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1

INVESTIGATION OF NOVEL ALLOY TiC-Ni-Ni3Al FOR SOLID OXIDE FUEL CELL INTERCONNECT APPLICATIONS  

SciTech Connect

Solid oxide fuel cell interconnect materials must meet stringent requirements. Such interconnects must operate at temperatures approaching 800 C while resisting oxidation and reduction, which can occur from the anode and cathode materials and the operating environment. They also must retain their electrical conductivity under these conditions and possess compatible coefficients of thermal expansion as the anode and cathode. Results are presented in this report for fuel cell interconnect candidate materials currently under investigation based upon nano-size titanium carbide (TiC) powders. The TiC is liquid phase sintered with either nickel (Ni) or nickel-aluminide (Ni{sub 3}Al) in varying concentrations. The oxidation resistance of the submicron grain TiC-metal materials is presented as a function weight change versus time at 700 C and 800 C for varying content of metal/intermetallic in the system. Electrical conductivity at 800 C as a function of time is also presented for TiC-Ni to demonstrate the vitality of these materials for interconnect applications. TGA studies showed that the weight gain was 0.8 mg/cm{sup 2} for TiC(30)-Ni(30wt.%) after 100 hours in wet air at 800 C and the weight gain was calculated to be 0.5205 mg/cm{sup 2} for TiC(30)- Ni(10 wt.%) after 100 hours at 700 C and 100 hours at 800 C. At room temperature the electrical conductivity was measured to be 2444 1/[ohm.cm] for TiC-Ni compositions. The electrical conductivities at 800 C in air was recorded to be 19 1/[ohm.cm] after 125 hours. Two identical samples were supplied to PNNL (Dr. Jeff Stevenson) for ASR testing during the pre-decision period and currently they are being tested there. Fabrication, oxidation resistance and electrical conductivity studies indicate that TiC-Ni-Ni{sub 3}Al ternary appears to be a very important system for the development of interconnect composition for solid oxide fuel cells.

Rasit Koc; Geoffrey Swift; Hua Xie

2005-01-25T23:59:59.000Z

2

Deformation and fracture behavior of composite structured Ti-Nb-Al-Co(-Ni) alloys  

SciTech Connect

Tensile ductility of the Ti-based composites, which consist of a ?-Ti phase surrounded by ultrafine structured intermetallics, is tunable through the control of intermetallics. The two Ti-based alloys studied exhibit similar compressive yield strength (about 1000?MPa) and strain (about 35%–40%) but show a distinct difference in their tensile plasticity. The alloy Ti{sub 71.8}Nb{sub 14.1}Ni{sub 7.4}Al{sub 6.7} fractures at the yield stress while the alloy Ti{sub 71.8}Nb{sub 14.1}Co{sub 7.4}Al{sub 6.7} exhibits about 4.5% of tensile plastic deformation. To clarify the effect of microstructure on the deformation behavior of these alloys, tensile tests were carried out in the scanning electron microscope. It is shown that the distribution as well as the type of intermetallics affects the tensile ductility of the alloys.

Okulov, I. V., E-mail: i.okulov@ifw-dresden.de; Marr, T.; Schultz, L.; Eckert, J. [IFW Dresden, Helmholtzstr. 20, D-01069 Dresden (Germany); Institut für Werkstoffwissenschaft, Technische Universität Dresden, D-01062 Dresden (Germany); Kühn, U. [IFW Dresden, Helmholtzstr. 20, D-01069 Dresden (Germany); Freudenberger, J. [IFW Dresden, Helmholtzstr. 20, D-01069 Dresden (Germany); Institut für Werkstoffwissenschaft, Technische Universität Bergakademie Freiberg, Gustav-Zeuner-Str. 5, D-09599 Freiberg (Germany); Oertel, C.-G.; Skrotzki, W. [Institut für Strukturphysik, Technische Universität Dresden, D-01062 Dresden (Germany)

2014-02-17T23:59:59.000Z

3

Electrospark deposition of Al2O3–TiB2/Ni composite-phase surface coatings on Cu–Cr–Zr alloy electrodes  

Science Journals Connector (OSTI)

Abstract To improve electrode life during the resistance spot welding of galvanized steel plates, an Al2O3–TiB2 composite coating was synthesized on the surfaces of spot-welding electrodes through an electrospark deposition process. The microstructure, elemental composition, phase structure, and mechanical properties of the coating were characterized using scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction analysis, and microhardness testing. It was found that extensive cracking occurred in the monolithic Al2O3–TiB2 coating and at the coating–electrode interface. When the Al2O3–TiB2 coating was deposited on electrodes precoated with Ni, the number of defects decreased significantly. Further, delamination did not occur, and fewer cracks were formed. The average hardness of the multilayered Al2O3–TiB2/Ni coating was approximately 2200 HV and higher than that of the monolithic Al2O3–TiB2 coating (1100 HV).

Ping Luo; Shijie Dong; Anzhuo Yangli; Shixuan Sun; Zhong Zheng; Huihu Wang

2014-01-01T23:59:59.000Z

4

Phase equilibria, formation, crystal and electronic structure of ternary compounds in Ti-Ni-Sn and Ti-Ni-Sb ternary systems  

SciTech Connect

The phase equilibria of the Ti-Ni-Sn and Ti-Ni-Sb ternary systems have been studied in the whole concentration range by means of X-ray and EPM analyses at 1073 K and 873 K, respectively. Four ternary intermetallic compounds TiNiSn (MgAgAs-type), TiNi{sub 2-x}Sn (MnCu{sub 2}Al-type), Ti{sub 2}Ni{sub 2}Sn (U{sub 2}Pt{sub 2}Sn-type), and Ti{sub 5}NiSn{sub 3} (Hf{sub 5}CuSn{sub 3}-type) are formed in Ti-Ni-Sn system at 1073 K. The TiNi{sub 2}Sn stannide is characterized by homogeneity in the range of 50-47 at% of Ni. The Ti-Ni-Sb ternary system at 873 K is characterized by formation of three ternary intermetallic compounds, Ti{sub 0.8}NiSb (MgAgAs-type), Ti{sub 5}Ni{sub 0.45}Sb{sub 2.55} (W{sub 5}Si{sub 3}-type), and Ti{sub 5}NiSb{sub 3} (Hf{sub 5}CuSn{sub 3}-type). The solubility of Ni in Ti{sub 0.8}NiSb decreases number of vacancies in Ti site up to Ti{sub 0.91}Ni{sub 1.1}Sb composition. - Graphical abstract: Isothermal section of the Ti-Ni-Sn phase diagram and DOS distribution in hypothetical TiNi{sub 1+x}Sn solid solution. Highlights: Black-Right-Pointing-Pointer Ti-Ni-Sn phase diagram was constructed at 1073 K. Black-Right-Pointing-Pointer Four ternary compounds are formed: TiNiSn, TiNi{sub 2-x}Sn, Ti{sub 2}Ni{sub 2}Sn, and Ti{sub 5}NiSn{sub 3}. Black-Right-Pointing-Pointer Three ternary compounds exist in Ti-Ni-Sb system at 873 K. Black-Right-Pointing-Pointer The TiNi{sub 2}Sb compound is absent.

Romaka, V.V., E-mail: romakav@yahoo.com [Department of Materials Engineering and Applied Physics, Lviv Polytechnic National University, Ustyyanovycha Str. 5, 79013 Lviv (Ukraine); Rogl, P. [Institut fur Physikalische Chemie der Universitat Wien, Wahringerstrabe 42, A-1090 Wien (Austria); Romaka, L.; Stadnyk, Yu. [Department of Inorganic Chemistry, Ivan Franko National University of Lviv, Kyryla and Mefodiya Str. 6, 79005 Lviv (Ukraine); Melnychenko, N.; Grytsiv, A.; Falmbigl, M. [Institut fur Physikalische Chemie der Universitat Wien, Wahringerstrabe 42, A-1090 Wien (Austria); Skryabina, N. [Perm State University, Bukireva Str. 15, 614990 Perm (Russian Federation)

2013-01-15T23:59:59.000Z

5

Nano-scratch behavior of a bulk Zr-10Al-5Ti-17.9Cu-14.6Ni amorphous alloy  

SciTech Connect

The tribological behavior of a Zr-10Al-5Ti-17.9Cu-14.6Ni (at.%) bulk amorphous alloy, in both the as-cast and annealed states, was investigated using nano-scratch tests, including ramping load scratch and multiple sliding wear techniques. The crystallization sequence of the alloy was also characterized. Mechanical properties, such as Young's modulus, hardness, friction coefficient, and tribological wear were measured. These properties were found to vary with microstructure. In general, an increase in annealing temperature results in an increase in hardness, which in turn produces a decrease in friction coefficient but an increase in wear resistance. Samples having a structure consisting of supercooled liquid matrix with dispersed nanocrystalline particles exhibit the best wear performance. (c) 2000 Materials Research Society.

Wang, J. G. [Chemistry and Materials Science, Lawrence Livermore National Laboratory, P.O. Box 808, L-350, Livermore, California 94551-9900 (United States); Choi, B. W. [Chemistry and Materials Science, Lawrence Livermore National Laboratory, P.O. Box 808, L-350, Livermore, California 94551-9900 (United States); Nieh, T. G. [Chemistry and Materials Science, Lawrence Livermore National Laboratory, P.O. Box 808, L-350, Livermore, California 94551-9900 (United States); Liu, C. T. [Metals and Ceramics Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831-6376 (United States)

2000-04-01T23:59:59.000Z

6

EFFECTS OF ION IRRADIATION ON Zr52.5Cu17.9Ni14.6Al10Ti5 (BAM-11) BULK METALLIC GLASS  

SciTech Connect

Bulk metallic glasses are intriguing candidates for nuclear applications due to their inherent amorphous structure, but their radiation response is largely unknown due to the relatively recent nature of innovations in bulk metallic glass fabrication. Here, microstructural and mechanical property evaluations have been performed on a Zr52.5Cu17.9Ni14.6Al10Ti5 bulk metallic glass (BAM-11) irradiated with 3 MeV Ni+ ions to 0.1 and 1.0 dpa at room temperature and 200 C. Nanoindentation hardness and Young s modulus both decreased by 6 to 20% in samples irradiated at room temperature, with the sample irradiated to 1.0 dpa experiencing the greatest change in mechanical properties. However, no significant changes in properties were observed in the samples irradiated at 200 C, and transmission electron microscopy showed no visible evidence of radiation damage or crystallization following ion irradiation at any of the tested conditions. These results suggest that BAM-11 bulk metallic glass may be useful for certain applications in nuclear environments.

Perez-Bergquist, Alex G [ORNL] [ORNL; Bei, Hongbin [ORNL] [ORNL; Leonard, Keith J [ORNL] [ORNL; Zhang, Yanwen [ORNL] [ORNL; Zinkle, Steven J [ORNL] [ORNL

2014-01-01T23:59:59.000Z

7

Dampfdruckmessungen und Protonenresonanzuntersuchung an Hydriden der intermetallischen Phasen Ti2(Ni, Co) und Ti2(Ni, Fe)  

Science Journals Connector (OSTI)

NMR and hydrogen equilibrium pressure measurements were performed on hydrides of the intermetallic compounds Ti2(Ni, Co) and Ti2(Ni, Fe). The following values of enthalpy ?H and entropy ?S for the formation of th...

Engelbert Tuscher; Kurt Hiebl; Helmut Bittner

1981-02-01T23:59:59.000Z

8

Microstructure and mechanical properties of Ni-based composite coatings reinforced by in situ synthesized TiB2 + TiC by laser cladding  

Science Journals Connector (OSTI)

A Ni-based composite coating reinforced by in situ synthesized TiB2...and TiC particles was fabricated on Ti6Al4V by laser cladding. An attempt was made to correlate the...2, flower-like or equiaxial TiC, and fin...

Jun Li; Xuan-jun Zhang; Hui-ping Wang…

2013-01-01T23:59:59.000Z

9

Micro artificial muscle fiber using NiTi spring for soft robotics Sangbae Kim, Elliot Hawkes, Kyujin Cho, Matthew Jolda, Joe Foley and Robert Wood  

E-Print Network (OSTI)

from shape memory alloy (NiTi) coiled springs. An enhanced spring NiTi model describes the combination of micro-coil spring, we present a novel mesh-worm prototype that utilizes bio-inspired antagonistic structure alteration, NiTi can be restructured into coil springs. Chang et al.[1], discuss the numerous

Wood, Robert

10

Fabrication and crystal line patterning of Li{sub 1.3}Al{sub 0.3}Ti{sub 1.7}(PO{sub 4}){sub 3} ion conductive glass by Ni atom heat processing method  

SciTech Connect

Li{sub 1.3}Al{sub 0.3}Ti{sub 1.7}(PO{sub 4}){sub 3} conductive crystal lines composed of closely compacted fine particles were patterned on the surface of 13.9Li{sub 2}O-8.9Al{sub 2}O{sub 3}-37.6TiO{sub 2}-38.6P{sub 2}O{sub 5}-1NiO (mol %) precursor glass by a continuous wave Yb fiber laser irradiation ({lambda}=1078 nm) using the nickel atom heat processing method. Homogeneous and smooth crystal lines with a uniform width of 30 {mu}m were obtained with a laser power of 1.3 W. The Li{sup +} ion conductivity of the laser patterned glass was about two orders of magnitude higher than that of the glass matrix due to the formation of Li{sub 1.3}Al{sub 0.3}Ti{sub 1.7}(PO{sub 4}){sub 3} conductive crystalline phase by Yb fiber laser irradiation.

Pang, Maolin; Suzuki, Ryota; Saito, Makoto; Machida, Ken-ichi; Hanzawa, Hiromasa; Nojiri, Yoshihiro; Tanase, Shigeo [Center for Advanced Science and Innovation, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Graduate School of Engineering Science, Osaka Univeristy, 1-3 Machikaneyama-cho, Toyonaka, Osaka 560-8531 (Japan); Research Institute for Ubiquitous Energy Devices, National Institute of Advanced Industrial Science and Technology (AIST), Kansai Center, 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan)

2008-01-28T23:59:59.000Z

11

Ni{sub 3}Al aluminide alloys  

SciTech Connect

This paper provides a brief review of the recent progress in research and development of Ni{sub 3}Al and its alloys. Emphasis has been placed on understanding low ductility and brittle fracture of Ni{sub 3}Al alloys at ambient and elevated temperatures. Recent studies have resulted in identifying both intrinsic and extrinsic factors governing the fracture behavior of Ni{sub 3}Al alloys. Parallel efforts on alloy design using physical metallurgy principles have led to properties for structural use. Industrial interest in these alloys is high, and examples of industrial involvement in processing and utilization of these alloys are briefly mentioned.

Liu, C.T.

1993-10-01T23:59:59.000Z

12

Nickel Alloy, Corrosion and Heat-Resistant, Sheet, Strip, and Plate 72Ni - 15.5Cr - 0.95 (Cb (Nb) + Ta) - 2.5Ti - 0.70Al - 7.0Fe Consumable Electrode, Remelted or Vacuum Induction Melted, Solution Heat Treated, Precipitation-Hardenable  

E-Print Network (OSTI)

Nickel Alloy, Corrosion and Heat-Resistant, Sheet, Strip, and Plate 72Ni - 15.5Cr - 0.95 (Cb (Nb) + Ta) - 2.5Ti - 0.70Al - 7.0Fe Consumable Electrode, Remelted or Vacuum Induction Melted, Solution Heat Treated, Precipitation-Hardenable

SAE Aerospace Standards. London

2012-01-01T23:59:59.000Z

13

Ni-Pt Silicide Formation Through Ti Mediating Layers  

SciTech Connect

With Ni1-xPtxSi, the variation in queue time between the final surface cleaning and Ni-Pt deposition represents a significant manufacturability issue. A short queue time is often difficult to maintain, leading to the formation of an oxide layer on the Si substrate prior to Ni-Pt deposition that can affect the formation of Ni1-xPtxSi and its texture. In this manuscript, it will be shown that an extended queue time prior to Ni-Pt deposition leads to morphological changes in the Ni1-xPtxSi formation sequence. A layer of Ti deposited between Ni-Pt and Si reduces the native oxide and may facilitate Ni1-xPtxSi formation. With increasing Ti thickness, the presence of metal-rich phases is gradually reduced and the formation temperature of Ni1-xPtxSi increases, suggesting a direct formation of Ni1-xPtxSi from Ni-Pt. In the presence of an interfacial oxide, an increase in formation temperature is also observed with increasing Ti interlayer thickness. When the Ti layer is sufficiently thick, the phase formation sequence becomes relatively insensitive to the presence of an interfacial oxide or extended queue time.

Besser,P.; Lavoie, C.; Ozcan, A.; Murray, C.; Strane, J.; Wong, K.; Gribelyuk, M.; Wang, Y.; Parks, C.; Jordan-Sweet, J.

2007-01-01T23:59:59.000Z

14

Surface characterization and mechanical property of TiN/Ti-coated NiTi alloy by PIIID  

E-Print Network (OSTI)

significantly reduces the friction coefficient and improves wear resistance of the NiTi alloy. © 2006 Elsevier B prosthesis, heart valve replacement and biosensors [6,7]. TiN surface coating has also been found

Zheng, Yufeng

15

Shape memory behavior of ultrafine grained NiTi and TiNiPd shape memory alloys  

E-Print Network (OSTI)

The cyclic instability in shape memory characteristics of NiTi-based shape memory alloys (SMAs), such as transformation temperatures, transformation and irrecoverable strains and transformation hysteresis upon thermal and mechanical cycling limits...

Kockar, Benat

2009-05-15T23:59:59.000Z

16

E-Print Network 3.0 - amorphous ni-ti alloys Sample Search Results  

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

044103 (6pp) doi:10.10881748-604134044103 Summary: .10881748-604134044103 Ti-TiC-TiCDLC gradient nano-composite film on a biomedical NiTi alloy Yufeng Zheng1,2, Dong...

17

Grain boundary compositon in NiAl  

SciTech Connect

The high temperature strength and oxidation resistance of many transition metal aluminides makes these intermetallic materials attractive for high temperature applications. However, these aluminides are generally brittle at low temperatures and this restricts their technological applications. However, these aluminides are generally brittle at low temperatures and this restricts their technological applications. It has been demonstrated that the addition of more than 200 ppm of boron to the L1{sub 2}-ordered Ni{sub 3}Al changes the fracture behavior from intergranular to transgranular and increases the ductility. The B2-ordered NiAl nickel aluminide is particularly attractive because of its low density and high melting temperature. This aluminide also fractures intergranularly at room temperature. However, no improvement in ductility is observed with similar boron additions even though the intergranular fracture is suppressed and there is a significant increase in the yield strength. In this paper, the results of an atom probe field ion microscopy investigation of the compositions of the grain boundaries in undoped and boron-doped NiAl are presented. The suitability of the atom probe field ion microscopy technique for the characterization of boundaries has clearly been demonstrated in many previous investigations including the characterization of boron segregation to grain boundaries and other planar features in Ni{sub 3}Al.

Miller, M.K.; Jayaram, R.; Camus, P.P. (Metals and Ceramics Div., Oak Ridge National Lab., Oak Ridge, TN (US))

1992-02-15T23:59:59.000Z

18

Electrochemistry properties of multilayer TiN/Ti coatings on NiTi alloy for cardiac occluder application  

E-Print Network (OSTI)

-elasticity, thermal shape memory, high corrosion and fatigue resistance, make NiTi alloy especially suitableTi alloy is a subject of numerous recent studies to improve the material's corrosion resistance as well,b , D.Y. Zhang e a Center for Biomedical Materials and Tissue Engineering, Academy for Advanced

Zheng, Yufeng

19

Asymmetry of radiation damage properties in Al-Ti nanolayers...  

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

reveal significant and important asymmetries in defect production with sim60% of vacancies created in Al layers compared to Ti layers within the Al-Ti multilayer system. The...

20

The Influence of Ni-Coated TiC on Laser-Deposited IN625 Metal Matrix Composites  

E-Print Network (OSTI)

The In?uence of Ni-Coated TiC on Laser-Deposited IN625 Metalwith Ni-coated and uncoated TiC reinforcement particles toand spatial distribution of TiC particles in the deposited

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ni ti al" 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

Properties of spark-deposited Ni–Cr–NiAl coatings  

Science Journals Connector (OSTI)

The structure and phase composition of sintered Ni–Cr–NiAl alloys and the kinetics of their electrospark deposition onto 45 steel are examined. It is ... shown that the mass transfer coefficient for the deposition

A. V. Paustovskii; R. A. Alfintseva…

2009-07-01T23:59:59.000Z

22

Structure and ductility of TiAl  

SciTech Connect

The effect of structural factors (grain size and grain boundary structure) and strain rate on the deformation mechanism and ductility of TiAl in the temperature range of brittle-to-ductile transition and at room temperature was systematically investigated. It has been established that it is possible to substantially affect the deformation mechanism and ductility of this intermetallic by controlling structural factors, particularly the grain size, and varying the strain rate.

Imayev, R.; Salishchev, G.; Imayev, V.; Shagiev, M.; Kuznetzov, A. [Inst. for Metals Superplasticity Problems, Ufa (Russian Federation)

1995-12-31T23:59:59.000Z

23

Combustion synthesis/quasi-isostatic pressing of TiC0.7NiTi cermets: microstructure and transformation characteristics  

E-Print Network (OSTI)

Combustion synthesis/quasi-isostatic pressing of TiC0.7­NiTi cermets: microstructure Abstract TiC0.7­NiTi cermets were produced by com- bustion synthesis followed by quasi-isostatic consolidation while the reaction products were still hot and ductile. The TiC0.7­NiTi cermets were characterized

Meyers, Marc A.

24

Formation of a Novel Ordered Ni3Al Surface Structure by Codeposition on NiAl(110)  

SciTech Connect

The formation of a new type of ordered 2D Ni3Al overlayer by low-temperature codeposition on NiAl(110) is demonstrated by kinetic Monte Carlo simulation of a multisite atomistic lattice-gas model with a precise treatment of surface diffusion kinetics. Simultaneous codeposition with 3?1 Ni?Al yields poor ordering at 300 K but well-ordered structures by ?500??K. Sequential codeposition of Ni then Al yields unmixed core-ring nanostructures at 300 K but strong intermixing and ordering by ?500??K.

Han, Yong; Unal, Baris; Evans, James W.

2012-05-23T23:59:59.000Z

25

Lanthanide Al-Ni base Ericsson cycle magnetic refrigerants  

DOE Patents (OSTI)

A magnetic refrigerant for a magnetic refrigerator using the Ericsson thermodynamic cycle comprises DyAlNi and (Gd{sub 0.54}Er{sub 0.46})AlNi alloys having a relatively constant {Delta}Tmc over a wide temperature range. 16 figs.

Gschneidner, K.A. Jr.; Takeya, Hiroyuki

1995-10-31T23:59:59.000Z

26

Lanthanide Al-Ni base Ericsson cycle magnetic refrigerants  

DOE Patents (OSTI)

A magnetic refrigerant for a magnetic refrigerator using the Ericsson thermodynamic cycle comprises DyAlNi and (Gd.sub.0.54 Er.sub.0.46)AlNi alloys having a relatively constant .DELTA.Tmc over a wide temperature range.

Gschneidner, Jr., Karl A. (Ames, IA); Takeya, Hiroyuki (Ibaraki, JP)

1995-10-31T23:59:59.000Z

27

Effect of Aging Heat Treatments on Ni52Ti48 Shape Memory Alloy  

E-Print Network (OSTI)

Ni-rich NiTi shape memory alloys (SMAs) are capable of attaining a wide range of transformation temperatures depending on the heat treatment conditions and superior thermo-mechanical cycling stability, which are desired for repeated solid...

Akin, Erhan

2011-10-21T23:59:59.000Z

28

Ni Sorption on Pyrophyllite: Evidence for the Formation of Ni-Al Hydroxide and Its Transformation into Ni-Silicate by Visible,  

E-Print Network (OSTI)

Ni Sorption on Pyrophyllite: Evidence for the Formation of Ni-Al Hydroxide and Its Transformation. Ford, K. S. Scheckel Former EXAFS studies of the sorption of Co and Ni on Al-containing clay minerals

Sparks, Donald L.

29

Formation of a Novel Ordered Ni3Al Surface Structure by Codeposition on NiAl(110)  

E-Print Network (OSTI)

The formation of a new type of ordered 2D Ni3Al overlayer by low-temperature codeposition on NiAl(110) is demonstrated by kinetic Monte Carlo simulation of a multisite atomistic lattice-gas model with a precise treatment ...

Han, Yong

30

Stable atomic structure of NiTi austenite  

SciTech Connect

Nitinol (NiTi), the most widely used shape-memory alloy, exhibits an austenite phase that has yet to be identified. The usually assumed austenitic structure is cubic B2, which has imaginary phonon modes, hence it is unstable. We suggest a stable austenitic structure that “on average” has B2 symmetry (observed by x-ray and neutron diffraction), but it exhibits finite atomic displacements from the ideal B2 sites. The proposed structure has a phonon spectrum that agrees with that from neutron scattering, has diffraction spectra in agreement with x-ray diffraction, and has an energy relative to the ground state that agrees with calorimetry data.

Zarkevich, Nikolai A [Ames Laboratory; Johnson, Duane D [Ames Laboratory

2014-08-01T23:59:59.000Z

31

E-Print Network 3.0 - al-ni-co decagonal quasicrystal Sample...  

