wear resistance. In addition, synthesis of large-scale, single-phase AlMgB{sub 14} powder was conducted for use as PVD sputtering targets for nanocoating applications.

Cook, B. A.; Harringa, J. L.; Russel, A. M.

2012-12-01T23:59:59.000Z

375

Nonlinear dielectric response of periodic composite materials A. Kolpakov & A. K. Tagantsev & L. Berlyand &  

E-Print Network (OSTI)

periodic composite (a matrix of a large dielectric constant ferro- electric material with linear dielectric of ferroelectric/dielectric composites. A typical example is a (Ba,Sr)TiO3 ceramic fabricated with addition of MgNonlinear dielectric response of periodic composite materials A. Kolpakov & A. K. Tagantsev & L

Berlyand, Leonid

376

Rsistance au dommage local de basse nergie d'un composite SiC/SiC  

E-Print Network (OSTI)

. These results can be compared to impact resistance of ceramic matrix composites published in the literatureRĂ©sistance au dommage local de basse Ă©nergie d'un composite SiC/SiC Resistance to Low Energy Impact Damage for a SiC/SiC Composite Vincent Herb 1 , Eric Martin 1 et Jacques Lamon 1 1 : Laboratoire des

Paris-Sud XI, Université de

377

Filtering diesel exhaust gases with ceramic filters  

Science Journals Connector (OSTI)

Results are given from three test series on a ceramic filter for diesel exhausts. In the first and second series, use was made of diesel fuel (in the summer), while in...

A. Yu. Val’dberg; A. N. Tsedilin; T. O. Kosogorova…

2008-03-01T23:59:59.000Z

378

Metal Encapsulation of Ceramic Nuclear Waste  

Science Journals Connector (OSTI)

A conceptual flow sheet is presented for encapsulating a ceramic waste form in solid lead, using existing or ... encapsulation might be applied to other solid radioactive wastes from the nuclear fuel cycle. It is...

L. J. Jardine; M. J. Steindler

1979-01-01T23:59:59.000Z

379

Metallic nut for use with ceramic threads  

DOE Patents (OSTI)

A nozzle guide vane assembly has ceramic components therein having a conventional thread thereon including a preestablished pitch and having a preestablished rate of thermal expansion. The nozzle guide vane assembly has a metallic components therein having a preestablished rate of thermal expansion being greater that the rate of thermal expansion of the ceramic components is positioned in a gas turbine engine. The metallic component, a nut, has a thread therein including a plurality of crests being spaced on a pitch equal to that of the ceramic component and has a pair of contacting surfaces extending from the plurality of crests. A notch spirally extends intermediate adjacent ones of the plurality of crests and has a preestablished depth which is at least twice the size of the conventional pitch. Furthermore, the pair of contacting surfaces are in contact with only a portion of the threaded surface of the ceramic components.

Norton, Paul F. (San Diego, CA); Shaffer, James E. (Maitland, FL)

1996-01-01T23:59:59.000Z

380

Ceramic Cross Flow Recuperator Design Parameters  

E-Print Network (OSTI)

GTE Products Corporation has developed a compact ceramic cross flow recuperator for high temperature industrial heat recovery applications. They recently completed a jointly funded project with the DOE, (Contract #EX-76-C-0 1-2162) to demonstrate...

Gonzalez, J. M.; Rebello, W. J.

1981-01-01T23:59:59.000Z

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.


381

High temperature alkali corrosion of ceramics in coal gas. Quarterly progress report No. 3, March 1, 1992--May 31, 1992  

SciTech Connect

High temperature alkali corrosion has been known to cause premature failure of ceramic components used in advanced high temperature coal combustion systems such as coal gasification and clean-up, coal fired gas turbines, and high efficiency heat engines. The objective of this research is to systematically evaluate the alkali corrosion resistance of the most commonly used structural ceramics including silicon carbide, silicon nitride, cordierite, mullite, alumina, aluminum titanate, zirconia, and fireclay glass. The study consists of identification of the alkali reaction products (phase equilibria) and the kinetics of the alkali reactions as a function of temperature and time.

Pickrell, G.R.; Sun, T.; Brown, J.J.

1992-05-27T23:59:59.000Z

382

Crystal structure of Sr-akermanite glass–ceramics  

Science Journals Connector (OSTI)

A glass–ceramic of Sr-akermanite (Sr2MgSi2O7, SG: P 4 Ż 2 1 m ) was prepared by crystallization of a glass with composition of 2SrOMgO3SiO2. Parameters of the crystal structure were refined by Rietveld method. The analysis of the experimental results showed the following: the unit cell of Sr-akermanite in the glass–ceramic is larger than in single crystal. The thermal expansion coefficients of Sr-akermanite, calculated from the lattice constants obtained from X-ray diffractograms at high temperatures, were ?a = 3.663 × 10?6 K?1 and ?c = 6.666 × 10?6 K?1. It is suggested that the atomic displacements from the atomic coordination in single crystal depend on the stress developed during the crystallization process and the thermal contraction stress developed during cooling. Both types of stresses are related to the presence of residual glass and should be responsible for the expansion of the crystal lattice.

Yasuo Ochi

2006-01-01T23:59:59.000Z

383

Crystal structure of Sr-akermanite glass-ceramics  

SciTech Connect

A glass-ceramic of Sr-akermanite (Sr{sub 2}MgSi{sub 2}O{sub 7}, SG: P4-bar 2{sub 1}m) was prepared by crystallization of a glass with composition of 2SrO?MgO?3SiO{sub 2}. Parameters of the crystal structure were refined by Rietveld method. The analysis of the experimental results showed the following: the unit cell of Sr-akermanite in the glass-ceramic is larger than in single crystal. The thermal expansion coefficients of Sr-akermanite, calculated from the lattice constants obtained from X-ray diffractograms at high temperatures, were {alpha}{sub a}=3.663x10{sup -6}K{sup -1} and {alpha}{sub c}=6.666x10{sup -6}K{sup -1}. It is suggested that the atomic displacements from the atomic coordination in single crystal depend on the stress developed during the crystallization process and the thermal contraction stress developed during cooling. Both types of stresses are related to the presence of residual glass and should be responsible for the expansion of the crystal lattice.

Ochi, Yasuo [Research and Development Division, Ohara Incorporated Company, Naka 2-22-28, Kunitachi, Tokyo (Japan)]. E-mail: yasuo_ochi@ybb.ne.jp

2006-10-12T23:59:59.000Z

384

Advanced Hydrogen Transport Membranes for Vision 21 Fossil Fuel Plants  

SciTech Connect

Eltron Research Inc. and team members CoorsTek, Sued Chemie, Argonne National Laboratory, and NORAM are developing an environmentally benign, inexpensive, and efficient method for separating hydrogen from gas mixtures produced during industrial processes, such as coal gasification. This project was motivated by the National Energy Technology Laboratory (NETL) Vision 21 initiative, which seeks to economically eliminate environmental concerns associated with the use of fossil fuels. Currently, this project is focusing on four basic categories of dense membranes: (1) mixed conducting ceramic/ceramic composites, (2) mixed conducting ceramic/metal (cermet) composites, (3) cermets with hydrogen permeable metals, and (4) layered composites containing hydrogen permeable alloys. Ultimately, these materials must enable hydrogen separation at practical rates under ambient and high-pressure conditions, without deactivation in the presence of feedstream components such as carbon dioxide, water, and sulfur. During this final quarter of the no cost extension several planar membranes of a cermet composition referred to as EC101 containing a high permeability metal and a ceramic phase were prepared and permeability testing was performed.

Carl R. Evenson; Richard N. Kleiner; James E. Stephan; Frank E. Anderson

2006-04-30T23:59:59.000Z

385

Advanced Hydrogen Transport Membranes for Vision 21 Fossil Fuel Plants  

SciTech Connect

During this quarter of the no cost extension a cermet composition referred to as EC101 containing a high permeability metal and a ceramic phase was prepared for sealing and permeability testing. Several different types of seals were developed and tested. In addition membrane surface stability was characterized.

Carl R. Evenson; Richard N. Kleiner; James E. Stephan; Frank E. Anderson

2006-01-31T23:59:59.000Z

386

Applications in the Nuclear Industry for Thermal Spray Amorphous Metal and Ceramic Coatings  

E-Print Network (OSTI)

SAW Amorphous metal and ceramic thermal spray coatings havefor Thermal Spray Amorphous Metal and Ceramic Coatings J.

Blink, J.; Farmer, J.; Choi, J.; Saw, C.

2009-01-01T23:59:59.000Z

387

Improved Properties of Pb Based BLZT Ferroelectric Ceramics  

SciTech Connect

Present report is concerning with investigation of effect of different sintering profiles on Pb based BLZT ceramics. The material powder of selected composition (Ba{sub 0.795}La{sub 0.005}Pb{sub 0.20}Ti{sub 0.90}Zr{sub 0.10}O{sub 3}) was prepared by solid state reaction route and then powder was compacted in the form of circular discs. The discs were then sintered at different temperatures (1325 deg. C for 4h, 1325 deg. C for 15min+1200 deg. C for 4h). Improved dielectric and ferroelectric properties were observed for samples sintered at 1200 deg. C. Shifting in T{sub c} to higher temperature could be related to enhanced tetragonality, which was further confirmed by X-ray diffraction analysis. All these improvements evidences that there is less Pb loss in case of modified sintering profile.