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

Summary: of decagonal Al-Ni-Co K. Pussi Department of Electrical Engineering, Lappeenranta University of Technology, P... . EARLIER WORK ON d-Al-Ni-Co STRUCTURES Decagonal...

32

The wetting behavior of NiAl and NiPtAl on polycrystalline alumina  

SciTech Connect

In order to understand the beneficial effect of Pt on the adherence of thermally grown alumina scales, sessile drop experiments were performed to study the wetting of poly-crystalline alumina by nickel-aluminum alloys with or without platinum addition where the amount of Pt ranged from 2.4 to 10 at.%. Subsequent interfacial structure was evaluated using atomic force microscopy. Platinum addition enhances the wettability of NiAl alloys on alumina, reduces the oxide/alloy interface energy and increases the interfacial mass transport rates.

Saiz, Eduardo; Gauffier, Antoine; Saiz, Eduardo; Tomsia, Antoni P.; Hou, Peggy Y.

2007-07-01T23:59:59.000Z

33

Nanolayered CrAlTiN and multilayered CrAlTiN–AlTiN coatings for solid particle erosion protection  

Science Journals Connector (OSTI)

Abstract Applying hard coatings on airfoil surfaces is proven to be an effective approach to mitigating erosion damage to engine components. Nanolayered or multilayered coatings, because of their capability of tailoring hardness and toughness through modifications in the chemistry and architecture of layer constituents, have been explored as potential candidates for this specific application. In this study, nanolayered CrAlTiN (CrN/AlTiN) coatings with different modulation periods, along with multilayered CrAlTiN–AlTiN coatings having different number of layers and different thickness of individual layers, were fabricated, characterized and evaluated. All the coatings significantly outperformed the CrN baseline in erosion resistance, and their performance was strongly affected by the bilayer period of the nanolayered coatings or the layer architectural characteristics of multilayered coatings.

Q. Yang; R. McKellar

2015-01-01T23:59:59.000Z

34

Site preferences of indium impurity atoms in intermetallics having Al3Ti and Al3Zr crystal structures  

E-Print Network (OSTI)

Site preferences of indium impurity atoms in intermetallics having Al3Ti and Al3Zr crystal-04843 (Metals Program) and Praveen Sinha Fund for Physics Research. L12 DO22 DO23 Cu3Au Al3Ti Al3Zr #12;Outline · Indium was doped in samples of Al3V and Al3Ti (Al3Ti structure) and Al3Zr (Al3Zr structure) by arc

Collins, Gary S.

35

Structural, textural and catalytic properties of Al-, Ti-pillared clays  

SciTech Connect

Al-, Ti- and Zr-pillared clays were characterized and NiMo/Pilc`s were tested in HDS reactions. The combination of activity measurements with Moessbauer Spectroscopy and x-ray microanalysis at microscopical scale give insight in the metal phases migration during pillaring, reaction and regeneration steps. {Alpha}-Fe phase in free Fe{sub 2}O{sub 3} islands predominate together with structural Fe{sup 3+} phase, but during the catalytic reaction Fe{sup 2+} forms. Delamination of the Ti- and Zr-Clay supports, together with high Lewis acidity might enhance their catalytic properties.

Ramos-Galvan, C.E.; Dominguez, J.M.; Sandoval-Robles, G.; Castillo-Mares, A.; Nava E, N.

1996-12-31T23:59:59.000Z

36

TI--CR--AL--O thin film resistors  

DOE Patents (OSTI)

Thin films of Ti--Cr--Al--O are used as a resistor material. The films are rf sputter deposited from ceramic targets using a reactive working gas mixture of Ar and O.sub.2. Resistivity values from 10.sup.4 to 10.sup.10 Ohm-cm have been measured for Ti--Cr--Al--O film <1 .mu.m thick. The film resistivity can be discretely selected through control of the target composition and the deposition parameters. The application of Ti--Cr--Al--O as a thin film resistor has been found to be thermodynamically stable, unlike other metal-oxide films. The Ti--Cr--Al--O film can be used as a vertical or lateral resistor, for example, as a layer beneath a field emission cathode in a flat panel display; or used to control surface emissivity, for example, as a coating on an insulating material such as vertical wall supports in flat panel displays.

Jankowski, Alan F. (Livermore, CA); Schmid, Anthony P. (Solana Beach, CA)

2000-01-01T23:59:59.000Z

37

Fabrication and characterization of porous NiTi Shape Memory Alloy by elevated pressure sintering  

E-Print Network (OSTI)

have not been adequately developed. Currently, three methods are commonly used for producing porous NiTi SMAs from elemental powders. These methods include conventional sintering, Self-propagating High-temperature Synthesis (SHS), and sintering...

Vandygriff, Eric Layton

2012-06-07T23:59:59.000Z

38

Thermomechanical Cyclic Response of TiNiPd High-Temperature Shape Memory Alloys  

E-Print Network (OSTI)

TiNiPd high-temperature shape memory alloys (HTSMAs) have attracted considerable attention as potential solid-state actuators capable of operating at temperatures up to 500 °C, exhibiting excellent corrosion resistance, adequate ductility levels...

Atli, Kadri

2012-10-19T23:59:59.000Z

39

Variation of electrical resistance in superelastic NiTi for sensor applications  

E-Print Network (OSTI)

Nickel-Titanium (NiTi) is a most commonly known as a heat-activated shape memory alloy. However, the material sometimes displays a constant-temperature property called "superelasticity." A superelastic material is one which ...

Russo, Analisa

2008-01-01T23:59:59.000Z

40

Microstructure and mechanical properties of Ni sub 3 Al-based alloys reinforced with particulates  

SciTech Connect

Hot-extrusion was used to produce Ni{sub 3}Al-based alloys to which 10 vol % TiN, NbC, HfO{sub 2}, or HfN was added for reinforcement. The TiN, NbC, and HfO{sub 2} particulates produced Ni{sub 3}Al-matrix composites in which no reaction was noted at the particle-matrix interface. However, the addition of HfN resulted in extensive reaction in which the hafnium appeared to diffuse into the matrix. Microstructures of this alloy showed a complex array of phases and voids where the HfN particles are presumed to have been originally. Hot hardness, compression, and compression creep tests were preformed on specimens cut from the extruded bar of each alloy. No significant strengthening was observed for the alloys containing TiN, NbC, or HfO{sub 2}. However the HfN-containing alloy did show significant strengthening in simple compression and compression creep. This presentation will include microstructures and the results of the mechanical properties tests. 26 refs., 5 figs.

McKamey, C.G.; Carmichael, C.A.

1990-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ni ti al" 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

Dynamic recrystallization and superplasticity in TiAl  

SciTech Connect

The effect of structural factors (grain size, grain boundary structure and fraction of the second phase) on dynamic recrystallization and superplasticity in the TiAl intermetallic alloy was studied. The possibilities of the formation of submicrocrystalline structure and the abrupt decrease of the superplastic temperature were shown. It was established that the occurrence of dynamic recrystallization and superplastic flow led to the formation of homogeneous microstructure and the improvement of low-temperature ductility in TiAl.

Salishchev, G.; Imayev, R.; Imayev, V.; Shagiev, M. [Inst. for Metals Superplasticity Problems, Ufa (Russian Federation)

1995-12-31T23:59:59.000Z

42

Carbide precipitation in gamma-TiAl alloys  

SciTech Connect

Carbide precipitation in gamma-TiAl is observed and found to involve the formation of coherent, rod-shaped perovskite precipitates as a metastable transition phase. At temperatures above 750 deg C, the formation of plate-shaped H-phase particles on dislocations and grain boundaries is accompanied by dissolution of the perovskite precipitate dispersions. This temperature regime includes possible service temperatures for gamma-TiAl-based alloys. 10 refs.

Chen, S.; Beaven, P.A.; Wagner, R. (GKSS-Forschungszentrum Geesthacht GmbH, (Germany))

1992-04-01T23:59:59.000Z

43

Dielectric property of NiTiO{sub 3} doped substituted ortho-chloropolyaniline composites  

SciTech Connect

Ortho-chloropolyaniline (OCP)-NiTiO{sub 3} composites have been synthesized via in-situ polymerization of ortho-chloroaniline with various weight percentages of NiTiO{sub 3.} Fourier Transform Infrared spectroscopic studies of Ortho-chloropolyaniline and its composites indicated the formation of composites as a result of Vander Waal's interaction between OCP and NiTiO{sub 3} particles. Surface morphology of OCP and OCP-NiTiO{sub 3} composites were studied using Scanning Electron Microscope (SEM). The SEM micrographs indicated a modified morphology after the composite formation. Dielectric properties and electric modulus of OCP and OCP-NiTiO{sub 3} composites have been investigated in the frequency range of 50 Hz – 5 MHz. It has been noticed that electrical resistance decreases with increase in weight percentage of NiTiO{sub 3} particles in polymer matrix as well as with applied frequency. The display of semicircular arcs in Cole-Cole plots indicates the formation of series resistor and capacitor in network causing a decrease in the relaxation time and as a result conductivity enhances in these composites. The facile and cost effective synthesis process and excellent dielectric and conductivity response of these materials makes them promising materials for practical applications.

Lakshmi, Mohana; Faisal, Muhammad [Department of Physics, PES Institute of Technology, BSC, Bangalore- 560100 (India)] [Department of Physics, PES Institute of Technology, BSC, Bangalore- 560100 (India); Roy, Aashish S. [Department of Materials Science, Gulbarga University, Gulbarga-585106, Karnataka (India)] [Department of Materials Science, Gulbarga University, Gulbarga-585106, Karnataka (India); Khasim, Syed, E-mail: syed.pes@gmail.com [Department of Physics, PES Institute of Technology, BSC, Bangalore- 560100 (India) [Department of Physics, PES Institute of Technology, BSC, Bangalore- 560100 (India); Department of Physics, University of Tabuk-71491 (Saudi Arabia); Sajjan, K. C. [Department of Physics, Veerashaiva College, Bellary - 583 104, Karnataka (India)] [Department of Physics, Veerashaiva College, Bellary - 583 104, Karnataka (India); Revanasiddappa, M. [Department of Chemistry, PES Institute of Technology, BSC, Bangalore - 560100 (India)] [Department of Chemistry, PES Institute of Technology, BSC, Bangalore - 560100 (India)

2013-11-15T23:59:59.000Z

44

Laser Cladding of TiAl Intermetallic Alloy on Ti6Al4V -Process Optimization and Properties  

Science Journals Connector (OSTI)

Abstract In order to improve Ti6Al4V high-temperature resistance and its tribological properties, the deposition of TiAl intermetallic (Ti-48Al-2Cr-2Nb) coating on a Ti6Al4V substrate by coaxial laser cladding has been investigated. Laser cladding by powder injection is an emerging laser material processing technique that allows the deposition of thick protective coatings on substrates,using a high power laser beam as heat source. Laser cladding is a multiple-parameter-dependent process. The main process parameters involved (laser power, powder feeding rate, scanning speed and preheating temperature) has been optimized. The microstructure and geometrical quantities (clad area and dilution) of the coating was characterized by optical microscopy and scanning electron microscopy (SEM). In addition the cooling rate of the clad during the process was measured by a dual-color pyrometer. This result has been related to defectology and mechanical coating properties.

B. Cárcel; A. Serrano; J. Zambrano; V. Amigó; A.C. Cárcel

2014-01-01T23:59:59.000Z

45

Directional solidification studies in Ni-Al alloys  

SciTech Connect

Three solid phases are involved in the phase equilibria of the intermetallic compound Ni{sub 3}Al near its melting point, {beta}, {gamma}{prime}(Ni{sub 3}Al), and {gamma}. The generally-accepted phase diagram involves a eutectic reaction between {beta}{prime} and {gamma}, but some recent studies agree with an older diagram due to Schramm, which has a eutectic reaction between the {beta} and {gamma}{prime} phases. The phase equilibria near Ni{sub 3}Al compositions was evaluated using quenched directional solidification experiments, that preserve the microstructures tonned at the solidification front, and using diffusion couple experiments. These experiments show that eutectic forms between {beta} and {gamma}{prime} phases, as in the Schramm diagram. Growth and phase transformations of these three phases are also studied in the directional solidification experiments. Microstructure analysis shows that etching of Ni{sub 3}Al({gamma}{prime}) is very sensitive to small composition variations and crystallographic orientation changes. The eutectic solidification study confirms that the equilibrium eutectic is {gamma}{prime}+{beta}, and that the metastable {gamma}+{beta} eutectic might be also produced in this system according to the impurities, solidification rates, and composition variations.

Lee, Je-hyun

1993-05-01T23:59:59.000Z

46

Metallic glass alloys of Zr, Ti, Cu and Ni  

DOE Patents (OSTI)

At least quaternary alloys form metallic glass upon cooling below the glass transition temperature at a rate less than 10.sup.3 K/s. Such alloys comprise titanium from 19 to 41 atomic percent, an early transition metal (ETM) from 4 to 21 atomic percent and copper plus a late transition metal (LTM) from 49 to 64 atomic percent. The ETM comprises zirconium and/or hafnium. The LTM comprises cobalt and/or nickel. The composition is further constrained such that the product of the copper plus LTM times the atomic proportion of LTM relative to the copper is from 2 to 14. The atomic percentage of ETM is less than 10 when the atomic percentage of titanium is as high as 41, and may be as large as 21 when the atomic percentage of titanium is as low as 24. Furthermore, when the total of copper and LTM are low, the amount of LTM present must be further limited. Another group of glass forming alloys has the formula (ETM.sub.1-x Ti.sub.x).sub.a Cu.sub.b (Ni.sub.1-y Co.sub.y).sub.c wherein x is from 0.1 to 0.3, y.cndot.c is from 0 to 18, a is from 47 to 67, b is from 8 to 42, and c is from 4 to 37. This definition of the alloys has additional constraints on the range of copper content, b.

Lin, Xianghong (Pasadena, CA); Peker, Atakan (Pasadena, CA); Johnson, William L. (Pasadena, CA)

1997-01-01T23:59:59.000Z

47

First-principles investigations of Ni3Al(111) and NiAl(110) surfaces at metal dusting conditions  

SciTech Connect

We investigate the structure and surface composition of the {gamma}{prime}-Ni{sub 3}Al(111) and {beta}-NiAl(110) alloy surfaces at conditions relevant for metal dusting corrosion related to catalytic steam reforming of natural gas. In regular service as protective coatings, nickel-aluminum alloys are protected by an oxide scale, but in case of oxide scale spallation, the alloy surface may be directly exposed to the reactive gas environment and vulnerable to metal dusting. By means of density functional theory and thermochemical calculations for both the Ni{sub 3}Al and NiAl surfaces, the conditions under which CO and OH adsorption is to be expected and under which it is inhibited, are mapped out. Because CO and OH are regarded as precursors for nucleating graphite or oxide on the surfaces, phase diagrams for the surfaces provide a simple description of their stability. Specifically, this study shows how the CO and OH coverages depend on the steam to carbon ratio (S/C) in the gas and thereby provide a ranking of the carbon limits on the different surface phases.

Saadi, Souheil

2011-03-01T23:59:59.000Z

48

On the development of high quality NiTi shape memory and pseudoelastic parts by additive manufacturing  

Science Journals Connector (OSTI)

Additive manufacturing provides an attractive processing method for nickel?titanium (NiTi) shape memory and pseudoelastic parts. In this paper, we show how the additive manufacturing process affects structural and functional properties of additively manufactured NiTi and how the process parameter set-up can be optimized to produce high quality NiTi parts and components. Comparisons of shape recovery due to shape memory and pseudoelasticity in additively manufactured and commercial NiTi exhibit promising potential for this innovative processing method.

Christoph Haberland; Mohammad Elahinia; Jason M Walker; Horst Meier; Jan Frenzel

2014-01-01T23:59:59.000Z

49

[TiII] and [NiII] emission from the strontium filament of eta Carinae  

E-Print Network (OSTI)

We study the nature of the [TiII] and [NiII] emission from the so-called strontium filament found in the ejecta of eta Carinae. To this purpose we employ multilevel models of the TiII and NiII systems which are used to investigate the physical condition of the filament and the excitation mechanisms of the observed lines. For the TiII ion, for which no atomic data was previously available, we carry out ab initio calculations of radiative transition rates and electron impact excitation rate coefficients. It is found that the observed spectrum is consistent with the lines being excited in a mostly neutral region with an electron density of the order of $10^7$ cm$^{-3}$ and a temperature around 6000 K. In analyzing three observations with different slit orientations recorded between March~2000 and November~2001 we find line ratios that change among various observations, in a way consistent with changes of up to an order of magnitude in the strength of the continuum radiation field. These changes result from different samplings of the extended filament, due to the different slit orientations used for each observation, and yield clues on the spatial extent and optical depth of the filament. The observed emission indicates a large Ti/Ni abundance ratio relative to solar abundances. It is suggested that the observed high Ti/Ni ratio in gas is caused by dust-gas fractionation processes and does not reflect the absolute Ti/Ni ratio in the ejecta of \\etacar. We study the condensation chemistry of Ti, Ni and Fe within the filament and suggest that the observed gas phase overabundance of Ti

M. A. Bautista; H. Hartman; T. R. Gull; N. Smith; K. Lodders

2006-06-12T23:59:59.000Z

50

Compton Profile Study of Intermetallic Ti{sub 3}Al  

SciTech Connect

The Compton scattering measurement on intermetallic alloy Ti{sub 3}Al is reported in this work. The measurement is made using 59.54 keV gamma-rays from Am{sup 241} source. Theoretical calculation of Compton profile is also performed employing CRYSTAL code within the framework of density functional theory to compare with the measurement. The theoretical profile of the alloy is also synthesized following the superposition model taking the published Compton profiles of elemental solids from the APW method. The experimental study of charge transfer in the alloys has also been done by performing the experimental Compton profile measurements on Ti and Al following the superposition model and charge transfer from Al to Ti is clearly seen on the alloy formation.

Vyas, V.; Sharma, G. [Department of Physics, Banasthali University, Banasthali-304022 (India); Mishra, M. C.; Sharma, B. K. [Department of Physics, University of Rajasthan, Jaipur-302004 (India); Joshi, K. B. [Department of Physics, University College of Science, M.L.Sukhadia University, Udaipur-313 002 (India)

2011-10-20T23:59:59.000Z

51

Investigation of the reaction zone between TiAl and Mo  

SciTech Connect

Pure Mo was incorporated in TiAl matrix via two different routes: (1) hot pressing of alternately sandwiched Ti-Al sheets and Mo foils; and (2) coextrusion and heat treatment of Ti-Al green compact and Mo rod. The reaction zone between TiAl and Mo is found to contain two intermetallic phases: {beta}-(Mo,Ti)Al and {rho}-(Mo,Ti){sub 3}Al. The {beta}-{rho} boundary is incoherent, whereas the TiAl-{beta} and {rho}-Mo boundaries are semicoherent. The reaction zone grows with increasing heat-treatment time in a parabolic form. The incorporated Mo exhibits lower hardness than the TiAl matrix, implying that ductilizing and toughening of TiAl by introducing Mo as a ductile reinforcement are possible.

Hsu, F.Y.; Klaar, H.J. [Aachen Univ. of Technology (Germany); Wang, G.X. [Zhejiang Univ., Hangzhou (China). Dept. of Materials Science and Engineering; Pirwitz, F. [GKSS Research Center, Geesthacht (Germany). Inst. for Materials Research

1996-08-01T23:59:59.000Z

52

Textures and plastic anisotropy in gamma-TiAl  

SciTech Connect

Specimens of a Ti-36 wt pct Al alloy consisting primarily of gamma TiAl were deformed in compression at 450 C and in rolling at 1050 C. The textures of the deformed specimens were measured and analyzed in terms of orientation distribution functions. After hot rolling, the texture is strongly influenced by recrystallization and shows a cube-like component with an alignment of the c-axis with the transverse direction. The measured compression textures are compared with those simulated on the basis of the Taylor theory of polycrystal deformation. 36 refs.

Hartig, C.H.; Fang, X.F.; Mecking, H.; Dahms, M. (Hamburg, Technische Universitaet, (Germany) GKSS-Forschungszentrum Geesthacht GmbH, (Germany))

1992-08-01T23:59:59.000Z

53

TiB2/Ni coatings on surface of copper alloy electrode prepared by electrospark deposition  

Science Journals Connector (OSTI)

In order to improve the lifespan of spot-welding electrodes used for welding zinc coated steel sheets, titanium diboride was deposited onto their surface after precoating nickel as an intermediate layer. The microstructures and phase compositions of TiB2 and Ni coatings were characterized by SEM and XRD. The coating hardness was measured using a microhardness tester. The results indicate that a satisfactory TiB2 coating is obtained as a result of the intermediate nickel layer acting as a good binder between the TiB2 coating and the copper alloy substrate. Owing to its capacity of deforming, the precoated nickel layer is dense and crack free, while cracks and pores are observed in the TiB2 coating. The hardness of the TiB2/Ni coating decreases with the increase of voltage and capacitance because of the diffusion of copper and nickel and the oxidation of the coating materials. Because of the good thermal and electrical conductivities and high hardness properties of TiB2, the deformation of the electrode with TiB2/Ni coating is reduced and its spot-welding life is by far prolonged than that of the uncoated one.

Cheng LUO; Xiang XIONG; Shi-jie DONG

2011-01-01T23:59:59.000Z

54

Site-Dependent Activity of Atomic Ti Catalysts in Al-Based Hydrogen Storage Materials  

E-Print Network (OSTI)

Site-Dependent Activity of Atomic Ti Catalysts in Al-Based Hydrogen Storage Materials Abdullah Al storage processes. Here we analyze the role of atomic Ti catalysts in the hydrogenation of Al-based hydrogen storage materials. We show that Ti atoms near the Al surface activate gas-phase H2, a key step

Ciobanu, Cristian

55

Kinetics of Mixed Ni-Al Precipitate Formation on a Soil Clay Fraction  

E-Print Network (OSTI)

Kinetics of Mixed Ni-Al Precipitate Formation on a Soil Clay Fraction D A R R Y L R . R O B E R Management Laboratory, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland The kinetics of mixed Ni-Al Ni- Al LDH formation. The initial Ni concentration was 3 mM with a solid/solution ratio of 10 g L-1

Sparks, Donald L.

56

Topotaxial growth of Ti{sub 2}AlN by solid state reaction in AlN/Ti(0001) multilayer thin films  

SciTech Connect

The formation of Ti{sub 2}AlN by solid state reaction between layers of wurtzite-AlN and {alpha}-Ti was characterized by in situ x-ray scattering. The sequential deposition of these layers by dual magnetron sputtering onto Al{sub 2}O{sub 3}(0001) at 200 deg. C yielded smooth, heteroepitaxial (0001) oriented films, with abrupt AlN/Ti interfaces as shown by x-ray reflectivity and Rutherford backscattering spectroscopy. Annealing at 400 deg. C led to AlN decomposition and diffusion of released Al and N into the Ti layers, with formation of Ti{sub 3}AlN. Further annealing at 500 deg. C resulted in a phase transformation into Ti{sub 2}AlN(0001) after only 5 min.

Hoeglund, C.; Beckers, M.; Schell, N.; Borany, J. v.; Birch, J.; Hultman, L. [Thin Film Physics Division, Department of Physics, Chemistry and Biology (IFM), Linkoeping University, S-581 83 Linkoeping (Sweden); GKSS Research Center Geesthacht, Max-Planck-Str. 1, D-21502 Geesthacht (Germany); Institute of Ion Beam Physics and Materials Research, Forschungszentrum Dresden-Rossendorf, P.O. Box 510119, D-01314 Dresden (Germany); Thin Film Physics Division, Department of Physics, Chemistry and Biology (IFM), Linkoeping University, S-581 83 Linkoeping (Sweden)

2007-04-23T23:59:59.000Z

57

Correlation between corrosion performance and surface wettability in ZrTiCuNiBe bulk metallic glasses  

E-Print Network (OSTI)

Correlation between corrosion performance and surface wettability in ZrTiCuNiBe bulk metallic June 2010 The corrosion properties of two Zr-based bulk metallic glass, Zr41Ti14Cu12Ni10Be23 LM1 and Zr potential, LM1b showed superior corrosion resistance to LM1. Under identical sample preparation and testing

Zheng, Yufeng

58

Thermal stability and oxidation resistance of TiCrAlYO coatings...  

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

stability and oxidation resistance of TiCrAlYO coatings on SS430 for solid oxide fuel cell interconnect applications. Thermal stability and oxidation resistance of TiCrAlYO...

59

Vacancy-Vacancy Interactions in NiAl Matthew O. Zacate and Gary S. Collins  

E-Print Network (OSTI)

Vacancy-Vacancy Interactions in NiAl Matthew O. Zacate and Gary S. Collins Department of Physics, Washington State University, Pullman, WA 99164, USA Keywords: point defect, vacancy, defect interaction, intermetallic compound, perturbed angular correlation, PAC, NiAl Abstract. Interactions between Ni vacancies

Collins, Gary S.

60

IEEE TRANSACTIONS ON MAGNETICS, VOL. 38, NO. 4, JULY 2002 1803 New Ni5Al3 Underlayer for Longitudinal  

E-Print Network (OSTI)

IEEE TRANSACTIONS ON MAGNETICS, VOL. 38, NO. 4, JULY 2002 1803 New Ni5Al3 Underlayer--We describe a new Ni5Al3 underlayer for high-den- sity longitudinal magnetic recording. The Ni5Al3 underlayer has the FCC derivative Ga3Pt5 structure. The Ni5Al3 (221) plane has good lattice match with the Co

Laughlin, David E.

Note: This page contains sample records for the topic "ni ti al" 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

Development and Characterization of Hard and Wear Resistant MMC Coating on Ti-6Al-4V Substrate by Laser Cladding  

Science Journals Connector (OSTI)

Abstract Ti-6Al-4V, due to its high specific strength and resistance to corrosion, is one of the highly useful materials in aerospace, automobile and chemical industries. Poor hardness and wear resistance properties restrict its further applications. So surface modification of Ti-6Al-4V is necessary surface to enhance its tribological properties. Multi-phase and multi component coating development is one of the present research trends in surface engineering arena. In the present study it was attempted to develop a multi-component coating by laser cladding process using a pre-placed powder mixture containing Ni5Al (50 vol%) + hBN (10 vol%) + B4C (20 vol%) + SiC (20 vol%) on substrate of Ti-6Al-4V to improve its tribological performance. A nano-structured coating was formed with micro hardness (780 HV0.05). X-ray diffraction (XRD) identified the presence of compounds like TiC, BN, TiB2, SiC, and intermetallics of Ni-Ti in the coating. The wear behaviour of the composite coating was assessed by ball on disc type wear and friction monitor at 10 N load at 300 RPM taking a track diameter of 5 mm. Specific wear rate and coefficient of friction (?) were found to vary from 0.6E-12 to 2.2E-12 m3/N-m and from 0.15 to 0.45, respectively, due to rubbing of coated surface against tungsten carbide ball. The microstructure was explored by Scanning Electron Microscopy (SEM).

Mandeep Dhanda; Barun Haldar; P. Saha

2014-01-01T23:59:59.000Z

62

An Investigation into the evolution of damage and residual stresses in Ti6Al4V-Al?Ti metal intermetallic laminate (MIL) composites  

E-Print Network (OSTI)

good creep resistance, and relatively low material density.strengthened materials are toughened since the resistance toresistance of interfaces in NiAl/Mo model laminates, Materials

Li, Tiezheng

2006-01-01T23:59:59.000Z

63

EFFECT OF AGING ON THE PHASE TRANSFORMATION AND MECHANICAL BEHAVIOR OF Ti36Ni49Hf15 HIGH  

E-Print Network (OSTI)

and Engineering, Harbin Institute of Technology, Harbin 150001, People's Republic of China (Received August 19 the microstructure, transformation temperature, mechanical properties and shape memory effects (SMEs) for Ti36Ni49Hf

Zheng, Yufeng

64

A Study of Strain-Induced Phase Transformations in TiNi Alloy by Electric Resistance Method  

Science Journals Connector (OSTI)

It is generally recognized that the shape memory effect (SME) is associated the interaction of stress with thermoelastic martensitic transformation [1]. The phase transformations in TiNi alloy was reported to occ...

Yuan-Ti Muang; Li-Lin Lu; Lai-Zhi Zou…

1988-01-01T23:59:59.000Z

65

Interface control of ferroelectricity in LaNiO{sub 3}-BaTiO{sub 3} superlattices  

SciTech Connect

LaNiO{sub 3}-BaTiO{sub 3} superlattices with different types of interfaces are studied from first-principles density-functional theory. It is revealed that the ferroelectricity in the superlattice with (NiO{sub 2}){sup ?}/(BaO){sup 0} interfaces is enhanced from that of the superlattice with (LaO){sup +}/(TiO{sub 2}){sup 0} interfaces. The origin lies at the polar discontinuity at the interface, which makes the holes localized within the (NiO{sub 2}){sup ?}/(BaO){sup 0} interface, but drives a penetration of electrons into BaTiO{sub 3} component near (LaO){sup +}/(TiO{sub 2}){sup 0} interface. Our calculations demonstrate an effective avenue to the robust ferroelectricity in BaTiO{sub 3} ultrathin films.

Wu, Yin-Zhong, E-mail: yzwu@cslg.edu.cn [Jiangsu Laboratory of Advanced Functional Materials and Physics Department, Changshu Institute of Technology, Changshu 215500 (China); School of Mathematics and Physics, Suzhou University of Science and Technology, Suzhou 215009 (China); Lu, Hai-Shuang; Cai, Tian-Yi; Ju, Sheng, E-mail: jusheng@suda.edu.cn [Department of Physics and Jiangsu Key Laboratory of Thin Films, Soochow University, Suzhou 215006 (China)

2014-08-15T23:59:59.000Z

66

High Temperature coatings based on {beta}-NiAI  

SciTech Connect

High temperature alloys are reviewed, focusing on current superalloys and their coatings. The synthesis, characerization, and oxidation performance of a NiAl–TiB{sub 2} composite are explained. A novel coating process for Mo–Ni–Al alloys for improved oxidation performance is examined. The cyclic oxidation performance of coated and uncoated Mo–Ni–Al alloys is discussed.

Severs, Kevin

2012-07-10T23:59:59.000Z

67

Superplastic foaming of titanium and Ti-6Al-4V  

SciTech Connect

Solid-state foaming of metals can be achieved by hot-isostatic pressing of powders in presence of argon followed by expansion of the resulting high-pressure argon bubbles at ambient pressure and elevated temperature. This foaming technique was first demonstrated by Kearns et al. for Ti-6Al-4V, but is limited by its low creep rate and ductility, which lead to early cell wall fracture. The authors address these issues by performing the foaming step under superplastic conditions. Rather than using microstructural superplasticity (requiring fine grains which are difficult to achieve in porous powder-metallurgy materials), they used transformation superplasticity, which occurs at all grain sizes by biasing with a deviatoric stress (from the pore pressure) of internal stresses (from the allotropic mismatch during thermal cycling about the allotropic temperature range). As compared to control experiments performed under isothermal creep conditions, superplastic foaming under temperature cycling of unalloyed titanium and alloyed Ti-6Al-4V led to a significantly higher pore volume fraction and higher foaming rate.

Dunand, D.C. [Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering; Teisen, J. [Swiss Federal Inst. of Tech., Zuerich (Switzerland). Dept. of Materials

1998-12-31T23:59:59.000Z

68

Glass Forming Ability in Pr-(Cu, Ni)-Al Alloys  

E-Print Network (OSTI)

Glass forming ability (GFA) in the Pr-rich Pr-(Cu, Ni)-Al alloys at or near the eutectic points was systematically studied. It was found that the GFA in the pseudo-ternary alloys of Pr-(Cu, Ni)-Al is higher than that of ...

Zhang, Yong

69

On elongated stacking fault loops in TiAl  

SciTech Connect

Depending upon strain, load orientation, alloy composition and test temperature, the deformation microstructure of TiAl contains a varied density of stacking faults ribbons. The presence of these ribbons is correlated with that of superdislocations with 1/2{l_angle}112[square bracket] Burgers vector. They are elongated along any of the {l_angle}011[square bracket] directions. The present paper focuses on their formation mechanism, especially on the reasons which make that such dipolar defects, though intrinsically unstable, tend to exhibit a reasonably constant width.

Hug, G.; Veyssiere, P. [CNRS-ONERA, Chatillon (France)

1995-12-31T23:59:59.000Z

70

Critical cooling rate and thermal stability of Zr--Ti--Cu--Ni--Be alloys  

SciTech Connect

The critical cooling rate as well as the thermal stability are measured for a series of alloys in the Zr--Ti--Cu--Ni--Be system. Upon cooling from the molten state with different rates, alloys with compositions ranging along a tie line from (Zr{sub 70}Ti{sub 30}){sub 55}(Ni{sub 39}Cu{sub 61}){sub 25}Be{sub 20} to (Zr{sub 85}Ti{sub 15}){sub 55}(Ni{sub 57}Cu{sub 43}){sub 22.5}Be{sub 27.5} show a continuous increase in the critical cooling rate to suppress crystallization. In contrast, thermal analysis of the same alloys shows that the undercooled liquid region, the temperature difference between the glass transition temperature and the crystallization temperature, is largest for some compositions midway between the two endpoints, revealing that glass forming ability does not correlate with thermal stability. The relationship between the composition-dependent glass forming ability and thermal stability is discussed with reference to a chemical decomposition process.

Waniuk, Theodore A.; Schroers, Jan; Johnson, William L.

2001-02-26T23:59:59.000Z

71

Microstructure and magnetoelectric properties in Pb,,ZrxTi1-x...O3Ni composite ferroic films  

E-Print Network (OSTI)

Microstructure and magnetoelectric properties in Pb,,ZrxTi1-x...O3­Ni composite ferroic films 15213 Presented on 31 October 2005; published online 19 April 2006 Ferroic composite thin films composite films grown on SiO2/Si substrates at 650 °C, a perovskite structure was obtained when the Ni

Laughlin, David E.

72

Overall photocatalytic water splitting with NiOxSrTiO3 a revised Troy K. Townsend,a  

E-Print Network (OSTI)

catalysts assumes water oxidation to occur at the early transition metal oxide and water reduction at NiOx­La : KTaO3, and many layered perovskites. Introduction Splitting water into hydrogen and oxygen gas usingOverall photocatalytic water splitting with NiOx­SrTiO3 ­ a revised mechanism Troy K. Townsend

Osterloh, Frank

73

Formation and Stability of Ni-Al Hydroxide Phases in Soils  

SciTech Connect

The formation of mixed metal-aluminum hydroxide surface precipitates is a potentially significant uptake route for trace metals (including Co, Ni, and Zn) in environmental systems. This paper investigates the effect of mixed Ni-Al hydroxide precipitate formation and aging on Ni solubility and bioavailability in laboratory contaminated soils. Two Delaware agricultural soils were reacted with a 3 mM Ni solution for 12 months at pH's above and below the threshold for mixed Ni-Al hydroxide formation. Ni speciation was determined at 1, 6, and 12 months using X-ray absorption spectroscopy (XAS). Precipitate solubility was examined through desorption experiments using HNO{sub 3} and EDTA as desorbing agents, whereas metal bioavailability was assessed using a Ni-specific bacterial biosensor. For both soils, the formation of Ni-Al hydroxide surface precipitates resulted in a reduction in the fraction of desorbed and bioavailable Ni. However, precipitate dissolution was greater, particularly with EDTA, than in published studies on isolated soil clay fractions, and less affected by aging processes. These results suggest that mixed Ni-Al hydroxide phases forming in real world environments may be both longer-lasting and more susceptible to ligand-promoted dissolution than previously expected.

Peltier, E.; Van Der Lelie, D; Sparks, D

2010-01-01T23:59:59.000Z

74

Sol-gel-derived NiO/NiAl{sub 2}O{sub 4} oxygen carriers for chemical-looping combustion by coal char  

SciTech Connect

This paper focuses on the investigation of Ni-based oxygen carriers for CLC by coal char. First, Al(OC{sub 3}H{sub 7}){sub 3} and Ni(NO{sub 3}){sub 2} are selected as the main raw materials to prepare sol-gel-derived NiO/NiAl{sub 2}O{sub 4} oxygen carriers. The oxygen carrier with a mass content of 60% NiO, a sintering temperature of 1300{sup o}C, and a sintering time of 6 h performs comparatively well. Second, the reduction reaction of the NiO/NiAl{sub 2}O{sub 4} oxygen carriers with char and the circular reduction/oxidation reactions of the NiO/NiAl{sub 2}O{sub 4} oxygen carriers with char/air or hydrogen/air are carried out in a thermogravimetric analysis (TGA) instrument to investigate the reactivities and chemical life of the prepared NiO/NiAl{sub 2}O{sub 4} oxygen carriers. The experimental results show that (a) when the TGA temperature is higher than 850{sup o}C, NiO/NiAl{sub 2}O{sub 4} starts to react with coal char rapidly, which indicates that CLC of coal char using NiO/NiAl{sub 2}O{sub 4} as oxygen carriers is a feasible technology of energy utilization in principle; (b) NiO/NiAl{sub 2}O{sub 4}, which maintains its activity over single-cycle reduction/oxidation reactions with char/air or multiple-cycle reduction/oxidation reactions with hydrogen/air, exhibits extremely good recyclablity; (c) the porous beehive structure of the NiO/NiAl{sub 2}O{sub 4} particle is maintained, and the sintering behavior between different particles is not observed during cyclic studies. Those experimental results prove the sol-gel-derived oxygen carrier NiO/NiAl{sub 2}O{sub 4} is capable of being used in chemical-looping combustion fueled by coal char or H{sub 2}. 51 refs., 5 figs., 5 tabs.

Haibo Zhao; Liming Liu; Baowen Wang; Di Xu; Linlin Jiang; Chuguang Zheng [Huazhong University of Science and Technology, Wuhan (China). State Key Laboratory of Coal Combustion

2008-03-15T23:59:59.000Z

75

Effect of boundary scattering on the thermal conductivity of TiNiSn-based half-Heusler alloys  

Science Journals Connector (OSTI)

TiNiSn-based half-Heusler alloys have been of significant interest for their potential as thermoelectric materials. They exhibit promising electronic transport properties as revealed through high Seebeck coefficient and moderate electrical resistivity values. The chief disadvantage of these materials is a comparatively high lattice thermal conductivity. Attempts to “tune” the lattice thermal conductivity (?L) in these materials have led to the comparison and analysis of the thermal conductivity of two series of Ti- and Zr-based half-Heusler alloys. In the first series, Ti1?yZryNiSn0.95Sb0.05, a significant reduction in ?L is observed, with the substitution of large concentrations of Zr (y?25%) at Ti site, which is most likely due to mass fluctuation scattering. In the second series, TiNiSn1?xSbx, a nonsystematic increase in ?L is observed, with minute amounts of Sb doping (x?5%) at the Sn site. Extensive microstructural analysis in a TiNiSn1?xSbx series reveals a correlation between ?L and the average grain diameter in these materials, which is in good agreement with theoretical predictions related to phonon boundary scattering. In addition, a comparison of the calculated phonon mean free path in each of the series of compounds shows some insight into the two different phonon scattering mechanisms.

S. Bhattacharya; M. J. Skove; M. Russell; T. M. Tritt; Y. Xia; V. Ponnambalam; S. J. Poon; N. Thadhani

2008-05-30T23:59:59.000Z

76

Low thermal expansion behavior and thermal durability of ZrTiO4Al2TiO5Fe2O3 ceramics between 750 and 1400  

E-Print Network (OSTI)

2002 Abstract The thermal-shock-resistant materials in the system Al2TiO5­ZrTiO4 (ZAT) were synthesized Aluminum titanate (Al2TiO5) is well-known as an excellent thermal shock-resistant material, resulting from. All rights reserved. Keywords: Al2TiO5; Thermal expansion; Thermal shock resistance 1. Introduction

Cao, Guozhong

77

Influence of Si content on microstructure of TiAl alloys  

SciTech Connect

A systematic study of four ternary TiAl-based alloys with constant Ti content of 52.2 at. % and variable Si content ranging from 0.3 to 2.7 at. % (Al in balance) was conducted. The alloys were prepared from elemental powders via a route including powder mixing, precompaction, cold extrusion, and reactive hot-isostatic pressing. All investigated alloys contain the intermetallic compounds {gamma}-TiAl, {alpha}{sub 2}-Ti{sub 3}Al, and {zeta}-Ti{sub 5}(Si,Al){sub 3}. The microstructure can be described as a duplex structure (i.e., lamella {gamma}/{alpha}{sub 2} regions distributed in a {gamma} matrix) containing {zeta} precipitates. With increasing Si content, the number of primary {zeta} precipitates increased and the {gamma} grain size became finer while the lamellar volume fraction decreased slightly.

Hsu, F.Y.; Klaar, H.J. [Aachen Univ. of Technology (Germany). Central Lab. of Electron Microscopy] [Aachen Univ. of Technology (Germany). Central Lab. of Electron Microscopy; Wang, G.X. [Zhejiang Univ., Hangzhou (China)] [Zhejiang Univ., Hangzhou (China); Dahms, M. [GKSS Research Center, Geesthacht (Germany)] [GKSS Research Center, Geesthacht (Germany)

1996-04-01T23:59:59.000Z

78

Thermodynamic modeling and experimental validation of the Fe-Al-Ni-Cr-Mo alloy system  

SciTech Connect

NiAl-type precipitate-strengthened ferritic steels have been known as potential materials for the steam turbine applications. In this study, thermodynamic descriptions of the B2-NiAl type nano-scaled precipitates and body-centered-cubic (BCC) Fe matrix phase for four alloys based on the Fe-Al-Ni-Cr-Mo system were developed as a function of the alloy composition at the aging temperature. The calculated phase structure, composition, and volume fraction were validated by the experimental investigations using synchrotron X-ray diffraction and atom probe tomography. With the ability to accurately predict the key microstructural features related to the mechanical properties in a given alloy system, the established thermodynamic model in the current study may significantly accelerate the alloy design process of the NiAl-strengthened ferritic steels.

Teng, Zhenke [ORNL; Zhang, F [CompuTherm LLC, Madison, WI; Miller, Michael K [ORNL; Liu, Chain T [Hong Kong Polytechnic University; Huang, Shenyan [ORNL; Chou, Y.T. [Multi-Phase Services Inc., Knoxville; Tien, R [Multi-Phase Services Inc., Knoxville; Chang, Y A [ORNL; Liaw, Peter K [University of Tennessee, Knoxville (UTK)

2012-01-01T23:59:59.000Z

79

NiTi shape-memory transformations: minimum-energy pathways between austenite, martensites, and kinetically-limited intermediate states  

E-Print Network (OSTI)

NiTi is the most used shape-memory alloy, nonetheless, a lack of understanding remains regarding the associated structures and transitions, including their barriers. Using a generalized solid-state nudge elastic band (GSSNEB) method implemented via density-functional theory, we detail the structural transformations in NiTi relevant to shape memory: those between body-centered orthorhombic (BCO) groundstate and a newly identified stable austenite ("glassy" B2-like) structure, including energy barriers (hysteresis) and intermediate structures (observed as a kinetically limited R-phase), and between martensite variants (BCO orientations). All results are in good agreement with available experiment. We contrast the austenite results to those from the often-assumed, but unstable B2. These high- and low-temperature structures and structural transformations provide much needed atomic-scale detail for transitions responsible for NiTi shape-memory effects.

Zarkevich, N A

2014-01-01T23:59:59.000Z

80

Characterization of TiN, TiC and TiCN coatings on Ti50.6 at.% Ni alloy deposited by PIII and deposition technique  

E-Print Network (OSTI)

high content of nickel [1]. In addition, its wear resistance is expected to be improved by transition-metal as nitride, carbide and carbonitride, respectively. Based on the electrochemical measurement and ion carbides and nitrides coatings at a rather broad composition range, such as TiN, TiC and TiC1-xNx (0bÃ?b1

Zheng, Yufeng

Note: This page contains sample records for the topic "ni ti al" 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

Mechanism(s) of Ni Sorption on Al-Hydroxy-Interlayered Vermiculite Using Time-Resolved EXAFS  

E-Print Network (OSTI)

Mechanism(s) of Ni Sorption on Al-Hydroxy-Interlayered Vermiculite Using Time-Resolved EXAFS D. R role in retaining these compounds. However, little research has been done to investigate the sorption of Ni when reacted with Al-pillared vermiculite over various times. The sorption of Ni increased when

Sparks, Donald L.

82

Synthesis and structure of Al clusters supported on TiO2,,110...: A scanning tunneling microscopy study  

E-Print Network (OSTI)

Synthesis and structure of Al clusters supported on TiO2,,110...: A scanning tunneling microscopy, Texas 77843-3255 Received 14 October 1997; accepted 6 April 1998 Al clusters supported on TiO2(110) have been investigated using scanning tunneling microscopy. Al interacts strongly with the TiO2(110) surface

Goodman, Wayne

83

Spillover sites on a 19% Ni/Al sub 2 O sub 3 catalyst  

SciTech Connect

Two distinct methanation sites are clearly identified on a 19% Ni/Al{sub 2}O{sub 3} catalyst by temperature-programmed reaction (TPR) employing isotope labeling. The two sites, which are present after reduction at 975 K, are due to CO adsorption on Ni crystallites and CO and H spillover onto the Al{sub 2}O{sub 3} support. The concentration of sites on the support is 250 {mu}mol/G Al{sub 2}O{sub 3} (5 {times} 10{sup 13} molecules/cm{sup 2}), which is the same value measured for a 5.1% Ni/Al{sub 2}O{sub 3} catalyst and for a 1.0% Ru/Al{sub 2}O{sub 3} catalyst. Temperature-programmed desorption suggest that the CO and H on the Al{sub 2}O{sub 3} are in the form of a H-CO complex. The formation of this complex is an activated process, which is related to the activated adsorption of H{sub 2}. The H{sub 2} that adsorbs between 300 and 385 K is responsible for this spillover process onto the Al{sub 2}O{sub 3}. Isotope labeling and TPR were used to verify that a H-CO complex does not form on Ni/SiO{sub 2} catalysts. Carbon monoxide adsorption on Ni/SiO{sub 2} was not activated and only one methanation site was seen.

Sen, B.; Falconer, J.L. (Univ. of Colorado, Boulder (USA))

1989-06-01T23:59:59.000Z

84

Characterization of Ultrathin Films of -Al2O3 and the Chemistry of 1,3-Butadiene on NiAl(001) and -Al2O3  

E-Print Network (OSTI)

Characterization of Ultrathin Films of -Al2O3 and the Chemistry of 1,3-Butadiene on NiAl(001) and -Al2O3 Michelle M. Ivey, Kathryn A. Layman, Armen Avoyan, Heather C. Allen, and John C. HemmingerVine, California 92697 ReceiVed: October 3, 2002; In Final Form: March 27, 2003 Ultrathin films of -Al2O3 grown

85

On the Liquid/Solid Phase Equilibria in the Al-Rich Corner of the Al-Si-Ti Ternary System  

E-Print Network (OSTI)

On the Liquid/Solid Phase Equilibria in the Al-Rich Corner of the Al-Si-Ti Ternary System O; published online February 5, 2014) The nature of liquid-solid phase equilibria in the Al-rich corner of the Al-Si-Ti system are determined by drawing three isothermal sections at 620, 680 and 727 °C

Paris-Sud XI, Université de

86

Scaling relationship on macroscopic helical domains in NiTi tubes Y.J. He, Q.P. Sun *  

E-Print Network (OSTI)

that determines the size and shape of the helical domain and what is the effect of dry- friction type stress: Macroscopic helical domains Martensitic phase transformation NiTi shape memory alloy tube Energy minimization- ized in a helix-shaped macro-domain consisting of almost fully transformed grains whose statistical

Sun, Qing-Ping

87

Structural model for the Al72Ni20Co8 decagonal quasicrystals National Renewable Energy Laboratory, Golden, Colorado 80401  

E-Print Network (OSTI)

Structural model for the Al72Ni20Co8 decagonal quasicrystals Yanfa Yan National Renewable Energy, Oak Ridge, Tennessee 37831 Received 15 February 2000 We propose a structure model for the Al72Ni20Co8 decagonal quasicrystals based on its 2 -inflated Al13Co4 approximant phase: Applying a 105 screw operation

Pennycook, Steve

88

Vacancy ordered phases in AlCuNi as average lattices Anandh Subramaniam a,*, S. Ranganathan b  

E-Print Network (OSTI)

Vacancy ordered phases in Al­Cu­Ni as average lattices Anandh Subramaniam a,*, S. Ranganathan b, Bangalore 560012, India Abstract Vacancy ordered phases (VOP) in the Al­Cu­Ni system have an arrangement. Introduction Vacancy ordered phases (VOP) in Al-TM (transition metal) systems are a special class of structures

Subramaniam, Anandh

89

Flat panel display using Ti-Cr-Al-O thin film  

DOE Patents (OSTI)

Thin films of Ti--Cr--Al--O are used as a resistor material. The films are rf sputter deposited from ceramic targets using a reactive working gas mixture of Ar and O.sub.2. Resistivity values from 10.sup.4 to 10.sup.10 Ohm-cm have been measured for Ti--Cr--Al--O film <1 .mu.m thick. The film resistivity can be discretely selected through control of the target composition and the deposition parameters. The application of Ti--Cr--Al--O as a thin film resistor has been found to be thermodynamically stable, unlike other metal-oxide films. The Ti--Cr--Al--O film can be used as a vertical or lateral resistor, for example, as a layer beneath a field emission cathode in a flat panel display; or used to control surface emissivity, for example, as a coating on an insulating material such as vertical wall supports in flat panel displays.

Jankowski, Alan F. (Livermore, CA); Schmid, Anthony P. (Solan Beach, CA)

2002-01-01T23:59:59.000Z

90

Fabrication of TiO2 film with different morphologies on Ni anode and application in photoassisted water electrolysis  

Science Journals Connector (OSTI)

The anode of an alkaline electrolytic cell for water electrolysis was modified by TiO2 photocatalysts with different morphologies. The water electrolysis was coupled with photocatalytic decomposition of water by irradiation of UV light on the modified anode. And a feasible process for the hydrogen production of water electrolysis assisted by photocatalysis (WEAP) was proposed and experimentally confirmed. The results show that the highly ordered, vertically oriented tubular arrays structure on Ni anode surface has better hydrogen production performance than random TiO2. In WEAP process, the maximum rate of hydrogen production is 2.77 ml/(h*cm2) when the anode modified by ordered TiO2 nanotube arrays, compared to traditional alkaline electrolytic cell for water electrolysis with Ni anode, H2-production rate increased by 139%.