Kumar, Parveen [Electroceramics Research Lab, GVM Girls College, Sonepat-131001 (India); School of Physics and Material Science, Thapar University, Patiala-147004 (India); Singh, Sangeeta [Department of Physics, GVM Girls College, Sonepat-131001 (India); Juneja, J. K. [Department of Physics, Hindu College, Sonepat-131001 (India); Raina, K. K. [School of Physics and Material Science, Thapar University, Patiala-147004 (India); Prakash, Chandra [Directorate of ER and IPR, DRDO, DRDO Bhawan, New Delhi-110105 (India)

2011-11-22T23:59:59.000Z

388

Optical method and apparatus for detection of surface and near-subsurface defects in dense ceramics  

DOE Patents (OSTI)

A laser is used in a non-destructive manner to detect surface and near-subsurface defects in dense ceramics and particularly in ceramic bodies with complex shapes such as ceramic bearings, turbine blades, races, and the like. The laser`s wavelength is selected based upon the composition of the ceramic sample and the laser can be directed on the sample while the sample is static or in dynamic rotate or translate motion. Light is scattered off surface and subsurface defects using a preselected polarization. The change in polarization angle is used to select the depth and characteristics of surface/subsurface defects. The scattered light is detected by an optical train consisting of a charge coupled device (CCD), or vidicon, television camera which, in turn, is coupled to a video monitor and a computer for digitizing the image. An analyzing polarizer in the optical train allows scattered light at a given polarization angle to be observed for enhancing sensitivity to either surface or near-subsurface defects. Application of digital image processing allows subtraction of digitized images in near real-time providing enhanced sensitivity to subsurface defects. Storing known ``feature masks`` of identified defects in the computer and comparing the detected scatter pattern (Fourier images) with the stored feature masks allows for automatic classification of detected defects. 29 figs.

Ellingson, W.A.; Brada, M.P.

1995-06-20T23:59:59.000Z

389

Optical method and apparatus for detection of surface and near-subsurface defects in dense ceramics  

DOE Patents (OSTI)

A laser is used in a non-destructive manner to detect surface and near-subsurface defects in dense ceramics and particularly in ceramic bodies with complex shapes such as ceramic bearings, turbine blades, races, and the like. The laser's wavelength is selected based upon the composition of the ceramic sample and the laser can be directed on the sample while the sample is static or in dynamic rotate or translate motion. Light is scattered off surface and subsurface defects using a preselected polarization. The change in polarization angle is used to select the depth and characteristics of surface/subsurface defects. The scattered light is detected by an optical train consisting of a charge coupled device (CCD), or vidicon, television camera which, in turn, is coupled to a video monitor and a computer for digitizing the image. An analyzing polarizer in the optical train allows scattered light at a given polarization angle to be observed for enhancing sensitivity to either surface or near-subsurface defects. Application of digital image processing allows subtraction of digitized images in near real-time providing enhanced sensitivity to subsurface defects. Storing known "feature masks" of identified defects in the computer and comparing the detected scatter pattern (Fourier images) with the stored feature masks allows for automatic classification of detected defects.

Ellingson, William A. (Naperville, IL); Brada, Mark P. (Goleta, CA)

1995-01-01T23:59:59.000Z

390

Method of producing a carbon coated ceramic membrane and associated product  

DOE Patents (OSTI)

A method is described for producing a carbon coated ceramic membrane including passing a selected hydrocarbon vapor through a ceramic membrane and controlling ceramic membrane exposure temperature and ceramic membrane exposure time. The method produces a carbon coated ceramic membrane of reduced pore size and modified surface properties having increased chemical, thermal and hydrothermal stability over an uncoated ceramic membrane. 12 figures.

Liu, P.K.T.; Gallaher, G.R.; Wu, J.C.S.

1993-11-16T23:59:59.000Z

391

Method of producing a carbon coated ceramic membrane and associated product  

DOE Patents (OSTI)

A method of producing a carbon coated ceramic membrane including passing a selected hydrocarbon vapor through a ceramic membrane and controlling ceramic membrane exposure temperature and ceramic membrane exposure time. The method produces a carbon coated ceramic membrane of reduced pore size and modified surface properties having increased chemical, thermal and hydrothermal stability over an uncoated ceramic membrane.

Liu, Paul K. T. (O'Hara Township, Allegheny County, PA); Gallaher, George R. (Oakmont Borough, PA); Wu, Jeffrey C. S. (Pittsburgh, PA)

1993-01-01T23:59:59.000Z

392

Phase III Advanced Anodes and Cathodes Utilized in Energy Efficient Aluminum Production Cells  

SciTech Connect

During Phase I of the present program, Alcoa developed a commercial cell concept that has been estimated to save 30% of the energy required for aluminum smelting. Phase ii involved the construction of a pilot facility and operation of two pilots. Phase iii of the Advanced Anodes and Cathodes Program was aimed at bench experiments to permit the resolution of certain questions to be followed by three pilot cells. All of the milestones related to materials, in particular metal purity, were attained with distinct improvements over work in previous phases of the program. NiO additions to the ceramic phase and Ag additions to the Cu metal phase of the cermet improved corrosion resistance sufficiently that the bench scale pencil anodes met the purity milestones. Some excellent metal purity results have been obtained with anodes of the following composition: Further improvements in anode material composition appear to be dependent on a better understanding of oxide solubilities in molten cryolite. For that reason, work was commissioned with an outside consultant to model the MeO - cryolite systems. That work has led to a better understanding of which oxides can be used to substitute into the NiO-Fe2O3 ceramic phase to stabilize the ferrites and reduce their solubility in molten cryolite. An extensive number of vertical plate bench electrolysis cells were run to try to find conditions where high current efficiencies could be attained. TiB2-G plates were very inconsistent and led to poor wetting and drainage. Pure TiB2 did produce good current efficiencies at small overlaps (shadowing) between the anodes and cathodes. This bench work with vertical plate anodes and cathodes reinforced the importance of good cathode wetting to attain high current efficiencies. Because of those conclusions, new wetting work was commissioned and became a major component of the research during the third year of Phase III. While significant progress was made in several areas, much work needs to be done. The anode composition needs further improvements to attain commercial purity targets. At the present corrosion rate, the vertical plate anodes will wear too rapidly leading to a rapidly increasing anode-cathode gap and thermal instabilities in the cell. Cathode wetting as a function of both cathode plate composition and bath composition needs to be better understood to ensure that complete drainage of the molten aluminum off the plates occurs. Metal buildup appears to lead to back reaction and low current efficiencies.

R.A. Christini; R.K. Dawless; S.P. Ray; D.A. Weirauch, Jr.

2001-11-05T23:59:59.000Z

393

Rolling Contact Fatigue of Ceramics  

SciTech Connect

High hardness, low coefficient of thermal expansion and high temperature capability are properties also suited to rolling element materials. Silicon nitride (Si{sub 3}N{sub 4}) has been found to have a good combination of properties suitable for these applications. However, much is still not known about rolling contact fatigue (RCF) behavior, which is fundamental information to assess the lifetime of the material. Additionally, there are several test techniques that are employed internationally whose measured RCF performances are often irreconcilable. Due to the lack of such information, some concern for the reliability of ceramic bearings still remains. This report surveys a variety of topics pertaining to RCF. Surface defects (cracks) in Si{sub 3}N{sub 4} and their propagation during RCF are discussed. Five methods to measure RCF are then briefly overviewed. Spalling, delamination, and rolling contact wear are discussed. Lastly, methods to destructively (e.g., C-sphere flexure strength testing) and non-destructively identify potential RCF-limiting flaws in Si{sub 3}N{sub 4} balls are described.

Wereszczak, Andrew A [ORNL; Wang, W. [Bournemouth University, Bournemouth, United Kingdom; Wang, Y. [Bournemouth University, Bournemouth, United Kingdom; Hadfield, M. [Bournemouth University, Bournemouth, United Kingdom; Kanematsu, W. [National Institute of Advanced Industrial Science and Technology, Japan; Kirkland, Timothy Philip [ORNL; Jadaan, Osama M. [University of Wisconsin, Platteville

2006-09-01T23:59:59.000Z

394

Microwave sintering of nanocrystalline ceramics  

SciTech Connect

A single-mode cavity microwave furnace, operating in the TE{sub 103} mode at 2.45 GHz, has been set up at the Naval Research Laboratory (NRL) and is currently being used to investigate sintering of nanocrystalline ceramics. This presentation will discuss the apparatus used and the results obtained to date. The high purity Al{sub 2}O{sub 3} and TiO{sub 2} nanocrystalline powders were prepared by the sol-gel method. These powders were first uniaxially pressed to 14 MPa, CIP`ed to various pressures > 420 MPa and finally sectioned into wafers. The density of the green wafers was 30 to 38% TD. The wafers were heated in the microwave furnace for up to three hours at temperatures {<=} 1720{degrees}C. The temperature of the workpiece was monitored using an optical pyrometer. Final densities up to 80% TD have been obtained to date for Al{sub 2}O{sub 3} and up to 52% TD for TiO{sub 2}. Work is ongoing to characterize the sintered compacts, optimize the casketing for this furnace, and lay the groundwork for new studies using a 35 GHz gyrotron and quasioptical gyrotron tunable from 85 to 120 GHz.

Bruce, R.W. [United States Naval Academy, Annapolis, MD (United States); Rayne, R.; Chow, G.M. [Naval Research Lab., Washington, DC (United States)] [and others

1995-12-31T23:59:59.000Z

395

High-Temperature Structural Ceramics  

Science Journals Connector (OSTI)

...been made in the diesel engine area as well. Perhaps...advanced concept in diesel tech-nology is the...adiabatic turbo-compounded diesel. This engine would eliminate the...an engine can reduce fuel consumption by as much as 25 percent...

R. Nathan Katz

1980-05-23T23:59:59.000Z

396

Infrared thermography to detect residual ceramic in gas turbine blades  

Science Journals Connector (OSTI)

A serious problem in the production of gas turbine blades is the detection of residual ceramic cores inside the cooling passages; in ... the presence of even small ceramic pieces affects turbine performance and m...