Hongbo He; Aiping Chen; Hui Lv; Haijun Dong; Ming Chang; Chunzhong Li

2013-01-01T23:59:59.000Z

91

Atomistic simulation of dislocation core structures in ordered TiAl  

SciTech Connect

Interatomic potentials of the Embedded Atom type were used in the simulation of the dislocation core structures in TiAl. Different orientations of the dislocation line were simulated for the most commonly observed TiAl slip systems. Low-temperature dislocation behavior is interpreted in terms of ordinary dislocation motion. The effect of applied stress on the shape of the dislocation core and its mobility is examined as well. For the superdislocations several possible types of dissociations were studied.

Panova, J.; Farkas, D. [Virginia Polytechnic Inst., Blacksburg, VA (United States). Dept. of Materials Science and Engineering

1995-12-31T23:59:59.000Z

92

Corrosion behavior of TiZrNiCuBe metallic glass coatings synthesized by electrospark deposition  

Science Journals Connector (OSTI)

Abstract Electrospark deposition was applied to successfully deposit TiZrNiCuBe metallic glass coating on 304L stainless steel. The coating was fully amorphous with the thickness of ?380 ?m. The corrosion behavior was investigated in 1, 6 and 11.5 mol/L HNO3. The optimal corrosion resistance was achieved in 6 mol/L HNO3 for the coating. The corrosion mechanism was discussed based on the effect of the structural heterogeneity on the corrosion resistance. It was found that the heterogeneous surface structure deteriorated the corrosion resistance. We believe that the coating will find a wide range of applications for protecting working parks in corrosive environments.

Congbo Li; Dehua Chen; Weiwei Chen; Lu Wang; Dawei Luo

2014-01-01T23:59:59.000Z

93

Preparation and properties of Al-PILC supported SO42?/TiO2 superacid catalyst  

Science Journals Connector (OSTI)

SO42?/TiO2/Al-pillared clay (ST/Al-PILC) superacid catalyst was prepared by loading active component SO42?/TiO2 on Al-pillared clay. The texture structure properties of the catalyst were studied by means of X-ray powder diffraction and the adsorption of N2. Acidity properties of the catalyst were tested by Hammett indicator method and FT-IR spectra of absorbed pyridine technique. The characterization results indicated that Al-PILC carrier could inhibit the formation of anatase TiO2 and the transformation of anatase TiO2 into rutile TiO2. ST/Al-PILC catalyst possesses both Lewis and Brönsted acid sites, and the number of acid sites on ST/Al-PILC is much larger than that on Al-PILC carrier, but its acid strength is lower than that of ST. Experimental results show that ST/Al-PILC is an effective catalyst for esterification of n-pentanol with benzoic acid.

Yue-Xiu Jiang; Xiao-Mei Chen; Yun-Fen Mo; Zhang-Fa Tong

2004-01-01T23:59:59.000Z

94

Short-range order of low-coverage Ti/Al,,111...: Implications for hydrogen storage in complex metal hydrides  

E-Print Network (OSTI)

Short-range order of low-coverage Ti/Al,,111...: Implications for hydrogen storage in complex metal-coverage Ti atoms on Al 111 as a model surface system for transition metal doped alanate hydrogen storage the dissociative chemisorption of hydrogen in Ti-doped alanate storage materials. © 2007 American Institute

Ciobanu, Cristian

95

The PUCOT for measuring dynamic Young's modulus for the B?-CoAl, FeAl and NiAl alloys  

E-Print Network (OSTI)

THE PUCOT FOR MEASURIN' DYNAMIC YOUNG'S MODULUS FOR THE B2-CoA1, FeA1 AND NiA1 ALLOYS A Thesis by MAHMOUD REDWAN HARMOUCHE Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree... function of Ni (in atomic %) is shown in Fig. 4. 4. Again, the data have been analyzed using LRA. An excellent fit to a straight line was found where the correlation between p and X3 is: pN Al = 2268. 64 + 71. 06 (X3) + 12. 02 kg/m 3 NiA1 with R...

Harmouche, Mahmoud Redwan

2012-06-07T23:59:59.000Z

96

Investigation of the {gamma}-Ti(Cr,Al)2 phase at 800 C and 1000 C  

SciTech Connect

A section of the Ti-Al-Cr ternary system, centered around the {gamma}-TiCr{sub 2} phase was examined using five quenched bulk alloy samples and three diffusion couples. Due to the sluggishness of diffusion both at 800 and 1,000 C in the TiCr{sub 2} phase fields, the heat treatment produced a state of near-equilibrium in the samples rather than complete equilibrium, as desired. However, as previous studies have made use of similar, or shorter, processing schedules, the results of the present study should be considered as valid as the earlier works. As a confirmation of the phase composition obtained from the near-equilibrium bulk alloys, the results of a diffusion couple analysis, yielded similar compositions. It is clear, based on the above results that the {gamma}-TiCr{sub 2}, with a C14 crystal structure, does indeed extend into the Ti-Al-Cr ternary system as indicated by Suprunenko et al. The {gamma}-TiCr{sub 2} phase advances into the ternary as the b solid solution pulls away from the Ti-Cr binary system with decreasing temperature. Solubility into the ternary system is made possible by Al atoms substituting onto Cr sites, as is observed for the Al-Cr-Nb ternary system. Although the solubility of the {gamma}-TiCr{sub 2} phase extends from about 3--19at% Al at 1,000 C and from 6--24at% Al at 800 C, the exact limits of solubility are yet to be determined.

Jewett, T.J.; Dahms, M. [GKSS Research Centre, Geesthacht (Germany)] [GKSS Research Centre, Geesthacht (Germany)

1995-05-15T23:59:59.000Z

97

Simply AlF3-treated Li4Ti5O12 composite anode materials for stable...  

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

Li4Ti5O12 composite anode materials for stable and ultrahigh power lithium-ion batteries. Simply AlF3-treated Li4Ti5O12 composite anode materials for stable and ultrahigh...

98

Microstructure and fracture toughness aspects of diffusion bonded interface between Ti and Al  

SciTech Connect

This study was undertaken to identify the microstructural characteristics of the intermetallic phases formed at the interface during the bonding process and determine the mechanical properties of Ti-Al dissimilar diffusion bonded joints, namely strength and fracture toughness. Furthermore, the effect of the intermetallic phases on the strength and fracture toughness of the joint was also determined. The effect of strength mis-match between Ti and Al on the fracture process will also be discussed. This investigation is the first phase of a larger project on the characterization of the intermetallics formed and their influence on strength and fracture toughness of the joints between TiAl-TiAl. A series of diffusion bonds of 25mm {times} 25 mm thick Ti bars were produced using aluminum foils of different thicknesses as interlayer. The bonded joints were tested to determine the fracture toughness properties of the interface formed and the effect of intermetallic phase formation on the fracture toughness was evaluated. Four-point bend specimens containing a crack introduced into the interface during the bonding process were tested to determine the diffusion-bonded interface fracture toughness. Tensile tests of the joints were also conducted to determine their strengths. The bonding conditions required to obtain a sound joint between Ti and Al were also evaluated.

Cam, G.; Dobi, D.; Kocak, M. [GKSS Research Center, Geesthacht (Germany); Heikinheimo, L.; Siren, M. [VTT Manufacturing Technology, Espoo (Finland)

1996-12-31T23:59:59.000Z

99

Al–Ge–Ti: Phase equilibria and structural characterization of new ternary compounds  

Science Journals Connector (OSTI)

Abstract Phase equilibria of Al–Ge–Ti have been investigated using scanning electron microscopy (SEM), powder X-ray diffraction (XRD) and differential thermal analysis (DTA). Partial isothermal sections at 400 °C, 520 °C and 1000 °C were obtained with focus on the titanium-poor part up to 50 at.% titanium. Three ternary compounds were found to exist. The compound Al3GeTi (?1) crystallizes in an own structure type (P4/nmm, tP10). Two structurally closely related compounds were found at the composition Al1?xGe1+xTi: ?2 (0.61 ? x ? 0.73), Al4Si5Zr3-type, I41/amd, tI24 and ? 2 ? (0.36 ? x ? 0.57), Si2Zr-type, Cmcm, oC12. DTA data were used to construct a ternary reaction scheme (Scheil diagram) up to approximately 1300 °C, a partial liquidus projection and two vertical sections, at 10 at.% Ti and at a constant Al:Ti ratio of 1:1. A total number of 12 ternary invariant reactions were identified.

Roland W. Bittner; Matthias Gürth; Liliana I. Duarte; Christian Leinenbach; Herta S. Effenberger; Klaus W. Richter

2014-01-01T23:59:59.000Z

100

Development of a nanostructure microstructure in the Al–Ni system using the electrospark deposition process  

Science Journals Connector (OSTI)

Electrospark deposition (ESD) was applied to produce aluminum–nickel coatings consisting of nanostructured Al and Al3Ni phases. An ESD electrode was manufactured from a hypo-eutectic aluminum–Al3Ni alloy using chill casting. Line deposition tests were performed to determine the optimal processing parameters resulting in a high quality deposit. X-ray diffraction (XRD) as well as optical and field emission scanning electron microscopy (FE-SEM), were performed to determine the composition and microstructure of the resulting depositions. It was determined that a capacitance of 20 ?F and a voltage of 100 V resulted in the highest quality deposition. Furthermore it was determined that the ESD process was capable of producing a microstructure consisting of highly refined aluminum and Al3Ni phases. The grain size of the aluminum phase was calculated, through the application of the Scherrer equation, to be ?25 nm. While, via scanning electron microscopy the grain size of the Al3Ni phase was determined to be ?44 nm. Also it was determined that multiple deposition passes resulted in increasing the thickness of the deposit, however resulted in decreased deposit quality. Furthermore, it was determined that increasing the energy-density (pulse-energy divided by electrode cross-sectional area) resulted in increasing deposit thickness, until a maximum was obtained using an energy-density of ?0.8 J/mm2. However, increasing the energy-density beyond this point resulted in decreased deposit quality.

D.W. Heard; M. Brochu

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ni ti al" 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

Electrical properties of the amorphous interfacial layer between Al electrodes and epitaxial NiO films  

SciTech Connect

The amorphous interfacial layer (a-IL) between Al electrode and epitaxial NiO films were studied using electron energy-loss spectroscopy (EELS) and energy-dispersive x-ray spectroscopy. Two distinct properties were found in the a-IL, i.e., a lower metallic and an upper insulating layer. EELS results revealed that the metallic Ni atoms were responsible for the conducting nature of the lower oxide amorphous layer. The resistance behavior of Al/a-IL/epi-NiO was changed from a high to a low resistance state after forming process. The resistance change could be explained by the formation of a nanocrystalline metal alloy in the insulating amorphous layer.

Hyuck Jang, Jae; Kwon, Ji-Hwan; Kim, Miyoung [Research Institute of Advanced Materials, Department of Materials Science and Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Ran Lee, Seung; Char, Kookrin [Department of Physics and Astronomy and Center for Strongly Correlated Materials Research, Seoul National University, Seoul 151-747 (Korea, Republic of)

2012-04-23T23:59:59.000Z

102

Spin conversion of positronium in NiO/Al2O3 catalysts observed by coincidence Doppler broadening technique  

Science Journals Connector (OSTI)

High-purity NiO/Al2O3 catalysts were prepared by mixing NiO and ?-Al2O3 nanopowders. X-ray diffraction patterns were measured to characterize the grain size and crystalline phase of the nanopowders. Positron-annihilation spectroscopy was used to study the microstructure and surface properties of the pores inside the NiO/Al2O3 catalysts. The positron lifetime spectrum comprises two short and two long lifetime components. The two long lifetimes ?3 and ?4 correspond to ortho-positronium (o-Ps) annihilated in microvoids and large pores, respectively. With increasing NiO content in the NiO/Al2O3 catalysts, both ?4 and its intensity I4 show continuous decrease. Meanwhile, the para-positronium (p-Ps) intensity, obtained from coincidence Doppler broadening spectra, increases gradually with NiO content. The different variation in o-Ps and p-Ps intensity suggests the ortho-para conversion of positronium in NiO/Al2O3 catalysts. X-ray photoelectron spectroscopy shows that Ni mainly exists in the form of NiO. The electron-spin-resonance measurements reveal that the ortho-para conversion of Ps is induced by the unpaired electrons of the paramagnetic centers of NiO.

H. J. Zhang; Z. Q. Chen; S. J. Wang; A. Kawasuso; N. Morishita

2010-07-28T23:59:59.000Z

103

Growth behavior and field-induced diffusion of Ni clusters/particles on SrTiO3 (001) observed by UHV-TEM/STM  

Science Journals Connector (OSTI)

The fundamental and technological importance of metal clusters and particles on oxide surfaces is growing. Here, room temperature deposited Ni clusters and particles on clean SrTiO3 (001) surfaces were analyzed w...

Miyoko Tanaka

2013-09-01T23:59:59.000Z

104

Effect of Ni/Al atomic ratio of mesoporous Ni–Al2O3 aerogel catalysts on their catalytic activity for hydrogen production by steam reforming of liquefied natural gas (LNG)  

Science Journals Connector (OSTI)

Mesoporous Ni–Al2O3 (XNiAE) aerogel catalysts with different Ni/Al atomic ratio (X) were prepared by a single-step sol-gel method and a subsequent CO2 supercritical drying method. The effect of Ni/Al atomic ratio of mesoporous \\{XNiAE\\} aerogel catalysts on their physicochemical properties and catalytic activity for steam reforming of liquefied natural gas (LNG) was investigated. Textural properties and chemical properties of \\{XNiAE\\} catalysts were strongly influenced by Ni/Al atomic ratio. Nickel species were highly dispersed on the surface of \\{XNiAE\\} catalysts through the formation of surface nickel aluminate phase. In the steam reforming of LNG, both LNG conversion and hydrogen yield showed volcano-shaped curves with respect to Ni/Al atomic ratio. Average nickel diameter of \\{XNiAl\\} catalysts was well correlated with LNG conversion and hydrogen yield over the catalysts. Among the catalysts tested, 0.35NiAE (Ni/Al = 0.35) catalyst with the smallest average nickel diameter showed the best catalytic performance. The highest surface area, the largest pore volume, the largest average pore size, and the highest reducibility of 0.35NiAE catalyst were also partly responsible for its superior catalytic performance.

Jeong Gil Seo; Min Hye Youn; Yongju Bang; In Kyu Song

2010-01-01T23:59:59.000Z

105

Recent advances in alloy design of Ni{sub 3}Al alloys for structural use  

SciTech Connect

This is a comprehensive review of recent advances in R&D of Ni{sub 3}Al-based alloys for structural use at elevated temperatures in hostile environments. Recent studies indicate that polycrystalline Ni{sub 3}Al is intrinsically quite ductile at ambient temperatures, and its poor tensile ductility and brittle grain-boundary fracture are caused mainly by moisture-induced hydrogen embrittlement when the aluminide is tested in moisture- or hydrogen-containing environments. Tensile ductility is improved by alloying with substitutional and interstitial elements. Among these additives, B is most effective in suppressing environmental embrittlement and enhancing grain-boundary cohesion, resulting in a dramatic increase of tensile ductility at room temperature. Both B-doped and B-free Ni{sub 3}Al alloys exhibit brittle intergranular fracture and low ductility at intermediate temperatures (300-850 C) because of oxygen-induced embrittlement in oxidizing environments. Cr is found to be most effective in alleviating elevated-temperature embrittlement. Parallel efforts on alloy development using physical metallurgy principles have led to development of several Ni{sub 3}Al alloys for industrial use. The unique properties of these alloys are briefly discussed. 56 refs, 15 figs, 3 tabs.

Liu, C.T.; George, E.P.

1996-12-31T23:59:59.000Z

106

Ni.sub.3 Al-based intermetallic alloys having improved strength above 850.degree. C.  

DOE Patents (OSTI)

Intermetallic alloys composed essentially of: 15.5% to 17.0% Al, 3.5% to 5.5% Mo, 4% to 8% Cr, 0.04% to 0.2% Zr, 0.04% to 1.5% B, balance Ni, are characterized by melting points above 1200.degree. C. and superior strengths at temperatures above 1000.degree. C.

Liu, Chain T. (Oak Ridge, TN)

2000-01-01T23:59:59.000Z

107

Ni3Al-based alloys for die and tool application  

DOE Patents (OSTI)

A novel Ni.sub.3 Al-based alloy exhibits strengths and hardness in excess of the standard base alloy IC-221M at temperatures of up to about 1000.degree. C. The alloy is useful in tool and die applications requiring such temperatures, and for structural elements in engineering systems exposed to such temperatures.

Liu, Chain T. (Oak Ridge, TN); Bloom, Everett E. (Kingston, TN)

2001-01-01T23:59:59.000Z

108

Kinetics of alloy formation at the interfaces in a Ni-Ti multilayer: X-ray and neutron reflectometry study  

Science Journals Connector (OSTI)

Vacuum-deposited Ni/Ti multilayers on annealing at different temperatures exhibit formation of ordered alloy layers at interfaces. We have studied in detail the formation of alloy at interfaces of a Ni/Ti multilayer on annealing at 300?°C and 400?°C using powder x-ray diffraction, x-ray reflectometry, polarized neutron reflectometry, and off-specular x-ray reflectometry techniques. Correlation among structural, magnetic, and morphological properties in as-deposited Ni/Ti multilayer as well as in a sample annealed at 300?°C and 400?°C has been studied. X-ray diffraction technique was used to obtain crystal structure of the sample. Specular x-ray reflectometry and neutron reflectometry were used to determine the growth of alloy layers from density profile, as a function of depth in the sample. From off-specular x-ray reflectivity we found that the in-plane correlation lengths at the interfaces grew with annealing. This is associated with alloy crystallite growth obtained from x-ray reflectometry. Detailed magnetic-moment density profile of as-deposited as well as annealed multilayer sample has been determined by polarized neutron reflectometry measurements, which was used to determine the magnetic nature of the alloy layers. The results show formation of nonmagnetic alloy layers at the interfaces on annealing. From the Bragg-peak intensities of x-ray reflectivity and polarized neutron reflectivity measurements, we have estimated the diffusion lengths after annealing at 300?°C and 400?°C.

Surendra Singh; Saibal Basu; Pramod Bhatt; A. K. Poswal

2009-05-28T23:59:59.000Z

109

Effect of Reactive Sputtering Parameters on TiAlN Nanocoating Structure and Morphology  

SciTech Connect

The effect of substrate bias and nitrogen flow rate on the TiAlN nanocoating structure and morphology has been investigated by using reactive unbalance DC magnetron sputtering. TiAlN nanocoating was deposited on the tungsten carbide insert tool and the structure and morphology were characterized by using XRD and AFM, respectively. The substrate bias was varied between 0 to -221 V and the nitrogen flow rate was varied between 30 to 72 sccm. The results showed that the structure of TiAlN nanocoating consisted of mainly (111) and (200) plane. The structure was significatly influenced by substrate bias in promoting finer crystal size and increased crystal plane spacing while the rms roughness of nanocoating was influenced by substrate bias and nitrogen flow rate.

Budi, Esmar [Jurusan Fisika FMIPA Universitas Negeri Jakarta Jl. Pemuda No. 10 Rawamangun Jakarta 13220 (Indonesia); Razali, M. Mohd.; Nizam, A. R. Md. [Faculty of Manufacturing Engineering Universiti Teknikal Malaysia Melaka (UTeM) Karung Berkunci No 1752 Pejabat Pos Durian Tunggal 76109 Melaka (Malaysia)

2010-10-24T23:59:59.000Z

110

Preparation of Al2O3/TiO2-containing Coating on Aluminium Alloys by Micro-arc Oxidation  

Science Journals Connector (OSTI)

TiO2-containing ceramic coatings were deposited on the surface of aluminium alloys by micro-arc oxidition. Surface and cross-section topograph of ceramic coating were observed using scanning electron microscopy (SEM). The phase composition of ceramic ... Keywords: Micro-arc oxidation, TiO2 additive, Al2O3/TiO2 phase, antiwear behavior

Cheng Gao; Jinyong Xu; Yusheng Lan; Yonghui Ma; Weixiang Su; Yajuan Liu

2010-03-01T23:59:59.000Z

111

Lattice variations of Ti-6Al-4V alloy with hydrogen content  

SciTech Connect

Effect of hydrogen content on the lattice parameter of Ti-6Al-4V alloy has been investigated by X-ray diffraction. The experimental results show that the solution of hydrogen in the Ti-6Al-4V alloy affects significantly on the lattice parameters of {alpha}, {beta} and {delta} phases, especially the {beta} phase. Furthermore, the critical hydrogen content of {delta} hydride formation for Ti-6Al-4V alloy is 0.385 wt.%. When the hydrogen content is lower than the critical hydrogen content, the {delta} hydride cannot precipitate and the lattice parameter ({alpha}) of {beta} phase linearly increases with the increasing of hydrogen content. When the hydrogen content is higher than the critical hydrogen content, the {delta} hydride precipitates and the lattice parameter ({alpha}) of {beta} phase varies inconspicuously with hydrogen content. In addition, the effects of lattice variations and {delta} hydride formation on microstructure are discussed. The {alpha}/{beta} interfaces of lamellar transformed {beta} phase become fuzzy with the increasing of hydrogen content because of the lattice expansion of {beta} phase. Compared with that of the Ti-6Al-4V alloy at low hydrogen content ({<=} 0.385 wt.%), the contrasts of primary {alpha} phase and transformed {beta} phase of Ti-6Al-4V alloy at high hydrogen content ({>=} 0.385 wt.%) were completely reversed due to the formation of {delta} hydride. - Research Highlights: {yields} A novel method for determining {delta} hydride in Ti-6Al-4V alloy is presented. {yields} The critical hydrogen content of {delta} hydride formation is 0.385 wt.%. {yields} The lattice parameter of {beta} phase can be expressed as follows: a=0.323(1+9.9x10{sup -2}C{sub H}) . {yields} Precipitation of {delta} hydride has a significant influence on the microstructure. {yields} The {alpha}/{beta} interfaces of transformed {beta} phase became fuzzy in the hydrogenated alloy.

Zhu Tangkui, E-mail: zhutangkui@sohu.com; Li, Miaoquan, E-mail: honeymli@nwpu.edu.cn

2011-07-15T23:59:59.000Z

112

Photodissociation measurements of bond dissociation energies: D0(Al2-Al), D0(TiO -Mn), and D0(V2 -V)  

E-Print Network (OSTI)

Photodissociation measurements of bond dissociation energies: D0(Al2-Al), D0(TiO -Mn), and D0(V2 -VV was obtained by adding the energy of the 4 A2 state to the measured predissociation threshold. For Ti studies may be used to measure bond lengths and deduce term symbols. As one proceeds to higher energies

Morse, Michael D.

113

Microstructure and tensile properties of spray formed gamma Ti48.9at.%Al  

SciTech Connect

Until now only a limited number of spray forming experiments on TiAl were reported, and the mechanical data of sprayed material of these alloys are rather rare. In this paper, the application of the EIGA-technique (Electrode Induction Melting Gas Atomization) for spray forming of binary Ti48.9Al(at.%) is reported. Sprayed deposits, obtained under near optimum conditions are tensile tested at room temperature and microstructurally characterized. The results are compared to similar alloys obtained by other process routes.

Liu, K.W. [GKSS Forschungszentrum, Geesthacht (Germany)] [GKSS Forschungszentrum, Geesthacht (Germany); [Univ. of Science and Technology, Beijing (China). State Kay Lab for Advanced Metals and Materials; Gerling, R.; Schimansky, F.P. [GKSS Forschungszentrum, Geesthacht (Germany)] [GKSS Forschungszentrum, Geesthacht (Germany)

1999-02-05T23:59:59.000Z

114

Study of 3D Laser Cladding for Ni85Al15 Superalloy  

Science Journals Connector (OSTI)

Abstract Conditions of successful3D laser cladding for Ni based superalloy were studied. A high power Yb-YAG laser was used to create a molten pool on a stainless steel substrate into which Ni85Al15 powder stream was delivered to create 3D samples. The effect of different laser parameters on the structure and the intermetallic phase content of the manufactured samples were explored by optical metallography, microhardness, SEM, X-ray, and EDX analysis. The cladding of the Ni3A1 coating with small dilution into substrate can be obtained at the appropriate power density of about 2-8 J/mm2 under the laser scan velocity of 100-200 mm/min and the powder feed rate ? 3.8 g/min.

D. Kotoban; S. Grigoriev; I. Shishkovsky

2014-01-01T23:59:59.000Z

115

State of Ni in catalysts for glycerol hydrogenation and methane steam reforming as studied by X-ray absorption spectroscopy  

Science Journals Connector (OSTI)

X-ray absorption spectroscopy is used to study 1% Ni/Al2O3, 5% Ni/Al2O3, and 5% Ni/TiO2 catalysts for glycerol and methane conversion. The effect of treatment in H2 under microwave irradiation on the reduction of...

O. P. Tkachenko; L. M. Kustov

2013-06-01T23:59:59.000Z

116

Catalytic Effect of Ti for Hydrogen Cycling in NaAlH4  

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

Effect of Ti for Effect of Ti for Hydrogen Cycling in NaAlH 4 Mei-Yin Chou School of Physics Georgia Institute of Technology (DE-FG02-05ER46229) Acknowledgment: Yan Wang, Roland Stumpf Why is NaAlH 4 interesting? A viable candidate for hydrogen-storage material: High theoretical weight-percent hydrogen content of 5.55% and low cost But (before 1997) Dehydrogenation occurs at high temperature; rehydrogenation is difficult. Bogdanovic and Schwickardi, 1997 Hydrogen can be reversibly absorbed and desorbed from NaAlH 4 under moderate conditions by the addition of catalysts (compounds containing Ti, Zr, etc.) High Hydrogen Contents in Complex Hydrides Hydride wt% Hydride wt% Be(BH 4 ) 2 20.8 Mg(AlH 4 ) 2 9.3 LiBH 4 18.2 Ca(AlH 4 ) 2 7.9 Mg(BH 4 ) 2 14.9 KBH 4 7.5 Ca(BH 4 ) 2 11.6 NaAlH 4 7.5 NaBH4 10.7 Ga(AlH

117

Improving the phase stability and oxidation resistance of B-NiAl  

SciTech Connect

High temperature alloys are essential to many industries that require a stable material to perform in harsh oxidative environments. Many of these alloys are suited for specific applications such as jet engine turbine blades where most other materials would either melt or oxidize and crumble (1). These alloys must have a high melting temperature, excellent oxidation resistance, good creep resistance, and decent fracture toughness to be successfully used in such environments. The discovery of Ni based superalloys in the 1940s revolutionized the high temperature alloy industry and there has been continued development of these alloys since their advent (2). These materials are capable of operating in oxidative environments in the presence of combustion gases, water vapor and at temperatures around 1050 C. Demands for increased f uel efficiency, however, has highlighted the need for materials that can be used under similar atmospheres and at temperatures in excess of 1200 C. The current Ni based superalloys are restricted to lower temperatures due to the presence of a number of low melting phases that result in softening of the alloys above 1000 C. Therefore, recent research has been aimed at exploring and developing newer alloy systems that can meet the escalating requirements. This thesis comprises a part of such an effort. The motivation of this work is to develop a novel high temperature alloy system that shows improved performance at higher temperatures than the currently employed alloys. The desired alloy should be in accordance with the requirements established in the National Energy Technology Laboratory (NETL) FutureGen program having an operating temperature around 1300 C. Alloys based on NiAl offer significant potential payoffs as structural materials in gas turbine applications due to a unique range of physical and mechanical properties. Alloying additions to NiAl could be used to further improve the pertinent properties that currently limit this system from replacing Ni based superalloys. Modifications to NiAl were explored to increase the phase stability and oxidation resistance which would allow these alloys to be used at even higher temperatures yielding greater efficiencies. The extended Miedema model was an effective tool that screened all of the potential phase space for ternary substitutions to NiAl and found the few potential systems worth further investigation. After production of the alloys it was determined that Ir, Rh, and Pd were the top candidates for substitution on Ni site up to 12 at%. The melting temperature of NiAl could be increased as much as 150 C with 12 at% Ir and 130 C with 12 at% Rh substitution. Pall adium on the other hand decreased the melting temperature by 50 C at the 12 at% substitution level. The grain size was found to have a profound influence on the oxidation resistance. Both Ir and Rh substitutions resulted in finer grain sizes compared to Pd substitutions or base NiAl. The grain size increased drastically during high temperature annealing with the PGM substitutions hindering grain growth only slightly. However, the addition of 0.05 at% Hf limited the grain growth dramatically during high temperature annealing. NiAl inherently has respectable oxidation resistance up to 1100 C. It was found through experimental testing that both Ir and Rh substitutions improve the oxidation resistance of NiAl at ultra-high temperatures with Ir performing the best. Both PGM substitutions decreased the growth rate as well as forming a more adherent oxide scale. Pd substitutions appeared to have a negligible effect to the oxidation resistance of NiAl. Hafnium addition of 0.05 at% was found to decrease the oxidation rate as well as increase the scale adherence. The combination of both Ir substitution (6-9 at%) and Hf addition (0.05 at%) produced the alloy with the best oxidation resistance. Although improvements in phase stability and oxidation resistance have been made to the NiAl system, more development and testing are still needed. Two major issues yet to be resolved are the low fracture toughn

Brammer, Travis

2011-08-15T23:59:59.000Z

118

Application of FIB microsampling technique to long-period ordered TiAl single crystal with composition gradient  

Science Journals Connector (OSTI)

......and 3 Department of Materials Science and Engineering...for Electronics and Materials, Kyushu University...Transmission Specimen Handling Titanium chemistry...for Electronics and Materials and 2 Art, Science...In a Ti-Al phase diagram, a g-TiAl intermetallic......

Satoshi Hata; Kohjiro Shiraishi; Masaru Itakura; Noriyuki Kuwano; Takayoshi Nakano; Yukichi Umakoshi

2004-10-01T23:59:59.000Z

119

Characterization of Ni/Al multilayer on Si substrate by diffraction and reflectometry techniques  

SciTech Connect

An ion beam deposited multilayer film of nominal thickness [Ni(200 Angst )/Al(100 Angst )]x5 on Si substrate has been characterized by X-Ray Diffraction(XRD), X-Ray Reflectivity (XRR) and Polarized neutron reflectivity(PNR). The present paper attempts to identify presence of any intermetallic compounds at the interfaces of the as-deposited sample. Structural parameters obtained from XRR and PNR are close to design values.

Swain, Mitali; Basu, Saibal; Bhattacharya, Debarati; Gupta, Mukul [Solid State Physics Division Bhabha Atomic Research Center, Mumbai 400085 (India); UGC-DAE-Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452017 (India)

2012-06-05T23:59:59.000Z

120

High Temperature Oxidation Behavior of gamma-Ni+gamma'-Ni3Al Alloys and Coatings Modified with Pt and Reactive Elements  

SciTech Connect

Materials for high-pressure turbine blades must be able to operate in the high-temperature gases (above 1000 C) emerging from the combustion chamber. Accordingly, the development of nickel-based superalloys has been constantly motivated by the need to have improved engine efficiency, reliability and service lifetime under the harsh conditions imposed by the turbine environment. However, the melting point of nickel (1455 C) provides a natural ceiling for the temperature capability of nickel-based superalloys. Thus, surface-engineered turbine components with modified diffusion coatings and overlay coatings are used. Theses coatings are capable of forming a compact and adherent oxide scale, which greatly impedes the further transport of reactants between the high-temperature gases and the underlying metal and thus reducing attack by the atmosphere. Typically, these coatings contain {beta}-NiAl as a principal constituent phase in order to have sufficient aluminum content to form an Al{sub 2}O{sub 3} scale at elevated temperatures. The drawbacks to the currently-used {beta}-based coatings, such as phase instabilities, associated stresses induced by such phase instabilities, and extensive coating/substrate interdiffusion, are major motivations in this study to seek next-generation coatings. The high-temperature oxidation resistance of novel Pt + Hf-modified {gamma}-Ni + {gamma}-Ni{sub 3}Al-based alloys and coatings were investigated in this study. Both early-stage and 4-days isothermal oxidation behavior of single-phase {gamma}-Ni and {gamma}{prime}-Ni{sub 3}Al alloys were assessed by examining the weight changes, oxide-scale structures, and elemental concentration profiles through the scales and subsurface alloy regions. It was found that Pt promotes Al{sub 2}O{sub 3} formation by suppressing the NiO growth on both {gamma}-Ni and {gamma}{prime}Ni{sub 3}Al single-phase alloys. This effect increases with increasing Pt content. Moreover, Pt exhibits this effect even at lower temperatures ({approx}970 C) in the very early stage of oxidation. It was also inferred that Pt enhances the diffusive flux of aluminum from the substrate to the scale/alloy interface. Relatively low levels of hafnium addition to Pt-free {gamma}{prime}-Ni{sub 3}Al increased the extent of external NiO formation due to non-protective HfO{sub 2} formation. Accordingly, this effect intensified with increasing Hf content from 0.2 to 0.5 at.%.

Nan Mu

2007-12-01T23:59:59.000Z

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121

Molecular dynamics simulations of the melting curve of NiAl alloy under pressure  

SciTech Connect

The melting curve of B2-NiAl alloy under pressure has been investigated using molecular dynamics technique and the embedded atom method (EAM) potential. The melting temperatures were determined with two approaches, the one-phase and the two-phase methods. The first one simulates a homogeneous melting, while the second one involves a heterogeneous melting of materials. Both approaches reduce the superheating effectively and their results are close to each other at the applied pressures. By fitting the well-known Simon equation to our melting data, we yielded the melting curves for NiAl: 1783(1 + P/9.801){sup 0.298} (one-phase approach), 1850(1 + P/12.806){sup 0.357} (two-phase approach). The good agreement of the resulting equation of states and the zero-pressure melting point (calc., 1850 ± 25 K, exp., 1911 K) with experiment proved the correctness of these results. These melting data complemented the absence of experimental high-pressure melting of NiAl. To check the transferability of this EAM potential, we have also predicted the melting curves of pure nickel and pure aluminum. Results show the calculated melting point of Nickel agrees well with experiment at zero pressure, while the melting point of aluminum is slightly higher than experiment.

Zhang, Wenjin; Peng, Yufeng [College of Physics and electronic Engineering, Henan Normal University, Xinxiang, 453007 (China)] [College of Physics and electronic Engineering, Henan Normal University, Xinxiang, 453007 (China); Liu, Zhongli, E-mail: zhongliliu@yeah.net [College of Physics and Electric Information, Luoyang Normal University, Luoyang, 471002 (China)] [College of Physics and Electric Information, Luoyang Normal University, Luoyang, 471002 (China)

2014-05-15T23:59:59.000Z

122

Surface Engineering to Improve the Durability and Lubricity of Ti-6Al-4V Alloy  

SciTech Connect

Titanium alloys offer high strength, high corrosion resistance, and the opportunity to reduce the weight of heavy vehicle engine components, but they do not perform well as bearing surfaces without further treatments or coatings. This paper explores a series of surface engineering treatments to improve the friction and wear behavior of Ti-6Al-4V alloy under diesel engine oil-lubricated conditions.

Bansal, Dinesh G [ORNL; Eryilmaz, Osman L [Argonne National Laboratory (ANL); Blau, Peter Julian [ORNL

2011-01-01T23:59:59.000Z

123

Microscopic mechanisms of metastable phase formation during ball milling of intermetallic TiAl phases  

SciTech Connect

Powders of the intermetallic equilibrium phases {alpha}{sub 2}-Ti{sub 3}Al, {gamma}-TiAl and TiAl{sub 3} were ball milled in order to investigate the microscopic origins of the energetic destabilization and the transformation into metastable phases during the milling process. It was found that the intermetallic phases were chemically partially disordered on milling followed by the transformation into solid solution phases after long milling. In detail, for the {gamma} phase, the formation of numerous deformation twins, thin h.c.p. lamellae and lamellae of the 9R phase formed by an antitwin operation was observed by TEM. The disordering of the D0{sub 22}-TiAl{sub 3} phase occurred inhomogeneously in the material via the formation of antiphase boundaries on (001) planes, resulting in a f.c.c. solid solution in the final state. In summary, it can be concluded that the formation of the observed metastable phases results from chemical disordering, whereas the excess enthalpy of grain boundaries plays only a minor role for the energetical destabilization of the intermetallic compounds during milling in this case.

Klassen, T.; Oehring, M.; Bormann, R. [GKSS Research Centre, Geesthacht (Germany)] [GKSS Research Centre, Geesthacht (Germany)

1997-09-01T23:59:59.000Z

124

Crack initiation and crack growth resistance of Ti-48Al-2Cr sheet material  

SciTech Connect

The present paper reports on the fracture toughness tests conducted on Ti-48Al-2Cr sheet material with near-gamma microstructure produced by hot rolling. Compact tension specimens were sectioned from sheet material and tested at room temperature to determine the fracture toughness and crack growth resistance curves. The deformation and fracture behavior were studied on tested specimens.

Dogan, B.; Schwalbe, K.H. [GKSS Research Centre, Geesthacht (Germany)] [GKSS Research Centre, Geesthacht (Germany); Clemens, H. [Plansee AG, Reutte (Austria)] [Plansee AG, Reutte (Austria)

1998-03-03T23:59:59.000Z

125

Direct Laser Deposition of a Single-Crystal Ni3Al-Based IC221W Alloy  

E-Print Network (OSTI)

process based on laser cladding, which involves laser processing fine metallic powders into fully denseDirect Laser Deposition of a Single-Crystal Ni3Al-Based IC221W Alloy WEIPING LIU and J.N. Du221W alloy were produced on a SX Ni-base superalloy substrate by means of the laser-engineered net

DuPont, John N.

126

Use of periodic approximants in a dynamical LEED study of the quasicrystalline tenfold surface of decagonal Al-Ni-Co  

E-Print Network (OSTI)

of decagonal Al-Ni-Co K. Pussi Department of Electrical Engineering, Lappeenranta University of Technology, P.O. Box 20, FIN-53851 Lappeenranta, Finland N. Ferralis Physics Department and Materials Research

Widom, Michael

127

Stress Development and Relaxation in Al2O3 during Early StageOxidation of beta-NiAl  

SciTech Connect

Using a glancing synchrotron X-ray beam (Advanced Photon Source, Beamline 12BM, Argonne National Laboratory), Debye-Scherrer diffraction patterns from thermally grown oxides on NiAl samples were recorded during oxidation at 1000 or 1100 C in air. The diffraction patterns were analyzed to determine strain and phase changes in the oxide scale as it developed and evolved. Strain was obtained from measurements of the elliptical distortion of the Debye-Scherrer rings, where data from several rings of a single phase were used. Results were obtained from {alpha}-Al{sub 2}O{sub 3} as well as from the transition alumina, in this case {theta}-Al{sub 2}O{sub 3}, which formed during the early stage. Compressive stress was found in the first-formed transition alumina, but the initial stress in {alpha}-Al{sub 2}O{sub 3} was tensile, with a magnitude high enough to cause Al{sub 2}O{sub 3} fracture. New {alpha}-Al{sub 2}O{sub 3} patches nucleated at the scale/alloy interface and spread laterally and upward. This transformation not only puts the alpha alumina in tension, but can also cause the transition alumina to be in tension. After a complete {alpha}-Al{sub 2}O{sub 3} layer formed at the interface, the strain level in {alpha}-Al{sub 2}O{sub 3} became compressive, reaching a steady state level around -75 MPa at 1100 C. To study a specimen's response to stress perturbation, samples with different thickness, after several hours of oxidation at 1100 C, were quickly cooled to 950 C to impose a compressive thermal stress in the scale. The rate of stress relaxation was the same for 1 and 3.5 mm thick samples, having a strain rate of {approx} 1 x 10{sup -8}/s. This behavior indicates that oxide creep is the major stress relaxation mechanism.

Hou, P.Y.; Paulikas, A.P.; Veal, B.W.

2005-04-20T23:59:59.000Z

128

Ba Deposition and Oxidation on ?-Al2O3/NiAl(100) Ultrathin Films. Part I: Anaerobic Deposition Conditions  

SciTech Connect

Room temperature Ba deposition on an oxygen terminated ?-Al2O3/NiAl(100) ultrathin film substrate under ultra high vacuum (UHV) conditions is studied using X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and temperature programmed desorption (TPD) techniques. In addition, Ba oxidation by the alumina substrate at 300 K < T < 1200 K in the absence of a gas phase oxidizing agent is investigated. Our results indicate that at room temperature Ba grows in a layer by layer fashion for the first two layers and Ba is partially oxidized. Annealing at T < 700 K results in further oxidation of the Ba species whereas annealing at higher temperatures leads to loss of Ba from the surface via desorption.

Ozensoy, Emrah; Peden, Charles HF; Szanyi, Janos

2006-05-19T23:59:59.000Z

129

Influence of dislocation-solute interactions on the mechanical properties of zirconium-doped NiAl  

SciTech Connect

Atom probe field ion microscopy (APFIM) has been used to characterize NiAl microalloyed with molybdenum and zirconium. Field ion images and atom probe analyses revealed segregation of zirconium to dislocation strain fields and ribbon-like morphological features that are probably related to dislocations. These results provide direct experimental evidence in support of the suggestion that the tremendous increase in the ductile-to-brittle transition temperature (DBTI) in zirconium-doped NiAl is due to pinning of dislocations by zirconium atoms. Atom probe analyses also revealed segregation of zirconium to grain boundaries. This result is consistent with the change from an intergranular fracture mode in undoped NiAl to a mixture of intergranular and transgranular fracture mode in zirconium-doped NiAl. The NiAl matrix was severely depleted of the solutes molybdenum and zirconium. Small Mo-rich precipitates, detected in the matrix and grain boundaries, are likely to contribute to the significant increase in the room-temperature yield stress of microalloyed NiAl through a precipitation hardening mechanism.

Jayaram, R. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineering; Miller, M.K. [Oak Ridge National Lab., TN (United States)

1995-03-01T23:59:59.000Z

130

Isotopic identification of surface site transfer on Ni/Al/sub 2/O/sub 3/ catalysts  

SciTech Connect

Isotope labeling with temperature-programmed reaction (TPR) for CO hydrogenation was used to separate two distinct CO adsorption sites on a Ni/Al/sub 2/O/sub 3/ catalysts. One site is Ni metal and has the higher activity for CO hydrogenation. The less-reactive CO is on the Al/sub 2/O/sub 3/ support. Only the Ni metal is occupied at 300 K, and transfer for CO between the two sites occurs at higher temperatures. In the presence of adsorbed H/sub 2/, CO that was adsorbed on the Ni metal moved to the Al/sub 2/O/sub 3/ support. This is an activated process, and the only pathway to occupy the Al/sub 2/O/sub 3/ sites is by adsorption on the Ni. The reverse transfer from Al/sub 2/O/sub 3/ to Ni occurs if some of the H/sub 2/ is desorbed; surface hydrogen inhibits this reverse process. These results show that during a typical TPR experiment, transfer between sites competes with reaction.

Gugla, P.G.; Bailey, K.M.; Falconer, J.L.

1988-07-28T23:59:59.000Z

131

Thermodynamic properties and stability of AlF-bearing titanite CaTiOSiO4–CaAlFSiO4  

Science Journals Connector (OSTI)

Calorimetric and experimental data on AlF-bearing titanite are presented that yield thermodynamic properties of CaAlFSiO4, as well as activity-composition relations of binary titanite CaTiOSiO4–CaAlFSiO4. The hea...

Ulrike Troitzsch; David J. Ellis

2002-02-01T23:59:59.000Z

132

Micro-Raman spectroscopic study of nanolaminated Ti{sub 5}Al{sub 2}C{sub 3}  

SciTech Connect

Micro-Raman spectroscopic study and lattice dynamics calculations were conducted to study a recently identified layered ternary carbide, Ti{sub 5}Al{sub 2}C{sub 3}. The experimental Raman shifts were remarkably consistent with the calculated values. Polarized Raman spectrum was collected in the polycrystalline sample, which confirmed the theoretical symmetry assignment of the Raman modes. In addition, the atomic vibrations of the peaks at 192?cm{sup ?1}, 311?cm{sup ?1}, and 660?cm{sup ?1} were identified to be the combination of the counterparts in Ti{sub 2}AlC and Ti{sub 3}AlC{sub 2}.

Zhang, H.; Li, Z. J. [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Wang, X. H. [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Xiang, H. M.; Zhou, Y. C, E-mail: yczhou714@gmail.com [Science and Technology of Advanced Functional Composite Laboratory, ARIMPT, No.1 South Dahongmen Road, Beijing 100076 (China)

2014-03-31T23:59:59.000Z

133

Model for projectile fragmentation: case study for Ni on Ta, Be and Xe on Al  

E-Print Network (OSTI)

For projectile fragmentation we work out details of a model whose origin can be traced back to the Bevalac era. The model positions itself between the phenomenological EPAX parametrization and microscopic transport models like "Heavy Ion Phase Space Exploration Model" (HIPSE) and antisymmetrised molecular dynamics(AMD). We apply the model to some recent data of projectile fragmentation of Ni on Ta and Be at beam energy 140 MeV/nucleon and some older data of Xe on Al at beam energy 790 MeV/nucleon. Reasonable values of cross-sections for various composites populated in the reactions are obtained.

S. Mallik; G. Chaudhuri; S. Das Gupta

2010-12-30T23:59:59.000Z

134

Surface characterization and mechanical property evaluation of thermally oxidized Ti-6Al-4V  

SciTech Connect

The present study concerns development of a thin and adherent oxide film on the surface of Ti-6Al-4V by thermal oxidation. Thermal oxidation was carried out over a range of temperature between 400 to 600 deg. C and a time from 25 h to 60 h. A detailed characterization of the surface and cross section of the oxidized surface was carried out by optical/scanning electron microscopy and X-ray diffraction techniques. Finally, the mechanical properties of the oxidized surface in terms of microindentation hardness and wear resistance were evaluated as a function of oxidation parameters. Surface oxidation of Ti-6Al-4V at 600 deg. C for 36 h offered a defect free oxide scale with improved hardness and wear resistance.

Biswas, Amit [Department of Metal. and Maters. Engg., I. I. T. Kharagpur, W. B. - 721302 (India); Dutta Majumdar, Jyotsna, E-mail: jyotsna@metal.iitkgp.ernet.in [Department of Metal. and Maters. Engg., I. I. T. Kharagpur, W. B. - 721302 (India)

2009-06-15T23:59:59.000Z

135

Cold compaction study of Armstrong Process Ti-6Al-4V powders  

SciTech Connect

This work investigates the cold compaction behavior of Ti-6Al-4V powders produced by Armstrong Process . As-received as well as milled powders were characterized and these powders were uniaxially die-pressed at designated pressures up to 690 MPa to form disk samples with different aspect ratios. Samples with high aspect ratio exhibited non-uniform density along the pressing axis and the density distribution is in consistent with the result predicted by finite element analysis. The linear regression analysis on the experimental density data can be used to predict density of compacts with different aspect ratios. In the studied pressure range, an empirical powder compaction equation represents the green density pressure relationship very well for both the as-received and 1-hr milled Armstrong Ti-6Al-4V powders.

Chen, Wei [ORNL; Yamamoto, Yukinori [ORNL; Peter, William H [ORNL; Gorti, Sarma B [ORNL; Sabau, Adrian S [ORNL; Clark, Michael B [ORNL; Nunn, Stephen D [ORNL; Kiggans, Jim [ORNL; Blue, Craig A [ORNL; Fuller, Brian [International Titanium Powder; Akhtar, Kamal [International Titanium Powder

2011-01-01T23:59:59.000Z

136

The early stages of solid-state reactions in Ti/Al multilayer films  

SciTech Connect

The authors have investigated the solid-state reaction of Ti/Al multilayer films by x-ray diffraction (XRD) and differential scanning calorimetry (DSC), with focus on the early stages of the reaction provided by samples with pair thicknesses in the range 5--40 nm. This reaction, which results in formation of TiAl{sub 3} with metastable L1{sub 2} structure, can be modeled by a nucleation and growth process on the basis of the Johnson-Mehl-Avrami theory, with a reaction-order parameter n {approx} 1. These observations indicate the significance of nucleation barriers even at early stages of solid-state reactions, and suggests that the phenomena of phase selection and formation of metastable phases can result from the presence of nucleation barriers.

Michaelsen, C.; Woehlert, S.; Bormann, R. [GKSS Research Center, Geesthacht (Germany). Inst. for Materials Research; Barmak, K. [Lehigh Univ., Bethlehem, PA (United States). Dept. of Materials Science and Engineering

1996-12-31T23:59:59.000Z

137

Consolidation Process in Near Net Shape Manufacturing of Armstrong CP-Ti/Ti-6Al-4V Powders  

SciTech Connect

This paper summarizes our recent efforts to develop the manufacturing technologies of consolidated net-shape components by using new low-cost commercially pure titanium (CP-Ti) and Ti-6Al-4V alloy powders made by the Armstrong process. Fabrication processes of net shape/ near net shape components, such as uniaxial die-pressing, cold isostatic pressing (CIP), sintering, roll compaction and stamping, have been evaluated. The press-and-sinter processing of the powders were systematically investigated in terms of theoretical density and microstructure as a function of time, pressure, and temperature. Up to 96.4% theoretical density has been achieved with the press-and-sinter technology. Tensile properties of the consolidated samples exhibit good ductility as well as equivalent yield/ultimate tensile strengths to those of fully consolidate materials, even with the presence of a certain amount of porosity. A consolidation model is also under development to interpret the powder deformation during processing. Net shape components made of the Armstrong powder can successfully be fabricated with clearer surface details by using press-and-sinter processing.