C. Meola; G.M. Carlomagno; M. Di Foggia; O. Natale

2008-06-01T23:59:59.000Z

397

Stochastic optimization of ferroelectric ceramics for piezoelectric applications  

Science Journals Connector (OSTI)

An optimization model and numerical framework is developed to identify the optimal microstructure of ferroelectric (FE) materials. Piezoelectricity in polycrystalline ceramic FEs differs significantly from that of single crystals because of the presence ... Keywords: Ceramics, Ferroelectrics, Homogenization, Piezoelectricity, Stochastic optimization

K. P. Jayachandran; Jose M. Guedes; Helder C. Rodrigues

2011-08-01T23:59:59.000Z

398

The Er3+ : Y2O3 Ceramic System  

E-Print Network (OSTI)

for the thermal expansion coefficient for ceramic yttria orthermal-effect on the refractive index of the similar ceramiceven manage thermal effects to an extent. The use of ceramic

Joshi, Abhijeet

2012-01-01T23:59:59.000Z

399

Processing and Properties of Strontium Bismuth Vanadate Niobate Ferroelectric Ceramics  

E-Print Network (OSTI)

Processing and Properties of Strontium Bismuth Vanadate Niobate Ferroelectric Ceramics Yun Wu, Chau, microstructure, and dielectric properties of strontium bismuth niobate vanadate ceramics, SrBi2(VxNb1 x)2O9 (SBVN

Cao, Guozhong

400

Development and Performance Testing of a New Ceramic Recuperator  

E-Print Network (OSTI)

for heat engine and industrial applications for several years. Durability problems were encountered from thermal stresses in these applications with recuperators made from conventional ceramics. This resulted in development' of a new ceramic mixed oxide...

Kleiner, R. N.

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

Performance study of the ceramic THGEM  

E-Print Network (OSTI)

The THGEMs based on ceramic substrate were developed successfully for neutron and single photon detection. The influences on thermal neutron scattering and the internal radioactivity of both ceramic and FR-4 substrates were studied and compared. The ceramic THGEMs are homemade of 200 um hole diameter, 600 um pitch, 200 um thickness, 80 um rim, and 50 mm*50 mm sensitive area. The FR-4 THGEMs with the same geometry were used for the reference. The gas gain, energy resolution and gain stability were measured in different gas mixtures by using the 5.9 keV X-rays. The maximum gain of single layer ceramic THGEM reaches 6*104 and 1.5*104 at Ne+CH4 = 95:5 and Ar+i-C4H10 = 97:3, respectively. The energy resolution is better than 24%. The good gain stability was obtained during more than 100 hour continuous test at Ar+CO2 = 80:20. By using the 239Pu source, the alpha deposited energy spectrum and gain curve of ceramic THGEM were measured.

Yan, Jia-Qing; Hu, Tao; Lu, Jun-Guang; Zhou, Li; Qu, Guo-Pu; Cai, Xiao; Niu, Shun-Li; Chen, Hai-Tao

2014-01-01T23:59:59.000Z

402

Ceramic membrane treatment of petrochemical wastewater  

SciTech Connect

Ceramic alumina microfiltration membranes were evaluated for treatment of 3 aqueous streams containing heavy metals, oils, and solids at petrochemical manufacturing facilities. To the best of the author's knowledge, this is the first reported use of ceramic alumina membranes for process water and wastewater treatment in a US petrochemical plant. In a pilot test at a vinyl chloride monomer (VCM) plant, precipitated heavy metal solids were filtered with the membranes. On another stream at that site, the ceramic membrane pilot system successfully treated emulsions of 1,2-dichloroethane (EDC), water, and solids. Membrane filtration of a linear alkyl benzene (LAB) oily wastewater stream produced water with less than 5 ppmw oil and grease, after pretreatment with HCl and ferric chloride. A preliminary financial analysis shows that the installed system cost for a ceramic membrane unit is comparable to other membrane technologies, while operating costs are anticipated to be lower. Specific process conditions that are particularly amenable to treatment by ceramic membrane microfiltration are also given in the paper. 10 refs., 11 figs., 7 tabs.

Lahiere, R.J. (Vista Chemical Co., Houston, TX (United States)); Goodboy, K.P.

1993-05-01T23:59:59.000Z

403

Size Effect of SiC Particle on Microstructures and Mechanical Properties of SiCp/Al Composites  

E-Print Network (OSTI)

matrix composites reinforced with ceramic particles have some attractive properties such as high strengthCp/Al composites were fabricated using aluminum alloy ZL101 as the matrix material, and SiC particles a composite is stretched, most of external load transfers from soft Al matrix to hard SiCp reinforcement

Qin, Qinghua

404

Structural Optimization 13, 23-28 (~) Springer-Verlag 1997 Optimal design of 1-3 composite piezoelectrics  

E-Print Network (OSTI)

of a hydrophone composite consisting of parallel piezoceramic rods that are embedded in a porous polymer matrix hydrophone sensitivity can be achieved by making a composite consisting of piezo- ceramic rods in a softStructural Optimization 13, 23-28 (~) Springer-Verlag 1997 Optimal design of 1-3 composite

Torquato, Salvatore

405

Micromechanics applied to the thermal shock behavior of refractory ceramics  

E-Print Network (OSTI)

Micromechanics applied to the thermal shock behavior of refractory ceramics N. Schmitt a,*, A. Burr-phase ceramics subjected to thermal shock. A macroscopic fracture criterion is proposed that accounts for local, F-59 381 Dunkerque, France Received 3 May 2002 Abstract Oxides­carbon refractories are ceramics

406

The effective pyroelectric and thermal expansion coefficients of ferroelectric ceramics  

E-Print Network (OSTI)

The effective pyroelectric and thermal expansion coefficients of ferroelectric ceramics JiangYu Li an estimate on the effective pyroelectric and thermal expansion coefficients of fer- roelectric ceramics, and thermal-medical diagnostics (Cross, 1993). A ceramic made of pyroelectric grains does not necessarily

Li, Jiangyu

407

Simulating Microstructural Evolution and Electrical Transport in Ceramic Gas Sensors  

E-Print Network (OSTI)

. In this paper, using the example of the thermal processing of ceramic gas sensors, an integrated compu- tationalSimulating Microstructural Evolution and Electrical Transport in Ceramic Gas Sensors Yunzhi Wang in ceramic gas sensors has been proposed. First, the particle-flow model and the continuum-phase-field method

Ciobanu, Cristian

408

Robust, high temperature-ceramic membranes for gas separation  

DOE Patents (OSTI)

A method of making ceramic membranes, and the ceramic membranes so formed, comprising combining a ceramic precursor with an organic or inorganic comonomer, forming the combination as a thin film on a substrate, photopolymerizing the thin film, and pyrolyzing the photopolymerized thin film.

Berchtold, Kathryn A.; Young, Jennifer S.

2014-07-29T23:59:59.000Z

409

Advanced Hydrogen Transport Membranes for Vision 21 Fossil Fuel Plants  

SciTech Connect

The objective of this project was to develop an environmentally benign, inexpensive, and efficient method for separating hydrogen from gas mixtures produced during industrial processes, such as coal gasification. A family of hydrogen separation membranes was developed including single phase mixed conducting ceramics, ceramic/ceramic composites, cermet membranes, cermet membranes containing a hydrogen permeable metal, and intermediate temperature composite layered membranes. Each membrane type had different operating parameters, advantages, and disadvantages that were documented over the course of the project. Research on these membranes progressed from ceramics to cermets to intermediate temperature composite layered membranes. During this progression performance was increased from 0.01 mL x min{sup -1} x cm{sup -2} up to 423 mL x min{sup -1} x cm{sup -2}. Eltron and team membranes not only developed each membrane type, but also membrane surface catalysis and impurity tolerance, creation of thin film membranes, alternative applications such as membrane promoted alkane dehydrogenation, demonstration of scale-up testing, and complete engineering documentation including process and mechanical considerations necessary for inclusion of Eltron membranes in a full scale integrated gasification combined cycle power plant. The results of this project directly led to a new $15 million program funded by the Department of Energy. This new project will focus exclusively on scale-up of this technology as part of the FutureGen initiative.

Carl R. Evenson; Shane E. Roark

2006-03-31T23:59:59.000Z

410

Proton conducting ceramic membranes for hydrogen separation  

DOE Patents (OSTI)

A multi-phase proton conducting material comprising a proton-conducting ceramic phase and a stabilizing ceramic phase. Under the presence of a partial pressure gradient of hydrogen across the membrane or under the influence of an electrical potential, a membrane fabricated with this material selectively transports hydrogen ions through the proton conducting phase, which results in ultrahigh purity hydrogen permeation through the membrane. The stabilizing ceramic phase may be substantially structurally and chemically identical to at least one product of a reaction between the proton conducting phase and at least one expected gas under operating conditions of a membrane fabricated using the material. In a barium cerate-based proton conducting membrane, one stabilizing phase is ceria.

Elangovan, S. (South Jordan, UT); Nair, Balakrishnan G. (Sandy, UT); Small, Troy (Midvale, UT); Heck, Brian (Salt Lake City, UT)

2011-09-06T23:59:59.000Z

411

Institute for Advanced Composites Manufacturing Innovation |...  

Energy Savers (EERE)

with record-breaking fuel economy Lighter and longer wind turbine blades High pressure tanks for natural gas-fueled cars Lighter, more efficient industrial equipment In the wind...

412

Sintering behavior of lanthanide-containing glass-ceramic sealants for solid oxide fuel cells  

SciTech Connect

This article reports on the influence of different lanthanides (La, Nd, Gd and Yb) on sintering behavior of alkaline-earth aluminosilicate glass-ceramics sealants for their application in solid oxide fuel cells (SOFC). All the glasses have been prepared by melt-quench technique. The in situ follow up of sintering behavior of glass powders has been done by high temperature - environmental scanning electron microscope (HT-ESEM) and hot-stage microscope (HSM) while the crystalline phase evolution and assemblage has been analyzed by x-ray diffraction (XRD) and scanning electron microscopy (SEM). All the glass compositions exhibit a glass-in-glass phase separation followed by two stage sintering resulting in well sintered glass powder compacts after heat treatment at 850 C for 1 h. Diopside (CaMgSi{sub 2}O{sub 6}) based phases constituted the major crystalline part in glass-ceramics followed by some minor phases. The increase in lanthanide content in glasses suppressed their tendency towards devitrification, thus, resulting in glass-ceramics with high amount of residual glassy phase (50-96 wt.%) which is expected to facilitate their self-healing behavior during SOFC operation. The electrical conductivity of the investigated glass-ceramics varied between (1.19 and 7.33) x 10{sup -7} S cm{sup -1} (750-800 C), and depended on the ionic field strength of lanthanide cations. Further experimentation with respect to the long term thermal and chemical stability of residual glassy phase under SOFC operation conditions along with high temperature viscosity measurements will be required in order to elucidate the potential of these glass-ceramics as self-healing sealants.

Goel, Ashutosh; Reddy, Allu Amarnath; Pascual, Maria J.; Gremillard, Laurent; Malchere, Annie; Ferreira, Jose M.

2012-05-01T23:59:59.000Z

413

Fabrication of transparent ceramics using nanoparticles  

DOE Patents (OSTI)

A method of fabrication of a transparent ceramic using nanoparticles synthesized via organic acid complexation-combustion includes providing metal salts, dissolving said metal salts to produce an aqueous salt solution, adding an organic chelating agent to produce a complexed-metal sol, heating said complexed-metal sol to produce a gel, drying said gel to produce a powder, combusting said powder to produce nano-particles, calcining said nano-particles to produce oxide nano-particles, forming said oxide nano-particles into a green body, and sintering said green body to produce the transparent ceramic.

Cherepy, Nerine J; Tillotson, Thomas M; Kuntz, Joshua D; Payne, Stephen A

2012-09-18T23:59:59.000Z

414

Engineered nano-scale ceramic supports for PEM fuel cells  

SciTech Connect

Catalyst support durability is currently a technical barrier for commercialization of polymer electrolyte membrane (PEM) fuel cells, especially for transportation applications. Degradation and corrosion of the conventional carbon supports leads to losses in active catalyst surface area and, consequently, reduced performance. As a result, the major aim of this work is to develop support materials that interact strongly with Pt, yet sustain bulk-like catalytic activities with very highly dispersed particles. This latter aspect is key to attaining the 2015 DOE technical targets for platinum group metal (PGM) loadings (0.20 mg/cm{sup 2}). The benefits of the use of carbon-supported catalysts to drastically reduce Pt loadings from the early, conventional Pt-black technology are well known. The supported platinum catalyzed membrane approach widely used today for fabrication of membrane electrode assemblies (MEAs) was developed shortly thereafter these early reports. Of direct relevance to this present work, are the investigations into Pt particle growth in PEM fuel cells, and subsequent follow-on work showing evidence of Pt particles suspended free of the support within the catalyst layer. Further, durability work has demonstrated the detrimental effects of potential cycling on carbon corrosion and the link between electrochemical surface area and particle growth. To avoid the issues with carbon degradation altogether, it has been proposed by numerous fuel cell research groups to replace carbon supports with conductive materials that are ceramic in nature. Intrinsically, these many conductive oxides, carbides, and nitrides possess the prerequisite electronic conductivity required, and offer corrosion resistance in PEMFC environments; however, most reports indicate that obtaining sufficient surface area remains a significant barrier to obtaining desirable fuel ceU performance. Ceramic materials that exhibit high electrical conductivity and necessary stability under fuel cell conditions must also exhibit high surface area as a necessary adjunct to obtaining high Pt dispersions and Pt utilization targets. Our goal in this work is to identify new synthesis approaches together with materials that will lead to ceramic supports with high surface areas and high Pt dispersions. Several strong candidates for use as PEMFC catalyst supports include: transition metal nitrides and substoichiometric titanium oxides, which hither to now have been prepared by other researcher groups with relatively low surface areas (ca. 1-50 m{sup 2}/g typical). To achieve our goals of engineering high surface area, conductive ceramic support for utilization in PEMFCs, a multi-institutional and multi-disciplinary team with experience synthesizing and investigating these materials has been assembled. This team is headed by Los Alamos National Laboratory and includes Oak Ridge National Laboratory and the University of New Mexico. This report describes our fiscal year 2010 technical progress related to applying advanced synthetiC methods towards the development of new ceramic supports for Pt catalysts for PEM fuel cells.

Brosha, Eric L [Los Alamos National Laboratory; Blackmore, Karen J [Los Alamos National Laboratory; Burrell, Anthony K [Los Alamos National Laboratory; Henson, Neil J [Los Alamos National Laboratory; Phillips, Jonathan [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

415

Gelcasting of CRYSTAR{reg_sign} silicon carbide ceramics. CRADA final report  

SciTech Connect

This Cooperative Research and Development Agreement (CRADA) was undertaken to assess the applicability the gelcasting process for forming ceramic green bodies using Saint-Gobain/Norton Industrial Ceramics Corporation`s proprietary CRYSTAR{reg_sign} silicon carbide powder. A gelcasting process, specifically tailored to Saint-Gobain/Norton`s powder composition, was developed and used successfully to form green bodies for property evaluation. This preliminary evaluation showed that the gelcast material had characteristics and properties comparable to Norton`s baseline material. Wafer carrier molds were received from Norton for gelcasting a complex-shaped configuration with CRYSTAR{reg_sign} silicon carbide. Gelcasting experiments showed that Norton`s standard plaster of paris molds were incompatible with the gelcasting process. Mold surface treatments and the use of alternative castable mold materials were investigated, however, a successful process was not identified. The highest quality parts were cast in either glass or aluminum molds.

Nunn, S.D.; Willkens, C.A.

1998-12-31T23:59:59.000Z

416

Transport properties of lithium- lead-vanadium-telluride glass and glass ceramics  

SciTech Connect

Glasses with the chemical composition 35Li{sub 2}O-(45-x)V{sub 2}O{sub 5?}20PbO-xTeO{sub 2} (where x = 2.5, 5, 7.5, 10, 15 mol %) have prepared by conventional melt quenching method. The electrical conductivity of Li{sup +} ion conducting lead vanadium telluride glass samples has been carried out both as a function of temperature and frequency in the temperature range 503K-563K and over frequencies 40 Hz to 10 MHz. The electronic conduction has been observed in the present systems. When these samples annealed around 400°C for 2hour become the glass ceramic, which also shows increase tendency of conductivity. SEM confines glass and glass ceramic nature of the prepared samples.

Sathish, M., E-mail: sathishphy79@gmail.com [Department of Physics, GOVT first grade College, Doddaballapur-561203 (India); Eraiah, B., E-mail: eraiah@rediffmail.com [Department of Physics, Bangalore University, Bangalore-560056, India (India)

2014-04-24T23:59:59.000Z

417

Ceramic-polymer nanocomposites with increased dielectric permittivity and low dielectric loss  

SciTech Connect

The use of lead free materials in device fabrication is very essential from environmental point of view. We have synthesized the lead free ferroelectric polymer nanocomposite films with increased dielectric properties. Lead free bismuth titanate has been used as active ceramic nanofillers having crystallite size 24nm and PVDF as the polymer matrix. Ferroelectric ?-phase of the polymer composite films was confirmed by X-ray diffraction pattern. Mapping data confirms the homogeneous dispersion of ceramic particles into the polymer matrix. Frequency dependent dielectric constant increases up to 43.4 at 100Hz, whereas dielectric loss decreases with 7 wt% bismuth titanate loading. This high dielectric constant lead free ferroelectric polymer films can be used for energy density applications.

Bhardwaj, Sumit, E-mail: sumit.bhardwaj4@gmail.com; Paul, Joginder, E-mail: sumit.bhardwaj4@gmail.com [Centre for Materials Science and Engineering, National Institute of Technology, Hamirpur -177 005 (India); Raina, K. K. [School of Physics and Materials Science, Thapar University, Patiala -147 004 (India); Thakur, N. S. [Centre for Energy and Environment, National Institute of Technology, Hamirpur -177005 (India); Kumar, Ravi [Centre for Materials Science and Engineering, National Institute of Technology, Hamirpur -177 005 (India); Beant College of Engineering and Technology, Gurdaspur -143521 (India)

2014-04-24T23:59:59.000Z

418

ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS  

SciTech Connect

Eltron Research Inc., and team members, are developing an environmentally benign, inexpensive, and efficient method for separating hydrogen from gas mixtures produced during industrial processes, such as coal gasification. This project was motivated by the National Energy Technology Laboratory (NETL) Vision 21 initiative which seeks to economically eliminate environmental concerns associated with the use of fossil fuels. This objective is being pursued using dense membranes based in part on Eltron-patented ceramic materials with a demonstrated ability for proton and electron conduction. The technical goals are being addressed by modifying single-phase and composite membrane composition and microstructure to maximize proton and electron conductivity without loss of material stability. Ultimately, these materials must enable hydrogen separation at practical rates under ambient and high-pressure conditions, without deactivation in the presence of feedstream components such as carbon dioxide, water, and sulfur. During this quarter, it was demonstrated that increasing the transition metal loading in a model perovskite composition resulted in an increase in hydrogen flux. Improved flux corresponded to the emergence of additional phases in the ceramic membrane, and highest flux was achieved for a composite consisting of pseudo-cubic and rhombohedral perovskite phases. A 0.9-mm thick membrane of this material generated a hydrogen flux in excess of 0.1 mL/min/cm{sup 2}, which was approximately 35 times greater than analogs with lower transition metal levels. The dopant level and crystal structure also correlated with membrane density and coefficient of thermal expansion, but did not appear to affect grain size or shape. Additionally, preliminary ceramic-metal (cermet) composite membranes demonstrated a 10-fold increase in flux relative to analogous membranes composed of only the ceramic component. The hydrogen flux for these cermet samples corresponded to a conductivity of {approx} 10{sup -3} S/cm, which was consistent with the predicted proton conductivity of the ceramic phase. Increasing the sweep gas flow rate in test reactors was found to significantly increase hydrogen flux, as well as apparent material conductivity for all samples tested. Adding humidity to the feed gas stream produced a small increase in hydrogen flux. However, the catalyst on ceramic membrane surfaces did not affect flux, which suggested that the process was membrane-diffusion limited. Representative samples and fabrication processes were evaluated on the basis of manufacturing practicality. it was determined that optimum membrane densification occurs over a very narrow temperature range for the subject ceramics. Additionally, calcination temperatures currently employed result in powders that are difficult mill and screen. These issues must be addressed to improve large-scale fabricability.