Yamamoto, Yukinori [ORNL; Kiggans, Jim [ORNL; Clark, Michael B [ORNL; Nunn, Stephen D [ORNL; Sabau, Adrian S [ORNL; Peter, William H [ORNL

2010-01-01T23:59:59.000Z

138

Synthesis of nanostructured multiphase (Ti,Al)N/a-Si3N4 thin films using dense plasma focus device  

Science Journals Connector (OSTI)

A 2.3 kJ pulsed plasma focus device was used to prepare thin films of nc-(Ti,Al)N/a-Si3N4 at room temperature. The plasma focus device, fitted with copper anode encapsulated with Ti0.5Al0.5 anode, was operated with nitrogen as the filling gas. Films were deposited with various number of focus shots, at 90 mm from top of the anode and at zero angular position with respect to anode axis. XRD patterns show the growth of polycrystalline (Ti,Al)N thin films with orientations in the (1 1 1), (2 0 0), (2 2 0) and (3 1 1) crystallographic planes. Behavior of lattice constant, grain size and film roughness of deposited film as a function of variation in number of focus shots is discussed. SEM micrographs of film deposited with 15 number of focus shots exhibit well-developed net like structure of nc-(Ti,Al)N/a-Si3N4 and possibly nc-(Ti,Al)N/a-Si3N4/a-AlN or nc-TiN/a-Si3N4/a-AlN. Surface Roughness ranging 64 nm to 89 nm was also observed.

Tousif Hussain; R. Ahmad; Nida Khalid; Z.A. Umar; A. Hussnain

2011-01-01T23:59:59.000Z

139

Magnetic susceptibility contributions and electronic density of states in (Ti,Zr)100?x(Ni,Cu)x metallic glasses and crystalline compounds  

Science Journals Connector (OSTI)

Available experimental data on the magnetic susceptibility of melt-quenched amorphous TE-TL alloys (TE=Ti or Zr; TL=Ni or Cu) and the corresponding crystalline counterparts are reviewed. In order to analyze the composition dependence of the magnetic susceptibility in these systems, the individual contributions (element-resolved Langevin diamagnetic, Van Vleck and Pauli spin susceptibility, as well as the Landau susceptibility) were determined directly by theoretical calculations for these TE-TL alloys in a face-centered-cubic (fcc) structure. The total susceptibility, both experimental and calculated, was found to decrease with increasing TL content up to about 60–70at.%. This variation was mainly ascribed to corresponding changes of the Van Vleck contribution and the spin susceptibility. The composition dependence of the latter term is in line with the previously established trend of variation of the density of states at the Fermi level n(EF) upon alloying. As in previous reports on electronic band-structure calculations, it turned out that to get agreement with experiments on n(EF) in amorphous Zr-Ni alloys, at least some partial chemical ordering should be taken into account. Available experimental data of crystalline stoichiometric Zr-Ni compounds beyond 70at.% Ni show a gradual increase of the Pauli susceptibility, indicating an approach toward the onset of ferromagnetic order observed previously experimentally around 90at.% Ni in amorphous Zr-Ni alloys. The susceptibility calculations for fcc Ti-Ni and Zr-Ni alloys indicate a strong increase of the spin susceptibility component above 70at.% Ni, and the calculated Stoner enhancement for Zr10Ni90 fulfills the condition of ferromagnetism in agreement with the experimental observation.

S. Mankovsky, I. Bakonyi, and H. Ebert

2007-11-06T23:59:59.000Z

140

Properties of two-phase intermetallic (Ti, Nb){sub 3} (Al, Si) + (Ti, Nb){sub 5} (Si, Al){sub 3} P/M bulk and sheet material  

SciTech Connect

Intermetallic Ti-based alloy powder with nominal composition Ti 23.5Al5.5Si 10 Nb(at.%) was produced by argon gas atomization. This dual phase alloy is composed of the {alpha}{sub 2}-(Ti, Nb){sub 3} (Al,Si)-matrix phase and a eutectic mixture of {alpha}{sub 2}-(Ti, Nb){sub 3}(Al, Si) + {xi}-(Ti, Nb){sub 5} (Si, Al){sub 3}. The powder was compacted by hot isostatic pressing, subsequently hot rolled into sheets, and heat treated. The microstructures of the HIPed compacts and of the sheet materials were metallographically characterized and correlated with tensile properties at temperatures between 20 and 1,000 C. Due to networks of the brittle {xi}-silicide phase, the HIPed state showed no ductility at 20 C. Break-down of the silicide network during rolling led to an improved ductility at 20 C. After post rolling annealing, the yield strengths at 20 and 700 C were between 750--490 MPa and 700--420 MPa for specimens taken parallel and perpendicular to the rolling direction, respectively. These values are considerably higher than those reported for {gamma}-TiAl sheets. At 1,000 C the sheet material could be superplastically deformed.

Gerling, R.; Oehring, M.; Schimansky, F.P. [GKSS-Forschungszentrum, Geesthacht (Germany)] [GKSS-Forschungszentrum, Geesthacht (Germany); Bartels, A. [TU Hamburg-Harburg (Germany)] [TU Hamburg-Harburg (Germany); Clemens, H. [Plansee Aktiengesellschaft, Reutte (Austria). Technology Center] [Plansee Aktiengesellschaft, Reutte (Austria). Technology Center

1997-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "ni ti al" 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

COMPARISON OF THE CORROSION BEHAVIOR OF A BULK AMORPHOUS METAL, Zr41.2Ti13.8Cu12.5Ni10Be22.5,  

E-Print Network (OSTI)

COMPARISON OF THE CORROSION BEHAVIOR OF A BULK AMORPHOUS METAL, Zr41.2Ti13.8Cu12.5Ni10Be22 exhibit excellent corrosion resistance (4­7), which has been explained in terms of their structural researchers attribute "good corrosion resistance" to the entire class of amorphous metals. It is this point

Ritchie, Robert

142

Temperature dependent junction capacitance-voltage characteristics of Ni embedded TiN/SiO{sub 2}/p-Si metal–insulator–semiconductor structure  

SciTech Connect

This work presents the junction capacitance–voltage characteristics of highly textured/epitaxial Ni nanoparticle embedded in TiN matrix (TiN(Ni)) metal-insulator-semiconductor TiN(Ni)/SiO{sub 2}/p-Si (100) heterojunction in the temperature range of 10–300?K. This heterojunction behaves as metal-semiconductor junction with unavoidable leakage through native oxide SiO{sub 2} layer. The clockwise hysteresis loop has been observed in the capacitance-voltage characteristics measured at various frequencies mainly due to presence of trap centers at the TiN(Ni)/SiO{sub 2} interface and these are temperature dependent. The spin-dependent trap charge effect at the interface influences the quadratic nature of the capacitance with magnetic field. The junction magnetocapacitance (JMC) is observed to be dependent on both temperature and frequency. The highest JMC of this heterojunction has been observed at 200?K at higher frequencies (100?kHz–1?MHz). It is found that there is not much effect of band structure modification under magnetic field causing the JMC.

Panda, J.; Nath, T. K., E-mail: tnath@phy.iitkgp.ernet.in [Department of Physics and Meteorology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302 (India); Chattopadhyay, S. [Department of Physics and Meteorology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302 (India); Amity Institute of Nano Technology, Amity University, Sector-125, Noida, Uttar Pradesh 201313 (India)

2013-12-14T23:59:59.000Z

143

Evaluation of Pre-sulfided NiMo/?-Al2O3 for Hydrodeoxygenation of Microalgae Oil to Produce Green-diesel  

Science Journals Connector (OSTI)

Evaluation of Pre-sulfided NiMo/?-Al2O3 for Hydrodeoxygenation of Microalgae Oil to Produce Green-diesel ... Energy Fuels, Just Accepted Manuscript ...

Lin Zhou; Adeniyi Lawal

2014-12-05T23:59:59.000Z

144

Metal-insulator transitions induced by doping in LaNiO{sub 3}: LaNi{sub 0.95}M{sub 0.05}O{sub 3} (M = Mo, W, Sb, Ti, Cu, Zn) perovskites  

SciTech Connect

Structural characterization and electronic properties of the LaNi{sub 0.95}M{sub 0.05}O{sub 3} (M = Mo, W, Sb, Ti, Cu, Zn) perovskite-like system are reported. These compounds can be regarded as being derived from LaNiO{sub 3} by partial substitution of Ni{sup 3+} in this material by M{sup 6+}, M{sup 5+}, M{sup 4+}, or M{sup 2+} formal cations, with a partial reduction of Ni{sup 3+} to Ni{sup 2+} taking place. X-ray powder diffraction data were analyzed by means of the Rietveld method and show that all the title materials present perovskite-type structure with a rhombohedral (S.G. R{bar 3}c) or orthorhombic (S.G. Pbnm) symmetry, depending on the nature of the M cation. In all cases, Ni and M cations are placed at random in octahedral B-sites of perovskite structure. Electrical resistivity measurements (four probe method) show metal-to-insulator (M-I) transitions for M = Mo, W, Ti, Cu, Zn at temperatures of about 50K and a semiconductor behavior for the Sb sample in the whole temperature range explored. Magnetic susceptibility measurements show the presence of weak ferromagnetic interactions for M = Sb and Pauli paramagnetism for the remaining compounds.

Alvarez, I.; Veiga, M.L.; Pico, C. [Univ. Complutense, Madrid (Spain)] [Univ. Complutense, Madrid (Spain)

1998-03-01T23:59:59.000Z

145

Composition, morphology and mechanical properties of sputtered TiAlN coating  

SciTech Connect

TiAlN coating was deposited on the tungsten carbide cutting tool by using DC magnetron sputtering system to study the influence of substrate bias and nitrogen flow rate on the composition, morphology and mechanical properties. The negatively substrate bias and nitrogen flow rate was varied from about ?79 to ?221 V and 30 sccm to 72 sccm, respectively. The coating composition and roughness were characterized by using SEM/EDX and Atomic Force Microscopy (AFM), respectively. The dynamic ultra micro hardness tester was used to measure the mechanical properties. The coating hardness increases to about 10-12 GPa with an increase of the negatively substrate bias up to ? 200 V and it tend to decrease with an increase in nitrogen flow rate up to 70 sccm. The increase of hardness follows the increase of Ti and N content and rms coating roughness.

Budi, Esmar, E-mail: esmarbudi@unj.ac.id [Department of Physics, Faculty of Science and Mathematics, Universitas Negeri Jakarta, Jl. Pemuda No. 10, Jakarta 13220 (Indonesia); Razali, M. Mohd. [Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka, Karung Berkunci No. 1752 Pejabat Pos Durian Tunggal 76109 Melaka (Malaysia); Nizam, A. R. Md. [Faculty of Manufacturing Engineering, UniversitiTeknikal Malaysia Melaka, Karung Berkunci No. 1752 Pejabat Pos Durian Tunggal 76109 Melaka (Malaysia)

2014-03-24T23:59:59.000Z

146

In situ transmission electron microscopy investigation of the interfacial reaction between Ni and Al during rapid heating in a nanocalorimeter  

SciTech Connect

The Al/Ni formation reaction is highly exothermic and of both scientific and technological significance. In this report, we study the evolution of intermetallic phases in this reaction at a heating rate of 830 K/s. 100-nm-thick Al/Ni bilayers were deposited onto nanocalorimeter sensors that enable the measurement of temperature and heat flow during rapid heating. Time-resolved transmission electron diffraction patterns captured simultaneously with thermal measurements allow us to identify the intermetallic phases present and reconstruct the phase transformation sequence as a function of time and temperature. The results show a mostly unaltered phase transformation sequence compared to lower heating rates.

Grapes, Michael D., E-mail: mgrapes1@jhu.edu, E-mail: david.lavan@nist.gov, E-mail: weihs@jhu.edu [Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Material Measurement Laboratory, Materials Measurement Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); LaGrange, Thomas; Reed, Bryan W.; Campbell, Geoffrey H. [Lawrence Livermore National Laboratory, Materials Science and Technology Division, Livermore, California 94550 (United States); Woll, Karsten [Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Institute of Applied Materials, Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen (Germany); LaVan, David A., E-mail: mgrapes1@jhu.edu, E-mail: david.lavan@nist.gov, E-mail: weihs@jhu.edu [Material Measurement Laboratory, Materials Measurement Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Weihs, Timothy P., E-mail: mgrapes1@jhu.edu, E-mail: david.lavan@nist.gov, E-mail: weihs@jhu.edu [Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States)

2014-11-01T23:59:59.000Z

147

Temperature dependence of dynamic Young's modulus and internal friction in three plasma sprayed NiCrAlY coating alloys  

E-Print Network (OSTI)

TEMPERATURE DEPENDENCE OF DYNAM'IIC YOUNG'S MODULUS AND INTERNAL FRICTION IN THREE PLASMA SPRAYED NiCrAlY COATING -ALLOYS A Thesis LLOYD STEVEN COOK Submitted to the 08ice of Graduate Studies of Texas AE M University in part. al full...'illment of the requirement for the degree of MASTER OF SCIENCE August 1989 Itiajor Subject: l'dechanical Engineering TEMPERATURE DEPENDENCE OF DYNAMIC YOUNG'S MODULUS AND INTERNAL FRICTION IN THREE PLASMA SPRAYED NiCrAIY COATING ALLOYS A Thesis by LLOYD STEVEN COOK...

Cook, Lloyd Steven

1989-01-01T23:59:59.000Z

148

Effect of aluminum content on synthesis of Ti2AlC and Ti3AlC2 during treatment in a high-energy mill and hot pressing  

Science Journals Connector (OSTI)

Treatment of initial powders of titanium, carbon and aluminum in a high-energy mill and pressure sintering are used for...2AlC and Ti3AlC2 ceramics. The effect of the content of aluminum and of the sintering temp...

Jianfeng Zhu; Guoquan Qi; Fen Wang; Haibo Yang; Ying Li

2011-05-01T23:59:59.000Z

149

Amorphous and crystalline phase formation in Ni/Al multilayer thin films  

SciTech Connect

The authors have investigated reactive phase formation in magnetron sputter-deposited Ni/Al multilayer films with a 1:3 molar ratio and various periodicities ranging from 320 nm to a codeposited film with an effective periodicity of zero. The films were studied by x-ray diffraction, differential scanning calorimetry, electrical resistance measurements, and transmission electron microscopy. The authors find that a reaction which results in the formation of an amorphous phase has taken place during the multilayer deposition process. This reaction substantially reduces the driving force for subsequent reactions and explains why nucleation kinetics become important for these reactions. The mode of transformation for a film with 10 nm periodicity was investigated, in detail, by applying the Johnson-Mehl-Avrami analysis to data obtained from isothermal and constant heating rate differential scanning calorimetry, in combination with electron microscopy studies of the transformation microstructure.

Lucadamo, G.; Barmak, K. [Lehigh Univ., Bethlehem, PA (United States). Dept. of Materials Science and Engineering; Michaelsen, C. [GKSS Research Center, Geesthacht (Germany). Inst. of Materials Research

1996-12-31T23:59:59.000Z

150

Performance Characteristics of Fluidized Bed Syngas Methanation over Ni-Mg/Al2O3 Catalyst  

Science Journals Connector (OSTI)

Abstract The performance characteristics of isothermal fluidized bed syngas methanation for substitute natural gas is investigated over a self-made Ni-Mg/Al2O3 catalyst. Via atmospheric methanation in a laboratory fluidized bed reactor it was clarified that the CO conversion varied in 5% when changing the space velocity in 40-120 L · g- 1 · h- 1 but the conversion increased obviously by raising the superficial gas velocity from 4 to 12.4 cm · s- 1. The temperature 823 K is suitable for syngas methanation while obvious deposition of uneasy-oxidizing C? occurs on the catalyst at temperatures around 873 K. From kinetic aspect, the lowest reaction temperature is suggested to be 750 K when the space velocity is 60 L · g- 1 · h- 1. Raising the H2/CO ratio of the syngas increased proportionally the CO conversion and CH4 selectivity, showing that at enough high H2/CO ratios the active sites on the catalyst are sufficient for CO adsorption and in turn the reaction with H2 for forming CH4. Introducing CO2 into the syngas feed increased H2 consumption but suppressed water gas shift and Boudouard reactions. The ratio of CO2/CO in syngas should be better below 0.52 because varying the ratio from 0.52 to 0.92 resulted in negligible increases in the H2 conversion and CH4 selectivity but decreased the CH4 yield. Introducing steam into the feed gas affected little the CO conversion but decreased the selectivity to CH4. The tested Ni-Mg/Al2O3 catalyst manifested good stability in structure and activity even in syngas containing water vapor.

Jiao Liu; Dianmiao Cui; Jian Yu; Fabing Su; Guangwen Xu

2014-01-01T23:59:59.000Z

151

Effects of processing on texture, microstructure and related properties of TiAl alloys  

SciTech Connect

Depending on factors such as processing conditions, stoichiometry and initial microstructure a variety of different textures has been found in TiAl alloys. They give insight into the origin of the generation of preferred orientations during solidification and recrystallization and by rotation of orientations during deformation. A comparison of measured and simulated textures on the basis of current models of polycrystal deformation leads to general conclusions about the crystallography of slip and on the strength of the different slip systems. The knowledge of texture is profitable for an understanding as well as for an explanation of the anisotropy of mechanical properties such as elastic constants, plastic behavior and fracture parameters.

Mecking, H.; Hartig, C. [Technical Univ. Hamburg-Harburg, Hamburg (Germany)

1995-12-31T23:59:59.000Z

152

Time-dependent stress concentration and microcrack nucleation in TiAl  

SciTech Connect

Localized stress evolution associated with the interaction of slip or twinning with an interface is treated by means of a superposition of the internal loading of a crystalline subsystem by dynamic dislocation pile-up and the stress relaxation by climb of interfacial dislocations. The peak value of a stress concentration factor depends on both the angular function that includes the effect of mode mixity and the ratio of characteristic times for stress relaxation and internal loading. The available experimental data on orientation and strain rate dependences of interfacial fracture mode in polysynthetically twinned TiAl crystals are discussed in view of the theoretical concepts presented in this paper.

Yoo, M.H. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Division

1995-12-31T23:59:59.000Z

153

Improved Hydrogen Storage Kinetics of Nanoconfined NaAlH4 Catalyzed with TiCl3 Nanoparticles  

Science Journals Connector (OSTI)

Improved Hydrogen Storage Kinetics of Nanoconfined NaAlH4 Catalyzed with TiCl3 Nanoparticles ... We demonstrate that NaAlH4 confined within the nanopores of a titanium-functionalized metal–organic framework (MOF) template MOF-74(Mg) can reversibly store hydrogen with minimal loss of capacity. ...

Thomas K. Nielsen; Marek Polanski; Dariusz Zasada; Payam Javadian; Flemming Besenbacher; Jerzy Bystrzycki; Jørgen Skibsted; Torben R. Jensen

2011-03-29T23:59:59.000Z

154

High-Temperature Galling Characteristics of Ti-6Al-4V with and without Surface Treatments  

SciTech Connect

Galling is a severe form of surface damage in metals and alloys that typically arises under relatively high normal force, low-sliding speed, and in the absence of effective lubrication. It can lead to macroscopic surface roughening and seizure. The occurrence of galling can be especially problematic in high-temperature applications like diesel engine exhaust gas recirculation system components and adjustable turbocharger vanes, because suitable lubricants may not be available, moisture desorption promotes increased adhesion, and the yield strength of metals decreases with temperature. Oxidation can counteract these effects to some extent by forming lubricative oxide films. Two methods to improve the galling resistance of titanium alloy Ti-6Al-4V were investigated: (a) applying an oxygen diffusion treatment, and (b) creating a metal-matrix composite with TiB2 using a high-intensity infrared heating source. A new, oscillating three-pin-on-flat, high-temperature test method was developed and used to characterize galling behavior relative to a cobalt-based alloy (Stellite 6B ). The magnitude of the oscillating torque, the surface roughness, and observations of surface damage were used as measures of galling resistance. Owing to the formation of lubricative oxide films, the galling resistance of the Ti-alloy at 485o C, even non-treated, was considerably better than it was at room temperature. The IR-formed composite displayed reduced surface damage and lower torque than the substrate titanium alloy.

Blau, Peter Julian [ORNL; ERDMAN III, DONALD L [ORNL; Ohriner, Evan Keith [ORNL; Jolly, Brian C [ORNL

2011-01-01T23:59:59.000Z

155

A transmission electron microscopy study of the deformation behavior underneath nanoindents in nano-scale Al-TiN multilayered composites  

SciTech Connect

Nano-scale multilayered Al-TiN composites were deposited with DC magnetron sputtering technique in two different layer thickness ratios - Al:TiN = 1:1 and Al:TiN = 9:1. The Al layer thickness varied from 2 nm to 450 nm. The hardness of the samples was tested by nanoindentation using a Berkovich tip. Cross-sectional Transmission Electron Microscopy (TEM) was carried out on samples extracted with Focused Ion Beam (FIB) from below the nanoindents. This paper presents the results of the hardness tests in the Al-TiN multilayers with the two different thickness ratios and the observations from the cross-sectional TEM studies of the regions underneath the indents. These studies showed remarkable strength in the multilayers, as well as some very interesting deformation behavior in the TiN layers at extremely small length scales, where the hard TiN layers undergo co-deformation with the Al layers.

Bhattacharyya, Dhriti [Los Alamos National Laboratory; Mara, Nathan A [Los Alamos National Laboratory; Dickerson, Patricia O [Los Alamos National Laboratory; Misra, Amit [Los Alamos National Laboratory; Hoagland, R G [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

156

Ru/Ni/MgAl2O4 catalysts for steam reforming of methane: effects of Ru content on self-activation property  

Science Journals Connector (OSTI)

The effects of Ru on the self-reducibility of Ru-doped Ni/MgAl2O4 catalysts, which do not need pre-reduction treatment with H2, were investigated in the steam reforming of methane (SRM). The Ru-promoted Ni/MgAl2O

Seung-Chan Baek; Ki-Won Jun; Yun-Jo Lee; Jae Dong Kim…

2012-04-01T23:59:59.000Z

157

Investigating surface roughness, material removal rate and corrosion resistance in PMEDM of ?-TiAl intermetallic  

Science Journals Connector (OSTI)

Titanium aluminide intermetallics offer an attractive combination of low density and good oxidation, corrosion and ignition resistance with unique mechanical properties. In this study two series of machining tests are designed. Firstly the powder mixed electrical discharge machining (PMEDM) of ?-TiAl by means of different powders such as aluminum, chrome, silicon carbide, graphite and iron is performed to investigate the output characteristics of surface roughness and topography, material removal rate (MRR), electrochemical corrosion resistance of machined samples and also the machined surfaces are investigated by means of EDS and XRD analyses. Secondly after selection the aluminum powder as the most appropriate kind of powder, the current, pulse on time, powder size and powder concentration are changed in different levels for overall comparison between EDM and PMEDM output characteristics. In the first setting of input machining parameters, aluminum powder improves the surface roughness of TiAl sample about 32% comparing with EDM case and also aluminum particles with the size of 2 ?m, in the second setting of input parameters lead to 54% enhancement of MRR comparing with EDM case. The electrochemical corrosion results show that, corrosion resistance of the samples which are machined by graphite and chrome powders respectively are about three and two times more than the sample which is machined without powder.

Behzad Jabbaripour; Mohammad Hossein Sadeghi; Mohammad Reza Shabgard; Hossein Faraji

2013-01-01T23:59:59.000Z

158

Hydrogen production by methane steam reforming over Ru supported on Ni–Mg–Al mixed oxides prepared via hydrotalcite route  

Science Journals Connector (OSTI)

Abstract Catalytic performance of Ru/NixMg6?xAl2 800 800 mixed oxides, with x = 2, 4 and 6, x being the molar ratio, towards Methane Steam Reforming, was studied. NixMg6?xAl2 800 oxide, used as support, was prepared via hydrotalcite route. It was thermally stabilized at 800 °C, impregnated with 0.5 wt.% ruthenium using ruthenium (III) nitrosyl nitrate Ru(NO) (NO3)3 precursor and then calcined again at 800 °C under an air flow. Ruthenium impregnation significantly enhanced the reactivity of the oxides in Methane Steam Reforming. In fact, it was found, that even with a low ruthenium content (0.5 wt.%), ruthenium oxide particles are formed but are well dispersed over the surface of the oxide NixMg6?xAl2 800. Ru/Ni6Al2 800 800 showed better catalytic performances, towards Methane Steam Reforming, than ruthenium impregnated on the two other supports. Indeed, nickel content is higher in Ni6Al2 800 than in the other studied supports and therefore the probability of Ni–Ru interaction should be greater and consequently catalytic performances could be improved.

Mira Nawfal; Cédric Gennequin; Madona Labaki; Bilal Nsouli; Antoine Aboukaïs; Edmond Abi-Aad

2014-01-01T23:59:59.000Z

159

The formation of double-row oxide stripes during the initial oxidation of NiAl(100)  

SciTech Connect

The initial growth of ultrathin aluminum oxide film during the oxidation of NiAl(100) was studied with scanning tunneling microscopy. Our observations reveal that the oxide film grows initially as pairs of a double-row stripe structure with a lateral size equal to the unit cell of ?-Al{sub 2}O{sub 3}. These double-row stripes serve as the very basic stable building units of the ordered oxide phase for growing thicker bulk-oxide-like thin films. It is shown that the electronic properties of these ultrathin double-row stripes do not differ significantly from that of the clean NiAl surface; however, the thicker oxide stripes show a decreased conductivity.