Shane E. Roark; Tony F. Sammells; Adam E. Calihman; Lyrik Y. Pitzman; Pamela M. Van Calcar; Richard A. Mackay; Tom F. Barton; Sara L. Rolfe; Richard N. Kleiner; James E. Stephan; Tim R. Armstrong; Mike J. Holmes; Aaron L. Wagner

2001-04-30T23:59:59.000Z

419

Composite Materials under Extreme Radiation and Temperature Environments of the Next Generation Nuclear Reactors  

SciTech Connect

In the nuclear energy renaissance, driven by fission reactor concepts utilizing very high temperatures and fast neutron spectra, materials with enhanced performance that exceeds are expected to play a central role. With the operating temperatures of the Generation III reactors bringing the classical reactor materials close to their performance limits there is an urgent need to develop and qualify new alloys and composites. Efforts have been focused on the intricate relations and the high demands placed on materials at the anticipated extreme states within the next generation fusion and fission reactors which combine high radiation fluxes, elevated temperatures and aggressive environments. While nuclear reactors have been in operation for several decades, the structural materials associated with the next generation options need to endure much higher temperatures (1200 C), higher neutron doses (tens of displacements per atom, dpa), and extremely corrosive environments, which are beyond the experience on materials accumulated to-date. The most important consideration is the performance and reliability of structural materials for both in-core and out-of-core functions. While there exists a great body of nuclear materials research and operating experience/performance from fission reactors where epithermal and thermal neutrons interact with materials and alter their physio-mechanical properties, a process that is well understood by now, there are no operating or even experimental facilities that will facilitate the extreme conditions of flux and temperature anticipated and thus provide insights into the behaviour of these well understood materials. Materials, however, still need to be developed and their interaction and damage potential or lifetime to be quantified for the next generation nuclear energy. Based on material development advances, composites, and in particular ceramic composites, seem to inherently possess properties suitable for key functions within the operating envelope of both fission and fusion reactors. In advanced fission reactors composite materials are being designed in an effort to extend the life and improve the reliability of fuel rod cladding as well as structural materials. Composites are being considered for use as core internals in the next generation of gas-cooled reactors. Further, next-generation plasma-fusion reactors, such as the International Thermonuclear Experimental Reactor (ITER) will rely on the capabilities of advanced composites to safely withstand extremely high neutron fluxes while providing superior thermal shock resistance.

Simos, N.

2011-05-01T23:59:59.000Z

420

MHD oxidant intermediate temperature ceramic heater study. Final report  

SciTech Connect

The use of three types of directly fired ceramic heaters for preheating oxygen enriched air to an intermediate temperature of 1144K was investigated. The three types of ceramic heaters are: (1) a fixed bed, periodic flow ceramic brick regenerative heater (2) a ceramic pebble regenerative heater. The heater design, performance and operating characteristics under conditions in which the particulate matter is not solidified are evaluated. A comparison and overall evaluation of the three types of ceramic heaters and temperature range determination at which the particulate matter in the MHD exhaust gas is estimated to be a dry powder are presented.

Carlson, A.W.; Chait, I.L.; Saari, D.P.; Marksberry, C.L.

1981-09-01T23:59:59.000Z

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

Ceramic thermal barrier coating for rapid thermal cycling applications  

DOE Patents (OSTI)

A thermal barrier coating for metal articles subjected to rapid thermal cycling includes a metallic bond coat deposited on the metal article, at least one MCrAlY/ceramic layer deposited on the bond coat, and a ceramic top layer deposited on the MCrAlY/ceramic layer. The M in the MCrAlY material is Fe, Ni, Co, or a mixture of Ni and Co. The ceramic in the MCrAlY/ceramic layer is mullite or Al.sub.2 O.sub.3. The ceramic top layer includes a ceramic with a coefficient of thermal expansion less than about 5.4.times.10.sup.-6 .degree.C.sup.-1 and a thermal conductivity between about 1 J sec.sup.-1 m.sup.-1 .degree.C.sup.-1 and about 1.7 J sec.sup.-1 m.sup.-1 .degree.C.sup.-1.

Scharman, Alan J. (Hebron, CT); Yonushonis, Thomas M. (Columbus, IN)

1994-01-01T23:59:59.000Z

422

Golden Technologies Company, Inc. Request for An Advance Waiver of Domestic  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Golden Technologies Company, Inc. Request for An Advance Waiver of Golden Technologies Company, Inc. Request for An Advance Waiver of Domestic and Foreign Rights. January 10, 1995 Golden Technologies Company, Inc. Request for An Advance Waiver of Domestic and Foreign Rights. January 10, 1995 Golden Technologies Company contracted with Eaton to develop advanced manufacturing technology for the cost-effective production of ceramic heat engine components. Because GTC was cost sharing 50%, had experience in product commercialization, and because the technology of ceramic engine parts could have a significant positive effect on the economy, the waiver of domestic and foreign rights was granted. Golden Technologies Company, Inc. Request for An Advance Waiver of Domestic and Foreign Rights. January 10, 1995 More Documents & Publications

423

Ceramics: Brittle Materials for High Temperature Structures  

Science Journals Connector (OSTI)

...both debilitating and life-threatening. Investigators...oriented toward ceramic gas turbines 28 MARCH 1975 for vehicles...size that could be in the remaining samples. In a second...in actual or simulated gas turbine environments will be examined...

Arthur L. Robinson

1975-03-28T23:59:59.000Z

424

Oxygen Transport Ceramic Membranes Quarterly Report  

E-Print Network (OSTI)

/Reaction rates in Ion 21 Transport Membranes using Isotope Tracer and Transient Kinetic Techniques CONCLUSIONS 30Oxygen Transport Ceramic Membranes Quarterly Report January 2003 ­ March 2003 Principal Authors on the thermodynamic properties of the membrane materials are continued to develop a complete model for the membrane

Eagar, Thomas W.

425

Economic Assessment of the NIST Ceramic  

E-Print Network (OSTI)

98-3 Planning Report Economic Assessment of the NIST Ceramic Phase Diagram Program Prepared by and Economic Analysis Group February 1998 U.S Department of Commerce Technology Administration #12;#12;ECONOMIC of Standards and Technology Program Office Strategic Planning and Economic Analysis Group Prepared under

426

Ceramic fabricator quality revolution: A case study  

SciTech Connect

This case study discusses statistical process control and other quality tools in the application of continuous improvement and total quality management programs to a mature ceramic parts manufacturing operation that had been producing quality'' products for many years. By applying these tools, significant incremental improvements in process performance and product quality were achieved.

Martin, S.C. (Advanced Refractory Technologies, Inc., Buffalo, NY (United States))

1993-11-01T23:59:59.000Z

427

Evaluation of interphase properties in a cellulose fiber-reinforced polypropylene composite by nanoindentation  

E-Print Network (OSTI)

fiber and polypropylene (PP) matrix in a cellulose fiber-reinforced PP composite were investigatedEvaluation of interphase properties in a cellulose fiber-reinforced polypropylene composite of Material Science, University of Tennessee, Knoxville, TN, United States c Metals and Ceramic Division, Oak

Wang, Siqun

428

Characterization and Use of Pollen as a Biorenewable Filler for Polymer Composites  

E-Print Network (OSTI)

and Engineering. 5. Cohen, Y. NOVEL CERAMIC-POLYMER COMPOSITE MEMBRANES FOR THE SEPARATION OF HAZARDOUS LIQUIDCharacterization and Use of Pollen as a Biorenewable Filler for Polymer Composites Oluwatimilehin matrix is key for effective stress transfer between the phases and improvements in mechanical properties

Das, Suman

429

L7: Microstructure-Properties: Composites 27-301, Microstructure & Properties I  

E-Print Network (OSTI)

of crystalline Ca10(PO4)6(OH) and amorphous CaPO3. This ceramic is brittle and not particularly stiff. The matrix1 Intro Composite Applns. Properties Voigt, Reuss, Hill Anistrpy. CTE Cellular Matls. Wood L7: Microstructure-Properties: Composites Fall 2007 27-301, Microstructure & Properties I A. D. Rollett

Rollett, Anthony D.

430

Ceramic Hosts for Fission Products Immobilization  

SciTech Connect

Natural spinel, perovskite and zirconolite rank among the most leach resistant of mineral forms. They also have a strong affinity for a large number of other elements and including actinides. Specimens of natural perovskite and zirconolite were radioisotope dated and found to have survived at least 2 billion years of natural process while still remain their loading of uranium and thorium . Developers of the Synroc waste form recognized and exploited the capability of these minerals to securely immobilize TRU elements in high-level waste . However, the Synroc process requires a relatively uniform input and hot pressing equipment to produce the waste form. It is desirable to develop alternative approaches to fabricate these durable waste forms to immobilize the radioactive elements. One approach is using a high temperature process to synthesize these mineral host phases to incorporate the fission products in their crystalline structures. These mineral assemblages with immobilized fission products are then isolated in a durable high temperature glass for periods measured on a geologic time scale. This is a long term research concept and will begin with the laboratory synthesis of the pure spinel (MgAl2O4), perovskite (CaTiO3) and zirconolite (CaZrTi2O7) from their constituent oxides. High temperature furnace and/or thermal plasma will be used for the synthesis of these ceramic host phases. Nonradioactive strontium oxide will be doped into these ceramic phases to investigate the development of substitutional phases such as Mg1-xSrxAl2O4, Ca1-xSrxTiO3 and Ca1-xSrxZrTi2O7. X-ray diffraction will be used to establish the crystalline structures of the pure ceramic hosts and the substitution phases. Scanning electron microscopy and energy dispersive X-ray analysis (SEM-EDX) will be performed for product morphology and fission product surrogates distribution in the crystalline hosts. The range of strontium doping is planned to reach the full substitution of the divalent metal ions, Mg and Ca, in the ceramic host phases. The immobilization of rear earth (lanthanide series) fission products in these ceramic host phases will also be studied this year. Cerium oxide is chosen to represent the rear earth fission product for substitution studies in spinel, perovskite and zirconolite ceramic hosts. Cerium has +3 and +4 oxidation states and it can replace some of the trivalent or tetravalent host ions to produce the substitution ceramics such as MgAl2-xCexO4, CaTi1-xCexO3, CaZr1-xCexTi2O7 and CaZrTi2-xCexO7. X-ray diffraction analysis will be used to compare the crystalline structures of the pure ceramic hosts and the substitution phases. SEM-EDX analysis will be used to study the Ce distribution in the ceramic host phases. The range of cerium doping is planned to reach the full substitution of the trivalent or tetravalent ions, Al, Ti and Zr, in the ceramic host phases.

Peter C Kong

2010-07-01T23:59:59.000Z

431

Advanced Systems  

NLE Websites -- All DOE Office Websites (Extended Search)

Advanced Systems: Advanced Systems: high Performance fenestration systems Research areas: Research activities to improve the performance of windows and other fenestration products must address window systems issues as well as Glazing Materials research. LBNL activities in the area of Advanced Systems include research at both the product level and the building envelope and building systems levels. Highly insulating windows - using non structural center layers Lower cost solutions to more insulating three layer glazing systems, with the potential to turn windows in U.S. heating dominated residential applications into net-energy gainers. Highly Insulating Window Frames In collaboration with the Norwegian University of Science and Technology, we are researching the potentials for highly insulating window frames. Our initial work examines European frames with reported U-factors under 0.15 Btu/hr-ft2-F. Future research aims to analyze these designs, verify these performance levels and ensure that procedures used to calculate frame performance are accurate.

432

Summary Report: Glass-Ceramic Waste Forms for Combined Fission Products  

SciTech Connect

Glass-ceramic waste form development began in FY 2010 examining two combined waste stream options: (1) alkaline earth (CS) + lanthanide (Ln), and (2) + transition metal (TM) fission-product waste streams generated by the uranium extraction (UREX+) separations process. Glass-ceramics were successfully developed for both options however; Option 2 was selected over Option 1, at the conclusion of 2010, because Option 2 immobilized all three waste streams with only a minimal decrease in waste loading. During the first year, a series of three glass (Option 2) were fabricated that varied waste loading-WL (42, 45, and 50 mass%) at fixed molar ratios of CaO/MoO{sub 3} and B{sub 2}O{sub 3}/alkali both at 1.75. These glass-ceramics were slow cooled and characterized in terms of phase assemblage and preliminary irradiation stability. This fiscal year, further characterization was performed on the FY 2010 Option 2 glass-ceramics in terms of: static leach testing, phase analysis by transmission electron microscopy (TEM), and irradiation stability (electron and ion). Also, a new series of glass-ceramics were developed for Option 2 that varied the additives: Al{sub 2}O{sub 3} (0-6 mass%), molar ratio of CaO/MoO{sub 3} and B{sub 2}O{sub 3}/alkali (1.75 to 2.25) and waste loading (50, 55, and 60 mass%). Lastly, phase pure powellite and oxyapatite were synthesized for irradiation studies. Results of this fiscal year studies showed compositional flexibility, chemical stability, and radiation stability in the current glass-ceramic system. First, the phase assemblages and microstructure of all of the FY 2010 and 2011 glass-ceramics are very similar once subjected to the slow cool heat treatment. The phases identified in these glass-ceramics were oxyapatite, powellite, cerianite, and ln-borosilicate. This shows that variations in waste loading or additives can be accommodated without drastically changing the phase assemblage of the waste form, thus making the processing and performance characteristics of the waste form more predictable/flexible. However, in the future, the glass phase still needs to be accurately characterized to determine the effects of waste loading and additives on the glass structure. Initial investigations show a borosilicate glass phase rich in silica. Second, the normalized concentrations of elements leached from the waste form during static leach testing were all below 0.6 g/L after 28d at 90 C, by the Product Consistency Test (PCT), method B. These normalized concentrations are on par with durable waste glasses such as the Low-Activity Reference Material (LRM) glass. The release rates for the crystalline phases (oxyapatite and powellite) appear to be lower (more durable) than the glass phase based on the relatively low release rates of Mo, Ca, and Ln found in the crystalline phases compared to Na and B that are mainly observed in the glass phase. However, further static leach testing on individual crystalline phases is needed to confirm this statement. Third, Ion irradiation and In situ TEM observations suggest that these crystalline phases (such as oxyapatite, ln-borosilicate, and powellite) in silicate based glass ceramic waste forms exhibit stability to 1000 years at anticipated doses (2 x 10{sup 10}-2 x 10{sup 11} Gy). This is adequate for the short lived isotopes in the waste, which lead to a maximum cumulative dose of {approx}7 x 10{sup 9} Gy, reached after {approx}100 yrs, beyond which the dose contributions are negligible. The cumulate dose calculations are based on a glass-ceramic at WL = 50 mass%, where the fuel has a burn-up of 51GWd/MTIHM, immobilized after 5 yr decay from reactor discharge.

Crum, Jarrod V.; Riley, Brian J.; Turo, Laura A.; Tang, Ming; Kossoy, Anna

2011-09-23T23:59:59.000Z

433

ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS  

SciTech Connect

Eltron Research Inc., and team members CoorsTek, Sued Chemie, and Argonne National Laboratory are developing an environmentally benign, inexpensive, and efficient method for separating hydrogen from gas mixtures produced during industrial processes, such as coal gasification. This project was motivated by the National Energy Technology Laboratory (NETL) Vision 21 initiative which seeks to economically eliminate environmental concerns associated with the use of fossil fuels. This objective is being pursued using dense membranes based in part on Eltron-patented ceramic materials with a demonstrated ability for proton and electron conduction. The technical goals are being addressed by modifying composite membrane composition and microstructure to maximize hydrogen permeation without loss of material stability. Ultimately, these materials must enable hydrogen separation at practical rates under ambient and high-pressure conditions, without deactivation in the presence of feedstream components such as carbon dioxide, water, and sulfur. During this quarter, a composite metal membrane based on an inexpensive hydrogen permeable metal achieved permeation rates in excess of 25 mL/min/cm{sup 2}. Preliminary attempts to incorporate this metal into a cermet were successful, and a thick cermet membrane (0.83 mm) with 40 vol.% metal phase achieved a permeation rate of nearly 0.4 mL/min/cm{sup 2}. Increasing the metal phase content and decreasing membrane thickness should significantly increase permeation, while maintaining the benefits derived from cermets. Two-phase ceramic/ceramic composite membranes had low hydrogen permeability, likely due to interdiffusion of constituents between the phases. However, these materials did demonstrate high resistance to corrosion, and might be good candidates for other composite membranes. Temperature-programmed reduction measurements indicated that model cermet materials absorbed 2.5 times as much hydrogen than the pure ceramic analogs. This characteristic, in addition to higher electron conductivity, likely explains the relatively high permeation for these cermets. Incorporation of catalysts with ceramics and cermets increased hydrogen uptake by 800 to more than 900%. Finally, new high-pressure seals were developed for cermet membranes that maintained a pressure differential of 250 psi. This result indicated that the approach for high-pressure seal development could be adapted for a range of compositions. Other items discussed in this report include mechanical testing, new proton conducting ceramics, supported thin films, and alkane to olefin conversion.

Shane E. Roark; Anthony F. Sammells; Richard A. Mackay; Lyrik Y. Pitzman; Thomas A. Zirbel; Stewart R. Schesnack; Thomas F. Barton; Sara L. Rolfe; U. (Balu) Balachandran; Richard N. Kleiner; James E. Stephan; Frank E. Anderson; Aaron L. Wagner; Jon P. Wagner

2003-01-30T23:59:59.000Z

434

ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS  

SciTech Connect

Eltron Research Inc., and team members, are developing an environmentally benign, inexpensive, and efficient method for separating hydrogen from gas mixtures produced during industrial processes, such as coal gasification. This project was motivated by the National Energy Technology Laboratory (NETL) Vision 21 initiative which seeks to economically eliminate environmental concerns associated with the use of fossil fuels. This objective is being pursued using dense membranes based in part on Eltron-patented ceramic materials with a demonstrated ability for proton and electron conduction. The technical goals are being addressed by modifying single-phase and composite membrane composition and microstructure to maximize proton and electron conductivity without loss of material stability. Ultimately, these materials must enable hydrogen separation at practical rates under ambient and high-pressure conditions, without deactivation in the presence of feedstream components such as carbon dioxide, water, and sulfur. During this quarter, ceramic, cermet (ceramic/metal), and thin film membranes were prepared, characterized, and evaluated for H{sub 2} transport. For selected ceramic membrane compositions an optimum range for transition metal doping was identified, and it was determined that highest proton conductivity occurred for two-phase ceramic materials. Furthermore, a relationship between transition metal dopant atomic number and conductivity was observed. Ambipolar conductivities of {approx}6 x 10{sup -3} S/cm were achieved for these materials, and {approx} 1-mm thick membranes generated H{sub 2} transport rates as high as 0.3 mL/min/cm{sup 2}. Cermet membranes during this quarter were found to have a maximum conductivity of 3 x 10{sup -3} S/cm, which occurred at a metal phase contact of 36 vol.%. Homogeneous dense thin films were successfully prepared by tape casting and spin coating; however, there remains an unacceptably high difference in shrinkage rates between the film and support, which led to membrane instability. Further improvements in high pressure membrane seals also were achieved during this quarter, and a maximum pressure of 100 psig was attained. CoorsTek optimized many of the processing variables relevant to manufacturing scale production of ceramic H{sub 2} transport membranes, and SCI used their expertise to deposit a range of catalysts compositions onto ceramic membrane surfaces. Finally, MTI compiled relevant information regarding Vision 21 fossil fuel plant operation parameters, which will be used as a starting point for assessing the economics of incorporating a H{sub 2} separation unit.