Qin, Hailang; Zhou, Guangwen [Department of Mechanical Engineering and Multidisciplinary Program in Materials Science and Engineering, State University of New York, Binghamton, New York 13902 (United States)] [Department of Mechanical Engineering and Multidisciplinary Program in Materials Science and Engineering, State University of New York, Binghamton, New York 13902 (United States)

2013-08-28T23:59:59.000Z

160

Analysis of defect generation in Ti–6Al–4V parts made using powder bed fusion additive manufacturing processes  

Science Journals Connector (OSTI)

Abstract Ti–6Al–4V parts made using additive manufacturing processes such as selective laser melting (SLM) and electron beam melting (EBM) are subject to the inclusion of defects. This study purposely fabricated Ti–6Al–4V samples with defects by varying process parameters from the factory default settings in both SLM and EBM systems. Process parameters are classified according to their tendency to create certain types of porosity. Finally, defect characteristics are discussed with respect to defect generation mechanisms; and effective process windows for SLM and EBM system are discussed.

Haijun Gong; Khalid Rafi; Hengfeng Gu; Thomas Starr; Brent Stucker

2014-01-01T23:59:59.000Z

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


161

E-Print Network 3.0 - aleaciones cu-zn-al estabilidad Sample...  

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C2, suppl6mentau Journal de Physique 111,Volume 5, f6vrier 1995 Summary: The shape memory alloys which are industrially used are based upon NiTi, CuZnAl and CuAlNi to which...

162

Laser cladding Al-Si/Al2O3-TiO2 composite coatings on AZ31B magnesium alloy  

Science Journals Connector (OSTI)

To improve the wear resistance and corrosion resistance of magnesium alloys, a 5 kW continuous wave CO2 laser was used to investigate the laser surface cladding on AZ31B magnesium alloys with Al-Si/...2O3 -TiO2.....

Zeqin Cui ???; Hongwei Yang…

2012-12-01T23:59:59.000Z

163

Effect of thermally stable Cu- and Mg-rich aluminides on the high temperature strength of an AlSi12CuMgNi alloy  

SciTech Connect

The internal architecture of an AlSi12CuMgNi piston alloy, revealed by synchrotron tomography, consists of three dimensional interconnected hybrid networks of Cu-rich aluminides, Mg-rich aluminides and eutectic/primary Si embedded in an ?-Al matrix. The strength at room temperature and at 300°C is studied as a function of solution treatment time at 490°C and compared with results previously reported for an AlSi12Ni alloy. The addition of 1 wt% Cu and 1 wt% Mg to AlSi12CuMgNi increases the room temperature strength by precipitation hardening while the strength at 300°C is similar for both alloys in as-cast condition. The strength of AlSi12CuMgNi decreases with solution treatment time and stabilizes at 4 h solution treatment. The effect of solution treatment time on the strength of the AlSi12CuMgNi alloy is less pronounced than for the AlSi12Ni alloy both at room temperature and at 300°C. - Highlights: • The 3D microstructure of AlSi12CuMgNi is revealed by synchrotron tomography. • An imaging analysis procedure to segment phases with similar contrasts is presented. • 1 wt% Cu and Mg results in the formation of 3D networks of rigid phases. • AlSi12CuMgNi is stronger than AlSi12Ni owing to the stability of the 3D networks.

Asghar, Z., E-mail: zhdasghar@yahoo.com [Materials Division, Directorate of Technology, PINSTECH, P. O. Nilore, Islamabad (Pakistan); Vienna University of Technology, Institute of Materials Science and Technology, Karlsplatz 13/308, A-1040 Vienna (Austria); Requena, G. [Vienna University of Technology, Institute of Materials Science and Technology, Karlsplatz 13/308, A-1040 Vienna (Austria); Zahid, G.H.; Rafi-ud-Din [Materials Division, Directorate of Technology, PINSTECH, P. O. Nilore, Islamabad (Pakistan)

2014-02-15T23:59:59.000Z

164

The investigation of die-pressing and sintering behavior of ITP CP-Ti and Ti-6Al-4V powders  

SciTech Connect

This paper investigated the die-pressing and sintering behavior of the low-cost CP-Ti and Ti-6Al- 4V powders made by the Armstrong Process . The Armstrong powders have an irregular coral like, dendritic morphology, with a dendrite size of approximately 2-5 m. As-received as well as milled powders were uniaxially pressed at designated pressures up to 690 MPa to form disk samples with different aspect ratios. In the studied pressure range, an empirical powder compaction equation was applied to linearize the green density pressure relationship, and powder compaction parameters were obtained. The Armstrong Ti-64 powder exhibited a significantly higher sinterability than the CP-Ti powder. This was explained to be due to the higher diffusivity of V at the sintering temperature. The Ti-64 samples with a green density of 71.0% increased to 99.6% after sintering at 1300oC for 1 hour. An ex-situ technique was used to track the powder morphology change before and after sintering.

Chen, Wei [ORNL; Yamamoto, Yukinori [ORNL; Peter, William H [ORNL; Clark, Michael B [ORNL; Nunn, Stephen D [ORNL; Kiggans, Jim [ORNL; Muth, Thomas R [ORNL; Blue, Craig A [ORNL; Williams, James C [Ohio State University; Fuller, Brian [International Titanium Powder; Akhtar, Kamal [International Titanium Powder

2012-01-01T23:59:59.000Z

165

Role of interface structure and chemistry in resistive switching of NiO nanocrystals on SrTiO{sub 3}  

SciTech Connect

Nickel oxide (NiO) nanocrystals epitaxially grown on (001) strontium titanate (SrTiO{sub 3}) single crystal substrates were characterized to investigate interface morphology and chemistry. Aberration corrected high angle annular dark field scanning transmission electron microscopy reveals the interface between the NiO nanocrystals and the underlying SrTiO{sub 3} substrate to be rough, irregular, and have a lower average atomic number than the substrate or the nanocrystal. Energy dispersive x-ray spectroscopy and electron energy loss spectroscopy confirm both chemical disorder and a shift of the energy of the Ti L{sub 2,3} peaks. Analysis of the O K edge profiles in conjunction with this shift, implies the presence of oxygen vacancies at the interface. This sheds light into the origin of the previously postulated minority carriers’ model to explain resistive switching in NiO [J. Sullaphen, K. Bogle, X. Cheng, J. M. Gregg, and N. Valanoor, Appl. Phys. Lett. 100, 203115 (2012)].

Cheng, Xuan; Sullaphen, Jivika; Valanoor, Nagarajan [School of Materials Science and Engineering, University of New South Wales, Sydney NSW 2052 (Australia); Weyland, Matthew [Department of Materials Engineering and Monash Centre for Electron Microscopy, Monash University, Melbourne VIC 3800 (Australia); Liu, Hongwei [Australian Centre for Microscopy and Microanalysis, University of Sydney, Sydney NSW 2006 (Australia)

2014-03-01T23:59:59.000Z

166

Combined molten salt–Ni/Al2O3 as synergistic medium for high-quality syngas production  

Science Journals Connector (OSTI)

Abstract Proposed synergistic use of a combined medium of molten salt and Ni/Al2O3 (MS-Ni) was investigated for its enhancement of cellulose pyrolysis for high-quality syngas production. Clean renewable solar energy is to be stored at a high temperature in molten salt (MS) and provides the heat of pyrolysis. The MS-Ni medium could increase H2 yield by 3-folds while CO yield slightly increased by 15%, compared to the case of only MS medium. The peak rate of H2 production nearly quadrupled while the peak rate of CO production increased 2.5 times at about 150 and 80 K lower temperatures, respectively. The ratio of selectivity of syngas to undesired CH4 was nearly doubled. Arrhenius rate expressions for pseudo-first-order pyrolytic reaction are derived from the experimental data to give activation energies of 206 and 128 kJ mol?1 for the MS and the MS-Ni mediums, respectively. The experimental results clearly validated the role of MS-Ni as a synergistic medium for high-quality syngas production from cellulosic biomass pyrolysis.

Sakhon Ratchahat; Satoshi Kodama; Wiwut Tanthapanichakoon; Hidetoshi Sekiguchi

2014-01-01T23:59:59.000Z

167

Statistical simulation of small fatigue crack nucleation and coalescence in a lamellar TiAl alloy  

SciTech Connect

This article examines the possibility of fatigue failure as the result of fatigue crack nucleation and coalescence at stress ranges below the fatigue limit and the large crack threshold where fatigue cracks are expected not to grow. By representing the material as a two-dimensional array of beam elements, the nucleation of nonpropagating small cracks at various material locations is modeled via a statistical approach that considers fatigue crack nucleation by accumulation of damage at randomly distributed weak regions. Once nucleated, the fatigue cracks do not propagate but extend only by linking with fatigue cracks subsequently formed in the contiguous elements. Result of the computer simulation suggests that fatigue failure by crack nucleation and coalescence is feasible, but the cycles-to-coalescence is much longer than the cycles-to-initiation for the first crack. Implications of the results in fatigue life assessment based on the Kitagawa diagram are discussed for TiAl alloys.

Chan, K.S. [Southwest Research Inst., San Antonio, TX (United States); Wittowsky, B. [Proctor and Gamble European Service GmbH, Euskirchen (Germany); Pfuff, M. [GKSS Research Center, Geesthacht (Germany)

1999-05-01T23:59:59.000Z

168

Elastic properties of low density core (LDC) Ti-6Al-4V sandwich cores  

SciTech Connect

Lightweight, structurally efficient low density core (LDC) sandwich structures can be produced by entrapping argon gas within a finely dispersed distribution of pores in a microstructure and using a high temperature anneal to cause pore growth by gas expansion. This results in a porous microstructure with a relative density as low as {approximately}0.70. Laser ultrasonic methods have been used to measure the longitudinal and shear wave velocities and hence the elastic properties of LDC Ti-6Al-4V cores prior to, and after gas expansion treatments of up to 48 hr at 920 C. The data were compared with several analytical models for predicting the volume fraction of porosity dependent elastic properties of porous materials.

Queheillalt, D.T.; Wadley, H.N.G. [Univ. of Virginia, Charlottesville, VA (United States). IPM Lab.; Schwartz, D.S. [Boeing Co., St. Louis, MO (United States)

1998-12-31T23:59:59.000Z

169

Hydrogen production by steam reforming of LNG over Ni/Al2O3-ZrO2 catalysts: Effect of ZrO2 and preparation method of Al2O3-ZrO2  

Science Journals Connector (OSTI)

An Al2O3-ZrO2 support was prepared by grafting a zirconium precursor onto the surface of commercial ?-Al2O3. A physical mixture of Al2O3-ZrO2 was also prepared for the purpose of comparison. Ni/Al2O3-ZrO2 catalys...

Jeong Gil Seo; Min Hye Youn; Sunyoung Park…

2008-01-01T23:59:59.000Z

170

Upper critical field of Ti and ?-TiAl alloys: Evidence of an intrinsic type-II superconductivity in pure Ti  

Science Journals Connector (OSTI)

The upper critical field Hc2 of ?-Ti1-xAlx(0Fermi velocity obtained here is substantially lower than predicted by band calculation. The present work gives clear evidence that pure Ti is an intrinsic type-II superconducting element due to its very low renormalized Fermi velocity.

Liu Shumei; Zhang Dianlin; Jing Xiunian; Lu Li; Li Shanlin; Kang Ning; Wu Xiaosong; J. J. Lin

2000-10-01T23:59:59.000Z

171

Long period structures in Ti1+xAl3-x alloys : experimental evidence of a devil's staircase ?  

E-Print Network (OSTI)

595 Long period structures in Ti1+xAl3-x alloys : experimental evidence of a devil's staircase ? A of a so-called devil's staircase. The experimental results are compared with those obtained in Ag3Mg domain size M depends on temperature; this dependence corresponds to a simple (harmless) staircase below

Boyer, Edmond

172

Electronic and atomic structures of Ti{sub 1-x}Al{sub x}N thin films related to their damage behavior  

SciTech Connect

Ti and Al K-edge x-ray absorption spectroscopy is used to investigate the electronic structure of Ti{sub 1-x}Al{sub x}N thin films deposited by reactive magnetron sputtering. The experimental near edge spectra of TiN and AlN are interpreted in the light of unoccupied density of state band structure calculations. The comparison of the structural parameters derived from x-ray absorption fine structure and x-ray diffraction reveals segregation between Al-rich and Ti-rich domains within the Ti{sub 1-x}Al{sub x}N films. Whereas x-ray diffraction probes only the crystallized domains, the structural information derived from extended x-ray absorption fine structure analysis turns on both crystalline and grain boundaries. The results are discussed by considering the damage behavior of the films depending on the composition.

Tuilier, M.-H.; Pac, M.-J.; Girleanu, M.; Covarel, G.; Arnold, G.; Louis, P. [Laboratoire de Mecanique, Materiaux et Procedes de Fabrication, Universite de Haute Alsace, 61 rue Albert Camus, F-68093 Mulhouse cedex (France); Rousselot, C. [Institut FEMTO-ST (UMR CNRS 6174), Universite de Franche-Comte, BP 71427, F-25211 Montbeliard cedex (France); Flank, A.-M. [CNRS--UR1 SOLEIL, F-91192 Gif sur Yvette cedex (France)

2008-04-15T23:59:59.000Z

173

Microstructural aspects of low-pressure plasma-sprayed CoNiCrAlY coating on Hastelloy X  

SciTech Connect

A Co-32Ni-21Cr-8Al-0.5Y alloy coating plasma sprayed on Hastelloy X. The microstructure of the coating layer consist of ..gamma.. phase solid solution, ..gamma..' phase, and Y-rich intermetallic phase. This coating exhibits excellent oxidation and sulfidation resistance after exposure in air and in sodium sulfate at 1,000/sup 0/C for 60 h, due to the formation of ..cap alpha..-Al/sub 2/O/sub 3/ oxide scale. However, the presence of chloride in the sodium sulfate leads to rupture of the aluminium oxide scale, and this results in the precipitation of chlorides and sulfides within the coating layer.

Tjong, S.C.; Shih, G.E.; Ho, N.J.

1989-01-01T23:59:59.000Z

174

CeO2 Promoted Ni/Al2O3 Catalyst in Combined Steam and Carbon Dioxide Reforming of Methane for Gas to Liquid (GTL) Process  

Science Journals Connector (OSTI)

The effect of ceria promotion over Ni/Al2O3...catalysts on the catalytic activity and coke formation was investigated in combined steam and carbon dioxide reforming of methane (CSCRM) to produce synthesis gas (H2

Kee Young Koo; Hyun-Seog Roh; Un Ho Jung; Wang Lai Yoon

2009-06-01T23:59:59.000Z

175

Ab-initio First Principle Modeling of Structural and Magnetic Phase Transformations in Co-Ni-Al Based Shape Memory Alloys  

E-Print Network (OSTI)

. These magnetic properties are mainly attributed to the martensitic structural phase trans- formation these material experience in response to temperature variation. Co-Ni-Al based alloys are one of the most promising ferromagnetic shape memory alloy FSMA that has...

Thawabi, Hassan S

2013-04-16T23:59:59.000Z

176

PII S0016-7037(98)00136-7 The kinetics of mixed Ni-Al hydroxide formation on clay and aluminum oxide minerals  

E-Print Network (OSTI)

PII S0016-7037(98)00136-7 The kinetics of mixed Ni-Al hydroxide formation on clay and aluminum. This finding indicates that the dissolution of clay and aluminum oxide minerals can be promoted by metal ions

Sparks, Donald L.

177

Reforming of Isooctane over Ni?Al2O3 Catalysts for Hydrogen Production:? Effects of Catalyst Preparation Method and Nickel Loading  

Science Journals Connector (OSTI)

Reforming of Isooctane over Ni?Al2O3 Catalysts for Hydrogen Production:? Effects of Catalyst Preparation Method and Nickel Loading ... Typically, hydrogen can be produced from hydrocarbons or oxygenated hydrocarbons. ... However, the effects of the catalyst preparation method and nickel loading on the performance of Ni?Al2O3 catalysts for the partial oxidation of gasoline to produce hydrogen have not been reported before in the literature. ...

Hussam H. Ibrahim; Prashant Kumar; Raphael O. Idem

2007-02-20T23:59:59.000Z

178

One-Step Conversion of Biomass-Derived 5-Hydroxymethylfurfural to 1,2,6-Hexanetriol Over Ni–Co–Al Mixed Oxide Catalysts Under Mild Conditions  

Science Journals Connector (OSTI)

One-Step Conversion of Biomass-Derived 5-Hydroxymethylfurfural to 1,2,6-Hexanetriol Over Ni–Co–Al Mixed Oxide Catalysts Under Mild Conditions ... A sustainable process with a one-step conversion of biomass-derived 5-hydroxymethylfurfural (HMF) to 1,2,6-hexanetriol is presented. ... The conversion of biomass-derived 5-hydroxymethylfurfural (HMF) was examined over Ni–Co–Al mixed oxide catalysts derived from corresponding hydrotalcite-like compounds (HTlcs). ...

Shengxi Yao; Xicheng Wang; Yijun Jiang; Feng Wu; Xinguo Chen; Xindong Mu

2013-10-01T23:59:59.000Z

179

Ni catalysts derived from Mg–Al layered double hydroxides for hydrogen production from landfill gas conversion  

Science Journals Connector (OSTI)

A layered double hydroxide (LDH) precursor with a hydrotalcite-like structure containing Ni/Mg/Al cations was prepared. A series of Ni catalysts containing mixed-oxides and spinel phases were then obtained through thermal treatment of the LDH precursor. X-ray diffraction (XRD), transmission electron microscopy (TEM), and temperature-programmed reduction (TPR) revealed that the LDH derived Ni catalysts have well-dispersed nickel phases upon reduction. The thermal treatment temperatures have noticeable effects on the specific surface area, pore volume, phase transformation, particle size, and reducibility of the catalysts. Thermal treatment temperatures up to 700 °C promote the generation of mesopores which facilitate an increase in specific area and pore volume. Beyond 700 °C sintering occurs, mesopores collapse, and specific area and pore volume decrease. High thermal treatment temperatures favor the phase transformation to spinel solid solutions and the particle size growth. Metal-support interaction is enhanced but reducibility is hindered due to the formation of spinel solid solution phases. The LDH derived Ni catalysts were tested for landfill gas conversion at 750 °C and have shown excellent activity and stability in terms of methane conversion. At gas hourly space velocity (GHSV) of 240,000 h?1 and pressure of 1 atm, 81% methane conversion was achieved during a 48 h test period without apparent catalyst deactivation.

Qingsong Wang; Wei Ren; Xueliang Yuan; Ruimin Mu; Zhanlong Song; Xiaolin Wang

2012-01-01T23:59:59.000Z

180

Sulfur behavior in chemical looping combustion with NiO/Al{sub 2}O{sub 3} oxygen carrier  

SciTech Connect

Chemical looping combustion (CLC) is a novel technology where CO{sub 2} is inherently separated during combustion. Due to the existence of sulfur contaminants in the fossil fuels, the gaseous products of sulfur species and the interaction of sulfur contaminants with oxygen carrier are a big concern in the CLC practice. The reactivity of NiO/Al{sub 2}O{sub 3} oxygen carrier reduction with a gas mixture of CO/H{sub 2} and H{sub 2}S is investigated by means of a thermogravimetric analyzer (TGA) and Fourier Transform Infrared spectrum analyzer in this study. An X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and scanning electron microscope (SEM) are used to evaluate the phase characterization of reacted oxygen carrier, and the formation mechanisms of the gaseous products of sulfur species are elucidated in the process of chemical looping combustion with a gaseous fuel containing hydrogen sulfide. The results show that the rate of NiO reduction with H{sub 2}S is higher than the one with CO. There are only Ni and Ni{sub 3}S{sub 2} phases of nickel species in the fully reduced oxygen carrier, and no evidence for the existence of NiS or NiS{sub 2}. The formation of Ni{sub 3}S{sub 2} is completely reversible during the process of oxygen carrier redox. A liquid phase sintering on the external surface of reduced oxygen carriers is mainly attributed to the production of the low melting of Ni{sub 3}S{sub 2} in the nickel-based oxygen carrier reduction with a gaseous fuel containing H{sub 2}S. Due to the sintering of metallic nickel grains on the external surface of the reduced oxygen carrier, further reaction of the oxygen carrier with H{sub 2}S is constrained, and there is no increase of the sulfidation index of the reduced oxygen carrier with the cyclical reduction number. Also, a continuous operation with a syngas of carbon monoxide and hydrogen containing H{sub 2}S is carried out in a 1 kW{sub th} CLC prototype based on the nickel-based oxygen carrier, and the effect of the fuel reactor temperature on the release of gaseous products of sulfur species is investigated. (author)

Shen, Laihong; Gao, Zhengping; Wu, Jiahua; Xiao, Jun [Thermoenergy Engineering Research Institute, Southeast University, Nanjing 210096 (China)

2010-05-15T23:59:59.000Z

Note: This page contains sample records for the topic "ni ti al" 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

Methane Steam Reforming Kinetics on a Ni/Mg/K/Al2O3 Catalyst  

Science Journals Connector (OSTI)

The kinetics of methane steam reforming were studied on a Ni/Mg/K/...2O3...catalyst that was developed for conditioning of biomass-derived syngas. Reactions were conducted in a packed-bed reactor while the concen...

Allison M. Robinson; Megan E. Gin; Matthew M. Yung

2013-12-01T23:59:59.000Z

182

Structure Analysis of a Precipitate Phase in an Ni-Rich High...  

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

Analysis of a Precipitate Phase in an Ni-Rich High Temperature NiTiHf Shape Memory Alloy. Structure Analysis of a Precipitate Phase in an Ni-Rich High Temperature NiTiHf Shape...

183

Ultrathin highly uniform Ni(Al) germanosilicide layer with modulated B8 type Ni{sub 5}(SiGe){sub 3} phase formed on strained Si{sub 1?x}Ge{sub x} layers  

SciTech Connect

We present a method to form ultrathin highly uniform Ni(Al) germanosilicide layers on compressively strained Si{sub 1?x}Ge{sub x} substrates and their structural characteristics. The uniform Ni(Al) germanosilicide film is formed with Ni/Al alloy at an optimized temperature of 400?°C with an optimized Al atomic content of 20?at.?%. We find only two kinds of grains in the layer. Both grains show orthogonal relationship with modified B8 type phase. The growth plane is identified to be (10-10)-type plane. After germanosilicidation the strain in the rest Si{sub 1?x}Ge{sub x} layer is conserved, which provides a great advantage for device application.

Liu, Linjie; Xu, Dawei [Peter Grünberg Institute 9, Forschungzentrum Jülich, 52425 Jülich (Germany) [Peter Grünberg Institute 9, Forschungzentrum Jülich, 52425 Jülich (Germany); State Key Laboratory of Functional Material for Informatics, Shanghai Institute of Microsystem and Information Technology, CAS, Shanghai 200050 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Jin, Lei [Peter Grünberg Institute 5, Forschungszentrum Jülich, 52425 Jülich (Germany)] [Peter Grünberg Institute 5, Forschungszentrum Jülich, 52425 Jülich (Germany); Knoll, Lars; Wirths, Stephan; Nichau, Alexander; Buca, Dan; Mussler, Gregor; Holländer, Bernhard; Zhao, Qing-Tai, E-mail: q.zhao@fz-juelich.de; Mantl, Siegfried [Peter Grünberg Institute 9, Forschungzentrum Jülich, 52425 Jülich (Germany)] [Peter Grünberg Institute 9, Forschungzentrum Jülich, 52425 Jülich (Germany); Feng Di, Zeng; Zhang, Miao [State Key Laboratory of Functional Material for Informatics, Shanghai Institute of Microsystem and Information Technology, CAS, Shanghai 200050 (China)] [State Key Laboratory of Functional Material for Informatics, Shanghai Institute of Microsystem and Information Technology, CAS, Shanghai 200050 (China)

2013-12-02T23:59:59.000Z

184

Demonstration of High Efficiency Elastocaloric Cooling with Large Delta- T Using NiTi Wires  

SciTech Connect

Vapor compression (VC) is by far the most dominant technology for meeting all cooling and refrigeration needs around the world. It is a mature technology with the efficiency of modern compressors approaching the theoretical limit, but its envi-ronmental footprint remains a global problem. VC refrigerants such as hydrochlo-roflurocarbons (HCFCs) and hydrofluorocarbons (HFCs) are a significant source of green house gas (GHG) emissions, and their global warming potential (GWP) is as high as 1000 times that of CO2. It is expected that building space cooling and re-frigeration alone will amount to {approx} 5% of primary energy consumption and {approx}5% of all CO2 emission in U.S. in 2030 . As such, there is an urgent need to develop an al-ternative high-efficiency cooling technology that is affordable and environmentally friendly. Among the proposed candidates, magnetocaloric cooling (MC) is currently received a lot of attention because of its high efficiency. However, MC is inherently expensive because of the requirement of large magnetic field and rare earth materi-als. Here, we demonstrate an entirely new type of solid-state cooling mechanism based on the latent heat of reversible martensitic transformation. We call it elasto-caloric cooling (EC) after the superelastic transformation of austenite it utilizes. The solid-state refrigerant of EC is cost-effective, and it completely eliminates the use of any refrigerants including HCFCs/HFCs. We show that the COP (coefficient of per-formance) of a jugular EC with optimized materials can be as high as > 10 with measured {Delta}T of 17 C.