Shane E. Roark; Tony F. Sammells; Richard A. Mackay; Adam E. Calihman; Lyrik Y. Pitzman; Tom F. Barton; Sara L. Rolfe; Richard N. Kleiner; James E. Stephan; Mike J. Holmes; Aaron L. Wagner

2001-07-30T23:59:59.000Z

435

Effect of feldspar concentrate on the chemical resistance of acid-resistant materials prepared on the basis of argillaceous materials of different chemical and mineral composition  

Science Journals Connector (OSTI)

Research shows that introduction of feldspar concentrate into the composition of ceramic mixes improves mullite crystallization, and this promotes an increase in the acid resistance of refractory materials. An in...

E. S. Abdrakhimova

2008-11-01T23:59:59.000Z

436

Abrasive wear of ZrB2-containing spark-deposited and combined coatings on titanium alloy. I. microstructure and composition of ZrB2-containing coatings  

Science Journals Connector (OSTI)

To improve the abrasive wear resistance of titanium alloys, ZrB2-containing protective coatings are deposited by electrospark alloying (ESA). As electrode materials, composite ceramics with different amounts of Z...

I. A. Podchernyaeva; A. D. Panasyuk…

2009-05-01T23:59:59.000Z

437

Teaming Partner List Available for the Innovative Composites...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

This opportunity is focused on low-cost, energy efficient manufacturing and recycling of advanced fiber-reinforced polymer composites. See the FOA for instructions on how...

438

REQUEST BY KENNAMETAL, INC.., FOR AN ADVANCE WAIVER OF DOMESTIC  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

KENNAMETAL, INC.., FOR AN ADVANCE WAIVER OF DOMESTIC KENNAMETAL, INC.., FOR AN ADVANCE WAIVER OF DOMESTIC AND FOREIGN RIGHTS IN SUBJECT INVENTIONS MADE IN THE COURSE OF OR UNDER SUBCONTRACT NO. 4000017596 UNDER DOE PRIME CONTRACT NO. DE-AC05-00OR22725; DOE WAIVER DOCKET W(A)-02-045 [ORO-775] Petitioner, Kennametal, Inc., has made a timely request for an advance waiver to worldwide rights in Subject Inventions made in the course of or under Subcontract No. 4000017596 under DOE Prime Contract No. DE-AC05-00OR22725 with UT-Battelle, Inc. The scope of this work is for the development of hot-section materials for advanced microturbines. The objective of this effort is to identify an existing structural ceramic that is being manufactured for other applications, that commensurate with the requirements of advanced microturbines, shows

439

Hydrogen production by water dissociation using ceramic membranes - annual report for FY 2010.  

SciTech Connect

The objective of this project is to develop dense ceramic membranes that can produce hydrogen via coal/coal gas-assisted water dissociation without using an external power supply or circuitry. This project grew from an effort to develop a dense ceramic membrane for separating hydrogen from gas mixtures such as those generated during coal gasification, methane partial oxidation, and water-gas shift reactions. That effort led to the development of various cermet (i.e., ceramic/metal composite) membranes that enable hydrogen production by two methods. In one method, a hydrogen transport membrane (HTM) selectively removes hydrogen from a gas mixture by transporting it through either a mixed protonic/electronic conductor or a hydrogen transport metal. In the other method, an oxygen transport membrane (OTM) generates hydrogen mixed with steam by removing oxygen that is generated through water splitting. This project focuses on the development of OTMs that efficiently produce hydrogen via the dissociation of water. Supercritical boilers offer very high-pressure steam that can be decomposed to provide pure hydrogen using OTMs. Oxygen resulting from the dissociation of steam can be used for coal gasification, enriched combustion, or synthesis gas production. Hydrogen and sequestration-ready CO{sub 2} can be produced from coal and steam by using the membrane being developed in this project. Although hydrogen can also be generated by high-temperature steam electrolysis, producing hydrogen by water splitting with a mixed-conducting membrane requires no electric power or electrical circuitry.

Balachandran, U.; Dorris, S. E.; Emerson, J. E.; Lee, T. H.; Lu, Y.; Park, C. Y.; Picciolo, J. J. (Energy Systems)

2011-03-14T23:59:59.000Z

440

Hydrogen production by water dissociation using ceramic membranes - annual report for FY 2008.  

SciTech Connect

The objective of this project is to develop dense ceramic membranes that, without using an external power supply or circuitry, can produce hydrogen via coal/coal gas-assisted water dissociation. This project grew from an effort to develop a dense ceramic membrane for separating hydrogen from gas mixtures such as those generated during coal gasification, methane partial oxidation, and water-gas shift reactions. That effort led to the development of various cermet (i.e., ceramic/metal composite) membranes that enable hydrogen production by two methods. In one method, a hydrogen transport membrane (HTM) selectively removes hydrogen from a gas mixture by transporting it through either a mixed protonic/electronic conductor or a hydrogen transport metal. In the other method, an oxygen transport membrane (OTM) generates hydrogen mixed with steam by removing oxygen that is generated through water splitting. This project focuses on the development of OTMs that efficiently produce hydrogen via the dissociation of water. Supercritical boilers offer very high-pressure steam that can be decomposed to provide pure hydrogen by means of OTMs. Oxygen resulting from the dissociation of steam can be used for coal gasification, enriched combustion, or synthesis gas production. Hydrogen and sequestration-ready CO{sub 2} can be produced from coal and steam by using the membrane being developed in this project. Although hydrogen can also be generated by high-temperature steam electrolysis, producing hydrogen by water splitting with a mixed-conducting membrane requires no electric power or electrical circuitry.

Balachandran, U.; Dorris, S. E.; Emerson, J. E.; Lee, T. H.; Lu, Y.; Park, C. Y.; Picciolo, J. J.; Energy Systems

2009-03-25T23:59:59.000Z

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

EPR and magnetic susceptibility investigation of iron-zinc-phosphate glass ceramics  

SciTech Connect

(Fe{sub 2}O{sub 3}){sub x}?(P{sub 2}O{sub 5}){sub 40}?(ZnO){sub 60?x} glass ceramics containing different concentrations of Fe{sub 2}O{sub 3} ranging from 1 to 20 mol% were obtained by heat treatment of glass samples at 650 °C for 2 h. The structural and magnetic properties of these glass ceramics were investigated by means of electron paramagnetic resonance (EPR) and magnetic susceptibility measurements. The EPR spectra of the studied samples revealed absorptions centered at g ? 2.0 and 4.3. The compositional variations of the intensity and line width of these absorption lines was interpreted in terms of the variation in Fe{sup 3+} and Fe{sup 2+} ions concentration in the glass ceramics as well as the interaction between the iron ions. The magnetic susceptibility data evidenced the presence of both Fe{sup 3+} and Fe{sup 2+} ions, with their relative content depending on the Fe{sub 2}O{sub 3} concentration. Dipolar and superexchange interactions involving iron ions were revealed depending on the iron content of the sample.

Popa, A. [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania)] [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania); Stefan, R. [Agricultural Science and Veterinary Medicine University, 3-5 Calea Manastur, 400372 Cluj-Napoca, Romania and Technical University, 28 Memorandumului, 400114 Cluj-Napoca (Romania)] [Agricultural Science and Veterinary Medicine University, 3-5 Calea Manastur, 400372 Cluj-Napoca, Romania and Technical University, 28 Memorandumului, 400114 Cluj-Napoca (Romania); Bosca, M.; Dan, V.; Pop, V.; Pascuta, P. [Technical University, 28 Memorandumului, 400114 Cluj-Napoca (Romania)] [Technical University, 28 Memorandumului, 400114 Cluj-Napoca (Romania)

2013-11-13T23:59:59.000Z

442

Fossil Energy Advanced Research and Technology Development Materials Program  

SciTech Connect

Objective of this materials program is to conduct R and D on materials for fossil energy applications with focus on longer-term and generic needs of the various fossil fuel technologies. The projects are organized according to materials research areas: (1) ceramics, (2) new alloys: iron aluminides, advanced austenitics and chromium niobium alloys, and (3) technology development and transfer. Separate abstracts have been prepared.

Cole, N.C.; Judkins, R.R. (comps.)

1992-12-01T23:59:59.000Z

443

JOM: Journal of the Minerals, Metals, and Materials Society, 2012, Vol. 62, Issue 10, pp. 1148-1157 Thermal expansion of carbon nanofiber reinforced multiscale polymer composites  

E-Print Network (OSTI)

. Hollow ceramic particle filled polymer matrix composites, called syntactic foams, have also shown nanofibers (CNFs) on the thermal expansion behavior of epoxy matrix composites and hollow particle filled. The experimental measurements show that with 10 wt.% CNF the composite has about 11.6% lower CTE than the matrix

Gupta, Nikhil

444

STATEMENT OF CONSIDERATIONS REQUEST BY PRAXAIR, INC., FOR AN ADVANCED WAIVER OF DOMESTIC AND  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

, FOR AN ADVANCED WAIVER OF DOMESTIC AND , FOR AN ADVANCED WAIVER OF DOMESTIC AND FOREIGN PATENT RIGHTS UNDER COOPERATIVE AGREEMENT NO. DE-FC36- 00G010534; W(A)-00-020; CH-1036 The Petitioner, Praxair, Inc. (hereinafter "Praxair"), has requested a waiver of domestic and foreign patent rights for all subject inventions arising from its participation under the above referenced cooperative agreement entitled "Integrated Ceramic Membrane System for H 2 Production." This cooperative agreement pertains to the development of a small-scale membrane-based hydrogen production system. The objective of this cooperative agreement is to develop a cost-effective, small-scale hydrogen plant by integration of a ceramic hydrogen transport membrane (HTM) with a ceramic oxygen transport membrane (OTM) partial oxidation reactor or an air-based partial oxidation

445

A Ceramic membrane to Recycle Caustic  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

A A Ceramic Membrane to Recycle Caustic in Low-Activity Waste Stream Processing The Office of Waste Processing is sponsoring an R&D project with Ceramatec, Inc. to develop a ceramic membrane capable of separating sodium from the Hanford Low Activity Waste (LAW) stream. The Hanford High-Level Waste (HLW) tanks must be maintained in a caustic environment to inhibit corrosion. Consequently, they contain large quantities of NaOH. Ultimately the HLW will be retrieved, separated into HLW and LAW streams, with both streams being vitrified at the Waste Treatment Plant (WTP). Prior to processing, additional NaOH will be added to the LAW stream to solubilize the alumina, preventing alumina precipitation, but further increasing the NaOH quantity. This project's goal is to separate the sodium from the LAW stream prior to vitrification which will allow the NaOH to be recycled and further

446

Reactor process using metal oxide ceramic membranes  

DOE Patents (OSTI)

A reaction vessel for use in photoelectrochemical reactions includes as its reactive surface a metal oxide porous ceramic membrane of a catalytic metal such as titanium. The reaction vessel includes a light source and a counter electrode. A provision for applying an electrical bias between the membrane and the counter electrode permits the Fermi levels of potential reaction to be favored so that certain reactions may be favored in the vessel. The electrical biasing is also useful for the cleaning of the catalytic membrane. Also disclosed is a method regenerating a porous metal oxide ceramic membrane used in a photoelectrochemical catalytic process by periodically removing the reactants and regenerating the membrane using a variety of chemical, thermal, and electrical techniques. 2 figures.

Anderson, M.A.

1994-05-03T23:59:59.000Z

447

Advanced Search  

NLE Websites -- All DOE Office Websites (Extended Search)

Publications Publications Advanced Search Most publications by Environmental Energy Technologies Division authors are searchable from this page, including peer-reviewed publications, book chapters, conference proceedings and LBNL reports. Filter Advanced Search Publications list This publications database is an ongoing project, and not all Division publications are represented here yet. For additional help see the bottom of this page. Documents Found: 4418 Title Keyword LBNL Number Author - Any - Abadie, Marc O Abbey, Chad Abdolrazaghi, Mohamad Aberg, Annika Abhyankar, Nikit Abraham, Marvin M Abshire, James B Abushakra, Bass Acevedo-Ruiz, Manuel Aceves, Salvador Ache, Hans J Ackerly, David D Ackerman, Andrew S Adamkiewicz, Gary Adams, J W Adams, Carl Adamson, Bo Addy, Nathan Addy, Susan E Aden, Nathaniel T Adesola, Bunmi Adhikari,

448

Advanced Combustion  

NLE Websites -- All DOE Office Websites (Extended Search)

Systems Systems Advanced Combustion Background Conventional coal-fired power plants utilize steam turbines to generate electricity, which operate at efficiencies of 35-37 percent. Operation at higher temperatures and pressures can lead to higher efficiencies, resulting in reduced fuel consumption and lower greenhouse gas emissions. Higher efficiency also reduces CO2 production for the same amount of energy produced, thereby facilitating a reduction in greenhouse gas emissions. When combined, oxy-combustion comes with an efficiency hit, so it will actually increase the amount of CO2 to be captured. But without so much N2 in the flue gas, it will be easier and perhaps more efficient to capture, utilize and sequester. NETL's Advanced Combustion Project and members of the NETL-Regional University

449

OPERATIONAL PERFORMANCES DEMONSTRATION OF POLYMER-CERAMIC EMBEDDED CAPACITORS FOR MMIC APPLICATIONS  

E-Print Network (OSTI)

coefficient and the thermal conductivity between the ceramic dielectric, the terminations, the solderOPERATIONAL PERFORMANCES DEMONSTRATION OF POLYMER- CERAMIC EMBEDDED CAPACITORS FOR MMIC candidates for dielectric materials applied for embedded passives are polymer- ceramic nanocomposites

Boyer, Edmond

450

Manufacture of ceramic tiles from fly ash  

DOE Patents (OSTI)

The present invention relates to a process for forming glass-ceramic tiles. Fly ash containing organic material, metal contaminants, and glass forming materials is oxidized under conditions effective to combust the organic material and partially oxidize the metallic contaminants and the glass forming materials. The oxidized glass forming materials are vitrified to form a glass melt. This glass melt is then formed into tiles containing metallic contaminants. 6 figs.

Hnat, J.G.; Mathur, A.; Simpson, J.C.

1999-08-10T23:59:59.000Z

451

Thermal and electrostrictive expansion characteristics of MLC (Multilayer Ceramic) capacitors  

SciTech Connect

We have measured by strain gauge technique, in-plane thermal expansivity (coefficient of thermal expansion) as a function of temperature and electrostrictive expansion as a function of applied DC voltage for ceramic capacitors with X7R, NPO and N1500 dielectrics. Multilayer Ceramic (MLC) capacitor materials from two commercial suppliers were evaluated. Thermal expansivities of these materials were compared to polyimide-quartz boards and alumina ceramic substrates. 4 refs., 9 figs., 1 tab.

Chanchani, R.; Hall, C.A.

1991-01-01T23:59:59.000Z

452

Method for preparing corrosion-resistant ceramic shapes  

DOE Patents (OSTI)

Ceramic shapes having impermeable tungsten coatings can be used for containing highly corrosive molten alloys and salts. The shapes are prepared by coating damp green ceramic shapes containing a small amount of yttria with a tungsten coating slip which has been adjusted to match the shrinkage rate of the green ceramic and which will fire to a theoretical density of at least 80% to provide a impermeable coating.

Arons, Richard M. (Wheaton, IL); Dusek, Joseph T. (Downers Grove, IL)

1983-09-13T23:59:59.000Z

453

STATEMENT OF CONSIDERATIONS ADVANCE CLASS WAIVER OF PATENT RIGHTS FOR  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

FOR FOR TECHNOLOGY DEVELOPED UNDER DOE FUNDING AGREEMENTS RELATING TO DOE'S CONTINUOUS FIBER CERAMICS COMPOSITE PROGRAM W(C)-92-005 In the report of the House Committee on appropriations relating to the Department of Interior and Related Agencies Appropriations Act of 1990 (Public Law 101-121), DOE was requested to develop and implement a comprehensive program for the development of continuous fiber ceramic composites (CFCC's). Accordingly, DOE, acting through its office of Industrial Programs under the Assistant Secretary for Conservation and Renewable Energy, has established and is now implementing a CFCC development program. Under the CFCC Program, DOE is selecting a number of separate teams to develop a variety of CFCC technical areas (Projects) proposed by the teams. Each of

454

dual-phase-ceramic-asu | netl.doe.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

Targets Systems Analysis Regulatory Drivers Program Plan Capture Handbook Pre-Combustion Carbon Dioxide Capture by a New Dual-Phase Ceramic Carbonate Membrane Reactor Project No.:...

455

Radiation Damage in Titanate Ceramics Used for Plutonium Immobilization  

SciTech Connect

Results from radiation damage experiments are discussed with respect to the immobilization of Pu declared excess to the weapons programs. The ceramics are titanate-based.

Strachan, Denis M.; Scheele, Randall D.; Kozelisky, Anne E.; Sell, Richard L.; Schaef, Herbert T.; O'Hara, Matthew J.; Brown, Christopher F.; Buchmiller, William C.

2002-05-01T23:59:59.000Z

456

OPTICAL AND PHYSICAL PROPERTIES OF CERAMIC CRYSTAL LASER MATERIALS.  

E-Print Network (OSTI)

??Historically ceramic crystal laser material has had disadvantages compared to single crystal laser material. However, progress has been made in the last decade and a… (more)

Simmons, Jed

2007-01-01T23:59:59.000Z

457

Implementation and application of NDE on ceramic candle filters.  

E-Print Network (OSTI)

??A nondestructive evaluation (NDE) technique has been developed to determine the deterioration and remaining life of full-size ceramic candle filters used at the Power System… (more)

Kiriakidis, Alejandro C., 1971-

2003-01-01T23:59:59.000Z

458

Method and apparatus for radio frequency ceramic sintering  

DOE Patents (OSTI)

Radio frequency energy is used to sinter ceramic materials. A coaxial waveguide resonator produces a TEM mode wave which generates a high field capacitive region in which a sample of the ceramic material is located. Frequency of the power source is kept in the range of radio frequency, and preferably between 60-80 MHz. An alternative embodiment provides a tunable radio frequency circuit which includes a series input capacitor and a parallel capacitor, with the sintered ceramic connected by an inductive lead. This arrangement permits matching of impedance over a wide range of dielectric constants, ceramic volumes, and loss tangents. 6 figures.

Hoffman, D.J.; Kimrey, H.D. Jr.

1993-11-30T23:59:59.000Z

459