Cui, Jun; Wu, Yiming; Muehlbauer, Jan; Hwang, Yunho; Radermacher, Reinhard; Fackler, Sean; Wuttig, Manfred; Takeuchi, Ichiro

2012-08-01T23:59:59.000Z

185

Mechanisms Associated with Rumpling of Pt-Modified Beta-NiAl Coatings  

SciTech Connect

The formation of surface undulations (i.e. rumpling) at the bond coat/thermally grown oxide (TGO) interface has been shown to cause failure by spallation of the ceramic top coat in aero-turbine systems. Many mechanisms have been proposed concerning the cause of these surface distortions; however, there is little agreement on what may be the dominating cause of the rumpling behavior. Of there mechanisms, the reversible phase transformation from a cubic {beta}-NiAl structure to a face centered tetragonal (FCT) martensitic phase was of particular interest because of its ability to form surface rumpling in Pt-modified {beta} bulk alloys. However, the bulk alloys used in obtaining that result were simple ternary systems and not relevant to actual coating compositions as other alloying elements enter the coating due to coating/substrate interdiffusion at high temperature. In the current study, the depletion behavior of a commercial coating was studied. Compositions from the depletion path were determined and bulk alloys representing these coating compositions were prepared. The martensitic phase transformation was then characterized using DSC and XRD. The martensitic start temperature on cooling, Ms, was consistently found to be significantly lower than previously reported values (e.g. 530 C vs 100 C). Because of the low Ms temperature, the formation of the martensitic phase was concluded to be unnecessary for the occurrence of rumpling. However, cyclic exposure treatments at low temperature ({approx} 400 C) of bulk alloys and commercial coatings did show the detrimental effects of the phase transformation in the form of crack formation and propagation leading to eventual failure of the alloys. The current work also infers that the differences in coefficient of thermal expansion (CTE) mismatch between the coating and substrate are the dominating factor leading to rumpling. Dilatometry measurements were made on bulk alloys representing depleted coatings and the superalloy substrate to determine CTE as a function of temperature. Finally, simulations were completed to help determine the role of CTE mismatch. It was found that these results compared closely to those collected during experimental cyclic exposure treatments; although, modification to the current model were found to be needed in order to truly simulate rumpling.

Joseph Peter Henderkott

2007-12-01T23:59:59.000Z

186

X-ray diffraction line profile analysis of deformation microstructure in boron modified Ti-6Al-4V alloy  

SciTech Connect

X-ray diffraction line profile analysis (XRDLPA) techniques have been applied to investigate the deformed microstructure of a recently developed boron modified two-phase titanium alloy Ti-6Al-4V. The alloy was hot compressed at 750 deg. C up to 50% height reduction at two different strain rates (10{sup -3} S{sup -1} and 1 S{sup -1}). Microstructural parameters like average domain size, average microstrain within the domain and dislocation density of the two phases were determined using X-ray diffraction line profile analysis. The results indicate an increase in the microstrain and dislocation density for the {alpha}-phase and decrease for the {beta}-phase in the case of boron modified alloys as compared to the normal material. Microstructural modifications viz. the grain refinement and the presence of hard, brittle TiB particles in the case of boron modified alloy are held responsible for the observed difference in the dislocation density. - Research Highlights: {yields} Microstructural examination of hot compressed Ti64 with and without boron addition by XRDLPA. {yields} Smaller average domain size in alpha-phase compared to the corresponding alpha-phase in all cases. {yields} Higher microstrain and dislocation density for {alpha} phase and lower for {beta} phase in case of Ti64+B. {yields} Decrease in domain size while increase in micro-strain and dislocation density with strain rate. {yields} Strain accumulation around TiB particles responsible for high dislocation density in {alpha} phase.

Sarkar, Apu; Roy, Shibayan; Suwas, Satyam, E-mail: satyamsuwas@materials.iisc.ernet.in

2011-01-15T23:59:59.000Z

187

Enhanced thermal stability and microhardness in Zr{endash}Ti{endash}Cu{endash}Ni{endash}Be bulk amorphous alloy by carbon addition  

SciTech Connect

The effects of carbon addition on thermal stability and hardness of Zr{sub 41}Ti{sub 14}Cu{sub 12.5}Ni{sub 10}Be{sub 22.5} bulk amorphous alloy were investigated. It is found that a small amount of carbon addition further extends the supercooled liquid range and enhances the thermal stability and strength of the alloy. More carbon addition results in the formation of a crystalline and amorphous mixture accompanied by a pronounced increase in microhardness. The effects of the carbon addition on the amorphous alloy are discussed from the structural point of view. {copyright} {ital 1997 American Institute of Physics.}

Wang, W.; Wei, Q. [Hahn-Meitner-Institut Berlin, D-14109 Berlin (Germany)] [Hahn-Meitner-Institut Berlin, D-14109 Berlin (Germany); Bai, H.Y. [Institut fuer Werkstofforschung, GKSS-Forschungszentrum Geesthacht, D-21502 Geesthacht (Germany)] [Institut fuer Werkstofforschung, GKSS-Forschungszentrum Geesthacht, D-21502 Geesthacht (Germany)

1997-07-01T23:59:59.000Z

188

Silicide precipitation in a {gamma}-based Ti-47Al-2W-0.5Si alloy  

SciTech Connect

Although some work on microstructure of silicides in {gamma}-TiAl alloys has been done, it is restricted to the alloys containing high content of silicon ({approximately}3at.%). Furthermore, to the authors` knowledge, the crystal orientation relation between silicide and {beta} matrix that is stabilized to room temperature in the alloys containing transition elements (such as Nb, V, W, Cr), has not been reported yet. The present investigation was undertaken /to study the silicides in a {gamma}-TiAl base alloy with 2 at.% W addition containing 0.28--0.59 at.% Si after different heat treatments, to understand the effects of silicon content and heat treatment on the formation and morphology of silicides.

Yin, W.M. [CNR-ITM, Cinisello Balsamo (Italy)] [CNR-ITM, Cinisello Balsamo (Italy); [Chinese Academy of Sciences, Shenyang (China). Inst. of Metal Research; Lupinc, V. [CNR-ITM, Cinisello Balsamo (Italy)] [CNR-ITM, Cinisello Balsamo (Italy)

1997-07-15T23:59:59.000Z

189

In-situ sensing of the expansion of low density core (LDC) Ti-6Al-4V sandwich structures  

SciTech Connect

A combination multifrequency eddy current and laser ultrasonic sensors have been used to measure the pore expansion kinetics and elastic moduli evolution during the annealing of low density core (LDC) Ti-6Al-4V sandwich structures. The LDC samples were heated to 920 C and held there for up to 12 hr. The eddy current sensor measured the sample thickness (i.e., relative density) and revealed that the samples began to expand early during heating and was nearly complete after 4 hr at 920 C. The laser ultrasonic sensor measurements indicated a concomitant decrease in the elastic moduli with the reduction in relative density. The combination of an eddy current and laser ultrasonic sensor is therefore able to measure both the density and the elastic moduli independently during the annealing stage of LDC Ti-6Al-4V sandwich structure processing providing a simple method for directly controlling the parameters most critical to aerospace applications of these new materials.

Queheillalt, D.T.; Choi, B.W.; Wadley, H.N.G. [Univ of Virginia, Charlottesville, VA (United States). IPM Lab.; Schwartz, D.S. [Boeing Co., St. Louis, MO (United States)

1998-12-31T23:59:59.000Z

190

Temperature effect on the microstructural development of Al–Ni layered binary couples produced by an unconventional method  

Science Journals Connector (OSTI)

Abstract In this work, the authors have used an unconventional experimental route that consists of (i) deposition of a nickel coating onto an aluminium substrate and (ii) the subsequent heat treatment of created couple in order to produce intermetallic-layered structures, hypereutectic or bulk aluminide intermetallic alloys. The procedure was conducted by controlling chemical concentrations in the Al-rich corner of Al–Ni binary system. The couple was prepared by high velocity oxyfuel spraying of 99.0 wt.% Ni powder onto the surface of 99.999 wt.% Al sheet. The specimens for heat treatment were manufactured immediately after the spraying. The heat treatment was carried out in a differential thermal analysis apparatus by using the temperature range of 600–1200 °C, thus considering the solid state, transient liquid as well as liquid phase of aluminium, with a constant heating/cooling rate of 5 °C/min in an argon atmosphere. Microstructural development of produced alloys was studied by conventional metallography and scanning electron microscopy. Formed intermetallic layers and compounds were evaluated by using energy dispersive microanalysis and image analysis techniques. The development of a novel ultra-fine eutectic alloy is reported.

L. ?elko; S. Díaz de la Torre; L. Klakurková; J. Kaiser; B. Smetana; K. Sláme?ka; M. Žaludová; J. Švejcar

2014-01-01T23:59:59.000Z

191

Fabricating superconducting interfaces between artificially grown LaAlO{sub 3} and SrTiO{sub 3} thin films  

SciTech Connect

Realization of a fully metallic two-dimensional electron gas (2DEG) at the interface between artificially grown LaAlO{sub 3} and SrTiO{sub 3} thin films has been an exciting challenge. Here we present for the first time the successful realization of a superconducting 2DEG at interfaces between artificially grown LaAlO{sub 3} and SrTiO{sub 3} thin films. Our results highlight the importance of two factors—the growth temperature and the SrTiO{sub 3} termination. We use local friction force microscopy and transport measurements to determine that in normal growth conditions the absence of a robust metallic state at low temperature in the artificially grown LaAlO{sub 3}/SrTiO{sub 3} interface is due to the nanoscale SrO segregation occurring on the SrTiO{sub 3} film surface during the growth and the associated defects in the SrTiO{sub 3} film. By adopting an extremely high SrTiO{sub 3} growth temperature, we demonstrate a way to realize metallic, down to the lowest temperature, and superconducting 2DEG at interfaces between LaAlO{sub 3} layers and artificially grown SrTiO{sub 3} thin films. This study paves the way to the realization of functional LaAlO{sub 3}/SrTiO{sub 3} superlattices and/or artificial LaAlO{sub 3}/SrTiO{sub 3} interfaces on other substrates.

Li, Danfeng, E-mail: Danfeng.Li@unige.ch; Gariglio, Stefano; Cancellieri, Claudia; Fête, Alexandre; Stornaiuolo, Daniela; Triscone, Jean-Marc [DPMC, University of Geneva, 24 Quai Ernest Ansermet, 1211 Geneva (Switzerland)

2014-01-01T23:59:59.000Z

192

Influence of Microstructure on High-Cycle Fatigue of Ti-6Al-4V: Bimodal vs. Lamellar Structures  

E-Print Network (OSTI)

for such failures in Ti-6Al-4V, a commonly used turbine blade alloy, specifically for fan and compressor blades.K. NALLA, B.L. BOYCE, J.P. CAMPBELL, J.O. PETERS, and R.O. RITCHIE The high-cycle fatigue (HCF) of titanium] HCF can result in essentially unpredictable used for blade and disk applications in the front (low

Ritchie, Robert

193

Statistical evaluation of potential damage to the Al(OH)3 layer on nTiO2 particles in the presence of swimming pool and seawater  

Science Journals Connector (OSTI)

Nanosized TiO2 particles (nTiO2) are usually coated with an Al(OH)3 layer when used in sunscreen to shield against the harmful effects of free radicals that are generated when these particles are exposed to UV r...

Jurate Virkutyte; Souhail R. Al-Abed

2012-03-01T23:59:59.000Z

194

Investment casting of {gamma}-TiAl-based alloys: Microstructure and data base for gas turbine applications  

SciTech Connect

Investment casting is regarded as an economic processing technology for the production of {gamma}-TiAl based components for gas turbine applications. Near net-shape parts can be cast such that they are free from pores and flaws after adequate `HIP`ping. The inhomogeneous cast microstructure which results from locally varying cooling rates (e.g. in the root and foil of a blade), however, is often retained even after heat-treatments necessary to achieve a balance of properties for a given application. Appropriate modifications of the alloy chemistry may lead to an improved microstructural homogeneity in the cast parts. Data bases of properties (tensile properties, creep, fatigue and rupture strength, fracture and impact toughness, oxidation and corrosion resistance) which are relevant for potential gas turbine applications have been assessed for different cast {gamma}-TiAl alloys with different microstructures. These are compared with corresponding properties of nickel-based and iron-based superalloys {gamma}-TiAl is competing with for substitution.

Wagner, R.; Appel, F.; Dogan, B. [GKSS Research Center, Geesthacht (Germany). Inst. for Materials Research] [and others

1995-12-31T23:59:59.000Z

195

Characterization of Ti diffusion in PVD deposited WTi/AlCu metallization on monocrystalline Si by means of secondary ion mass spectroscopy  

Science Journals Connector (OSTI)

The diffusion behavior of Titanium in Al0.5Cu/W18Ti (at.%) metallization stacks on monocrystalline Silicon has been investigated. The metallization system was prepared by in situ sputtering deposition. It is demonstrated that \\{WTi\\} is not stable as a diffusion barrier between Al0.5Cu and Si in temperature ranges between 623 K and 673 K due to Ti depletion. The Ti diffusion in Al0.5Cu is characterized by diffusion profiles prepared by secondary ion mass spectroscopy after annealing. The activation energy derived from this data is 2.28 eV for Ti diffusion into Al0.5Cu. The causal chain of detecting this behavior is described application-oriented.

M. Plappert; O. Humbel; A. Koprowski; M. Nowottnick

2012-01-01T23:59:59.000Z

196

Tic-Ni-based composite materials dispersion-strengthened by nanoparticles for electrospark deposition  

Science Journals Connector (OSTI)

The macrokinetic characteristic properties of the combustion process of mixtures in the TiC-Ni system with additives of nanosized ZrO2, Al2O3, Mo-Al2O3 powders, as well as the phase composition, structure, and pr...

E. A. Levashov; Yu. S. Pogozhev; A. E. Kudryashov…

2008-10-01T23:59:59.000Z

197

A study of the deactivation of low loading Ni/Al2O3 steam reforming catalyst by tetrahydrothiophene  

Science Journals Connector (OSTI)

Abstract The steam reforming (SR) of ethanol/phenol mixture (168 gTOT/N m3, ethanol:phenol 2:1 mol, GHSV = 54,000 h? 1), assumed as a model for tar mixtures, has been studied over a 5% Ni/Al2O3 catalyst (155 m2/g), in the presence and in the absence of 210 ppm tetrahydrothiophene (THT) as a sulphur containing contaminant. The sulphidation of the catalyst by THT has been studied by IR spectroscopy. Infrared spectra of CO adsorbed at low temperature over the oxidized, the reduced and the sulphurized catalyst have also been recorded. The catalyst acts as a bifunctional one, with the behaviour attributed to the uncovered support (alumina modified by nickel ions) at 773 K (dehydration of ethanol to ethylene, dehydrogenation to acetaldehyde and alkylation of phenol with ethanol) that fully disappears at 973 K when steam reforming occurs very selectively. By lowering back the reaction temperature, the support behaviour reappears. THT poisons selectively the Ni component, thus causing the appearance of the support behaviour also at 973 K. IR experiments show that THT deposes sulphur at the catalyst surface with the production of gas-phase 1,3-butadiene, thus converting the catalyst into a “sulphided” SR-inactive state. The steam reforming activity of the poisoned catalyst progressively reappears upon feeding back S-free feed at 973 K. IR study suggests that steam “cleans” the catalyst surface by sulphur, generating a “disordered” surface with dispersed Ni2 + and Ni0 species, that could slowly re-approach the initial active state.

Gabriella Garbarino; Alvaro Romero Perez; Elisabetta Finocchio; Guido Busca

2013-01-01T23:59:59.000Z

198

Inuence of foreign-object damage on crack initiation and early crack growth during high-cycle fatigue of Ti6Al4V  

E-Print Network (OSTI)

; Ti±6Al±4V 1. Introduction The high-cycle fatigue (HCF) of aircraft gas-turbine engine components has of small surface fatigue cracks in a Ti±6Al±4V alloy, processed for typical turbine blade applications microcracks in the damaged zone (seen only at the higher impact velocities). Furthermore, the eect of residual

Ritchie, Robert

199

Catalytic Effect of Ti for Hydrogen Cycling in NaAlH4  

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

+ 2AlH 3 3 NaAlH 4 M. Mamula et al., Coll. Czechoslov. Chem. Commun. 32, 884 (1967). Atomic Hydrogen Interacting with Al Surfaces "H adsorption and the formation of alane...

200

On the preparation of TiAl alloy by direct reduction of the oxide mixtures in calcium chloride melt  

SciTech Connect

In recent years, TiAl-based intermetallic alloys are being increasingly considered for application in areas such as (i) automobile/transport sector (passenger cars, trucks and ships) (ii) aerospace industry (jet engines and High Speed Civil Transport propulsion system) and (iii) industrial gas turbines. These materials offer excellent (i) high temperature properties (at higher than 6000C) (ii) mechanical strength and (iii) resistance to corrosion and as a result have raised renewed interest. The combination of these properties make them possible replacement materials for traditional nickel-based super-alloys, which are nearly as twice as dense (than TiAl based alloys). Since the microstructures of these intermetallic alloys affect, to a significant extent, their ultimate performance, further improvements (by way of alteration/modification of these microstructures), have been the subject matter of intense research investigations. It has now been established that the presence of alloy additives, such as niobium, tantalum, manganese, boron, chromium, silicon, nickel and yttrium etc, in specific quantities, impart marked improvement to the properties, viz. fatigue strength, fracture toughness, oxidation resistance and room temperature ductility, of these alloys. From a number of possible alloy compositions, {gamma}-TiAl and Ti-Al-Nb-Cr have, of late, emerged as two promising engineering alloys/materials. . The conventional fabrication process of these alloys include steps such as melting, forging and heat treatment/annealing of the alloy compositions. However, an electrochemical process offers an attractive proposition to prepare these alloys, directly from the mixture of the respective oxides, in just one step. The experimental approach, in this new process, was, therefore, to try to electrochemically reduce the (mixed) oxide pellet to an alloy phase. The removal of oxygen, from the (mixed) oxide pellet, was effected by polarizing the oxide pellet against a graphite electrode in a pool of molten calcium chloride at a temperature of 9000C. The dominant mechanism of the oxygen removal was the ionization of oxygen followed by its subsequent discharge, as CO2/CO, at the anode surface. The removal of oxygen from the oxide mixture helped form the alloy in situ. The presentation shall cover the detailed experimental results pertaining to the preparation, evaluation and characterization of Ti-47Al-2Nb-2Cr (atom%) alloy.

Prabhat K. Tripathy; Derek J. Fray

2011-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "ni ti al" from the National Library of EnergyBeta (NLEBeta).
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201

Mg{sub 8}Rh{sub 4}B - A new type of boron stabilized Ti{sub 2}Ni structure  

SciTech Connect

The new magnesium rhodium boron compound Mg{sub 8}Rh{sub 4}B has been synthesized by reaction of the metal powders with crystalline or amorphous boron or the RhB precursor. The crystal structure of Mg{sub 8}Rh{sub 4}B was solved using single-crystal X-ray diffraction data (space group Fd3-bar m, a=12.1711(4)A, Z=8, 174 reflections, R{sub F}=0.016). The crystal structure can be described as a filled Ti{sub 2}Ni type where the interstitial sites 8b (12,12,12), located at the center of two nested Mg{sub 4}Rh{sub 4} tetrahedra, are occupied by boron atoms. Taking into account the absence of the Ti{sub 2}Ni-type phase in the binary Mg-Rh system, the boron atoms can be considered as stabilizing this structural motif. From the bonding analysis with the electron localization function the crystal structure is described as covalently bonded [Rh{sub 4}B]{sup 3-} anions, embedded in a cationic magnesium matrix.

Alekseeva, A.M. [Max-Planck-Institut fuer Chemische Physik fester Stoffe, Noethnitzer Strasse 40, 01187 Dresden (Germany) and Department of Chemistry, Moscow State University, Moscow 119992 (Russian Federation)]. E-mail: alekseev@cpfs.mpg.de; Abakumov, A.M. [Max-Planck-Institut fuer Chemische Physik fester Stoffe, Noethnitzer Strasse 40, 01187 Dresden (Germany); Department of Chemistry, Moscow State University, Moscow 119992 (Russian Federation); EMAT, University of Antwerp, Antwerp B-2020 (Belgium); Leithe-Jasper, A. [Max-Planck-Institut fuer Chemische Physik fester Stoffe, Noethnitzer Strasse 40, 01187 Dresden (Germany); Schnelle, W. [Max-Planck-Institut fuer Chemische Physik fester Stoffe, Noethnitzer Strasse 40, 01187 Dresden (Germany); Prots, Yu. [Max-Planck-Institut fuer Chemische Physik fester Stoffe, Noethnitzer Strasse 40, 01187 Dresden (Germany); Chizhov, P.S. [Max-Planck-Institut fuer Chemische Physik fester Stoffe, Noethnitzer Strasse 40, 01187 Dresden (Germany); Department of Chemistry, Moscow State University, Moscow 119992 (Russian Federation); Van Tendeloo, G. [EMAT, University of Antwerp, Antwerp B-2020 (Belgium); Antipov, E.V. [Department of Chemistry, Moscow State University, Moscow 119992 (Russian Federation); Grin, Yu. [Max-Planck-Institut fuer Chemische Physik fester Stoffe, Noethnitzer Strasse 40, 01187 Dresden (Germany)

2006-09-15T23:59:59.000Z

202

Design and fabrication of a bending rotation fatigue test rig for in situ electrochemical analysis during fatigue testing of NiTi shape memory alloy wires  

Science Journals Connector (OSTI)

The current investigation proposes a novel method for simultaneous assessment of the electrochemical and structural fatigue properties of nickel-titanium shape memory alloy (NiTi SMA) wires. The design and layout of an in situ electrochemical cell in a custom-made bending rotation fatigue (BRF) test rig is presented. This newly designed test rig allows performing a wide spectrum of experiments for studying the influence of fatigue on corrosion and vice versa. This can be achieved by performing ex situ and/or in situ measurements. The versatility of the combined electrochemical/mechanical test rig is demonstrated by studying the electrochemical behavior of NiTi SMA wires in 0.9% NaCl electrolyte under load. The ex situ measurements allow addressing various issues for example the influence of pre-fatigue on the localized corrosion resistance or the influence of hydrogen on fatigue life. Ex situ experiments showed that a pre-fatigued wire is more susceptible to localized corrosion. The synergetic effect can be concluded from the polarization studies and specifically from an in situ study of the open circuit potential (OCP) transients which sensitively react to the elementary repassivation events related to the local failure of the oxide layer. It can also be used as an indicator for identifying the onset of the fatigue failure.

Jenni Kristin Zglinski; Matthias Frotscher

2013-01-01T23:59:59.000Z

203

Design and fabrication of a bending rotation fatigue test rig for in situ electrochemical analysis during fatigue testing of NiTi shape memory alloy wires  

SciTech Connect

The current investigation proposes a novel method for simultaneous assessment of the electrochemical and structural fatigue properties of nickel-titanium shape memory alloy (NiTi SMA) wires. The design and layout of an in situ electrochemical cell in a custom-made bending rotation fatigue (BRF) test rig is presented. This newly designed test rig allows performing a wide spectrum of experiments for studying the influence of fatigue on corrosion and vice versa. This can be achieved by performing ex situ and/or in situ measurements. The versatility of the combined electrochemical/mechanical test rig is demonstrated by studying the electrochemical behavior of NiTi SMA wires in 0.9% NaCl electrolyte under load. The ex situ measurements allow addressing various issues, for example, the influence of pre-fatigue on the localized corrosion resistance, or the influence of hydrogen on fatigue life. Ex situ experiments showed that a pre-fatigued wire is more susceptible to localized corrosion. The synergetic effect can be concluded from the polarization studies and specifically from an in situ study of the open circuit potential (OCP) transients, which sensitively react to the elementary repassivation events related to the local failure of the oxide layer. It can also be used as an indicator for identifying the onset of the fatigue failure.

Neelakantan, Lakshman [Ruhr-Universitaet Bochum, Institute for Materials, 44801 Bochum (Germany); Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, 600 036 Chennai (India); Zglinski, Jenni Kristin; Eggeler, Gunther [Ruhr-Universitaet Bochum, Institute for Materials, 44801 Bochum (Germany); Frotscher, Matthias [Ruhr-Universitaet Bochum, Institute for Materials, 44801 Bochum (Germany); CORTRONIK GmbH, 18119 Rostock-Warnemuende (Germany)

2013-03-15T23:59:59.000Z

204

Syngas production from glycerol-dry(CO2) reforming over La-promoted Ni/Al2O3 catalyst  

Science Journals Connector (OSTI)

Abstract A 3 wt% La-promoted Ni/Al2O3 catalyst was prepared via wet co-impregnation technique and physicochemically-characterized. Lanthanum was responsible for better metal dispersion; hence higher BET specific surface area (96.0 m2 g?1) as compared to the unpromoted Ni/Al2O3 catalyst (85.0 m2 g?1). In addition, the La-promoted catalyst possessed finer crystallite size (9.1 nm) whilst the unpromoted catalyst measured 12.8 nm. Subsequently, glycerol dry reforming was performed at atmospheric pressure and temperatures ranging from 923 to 1123 K employing CO2-to-glycerol ratio from zero to five. Significantly, the reaction results have yielded syngas as main gaseous products with H2:CO ratios always below than 2.0 with concomitant maximum 96% glycerol conversion obtained at the CO2-to-glycerol ratio of 1.67. In addition, the glycerol consumption rate can be adequately captured using power law modelling with the order of reactions equal 0.72 and 0.14 with respect to glycerol and CO2 whilst the activation energy was 35.0 kJ mol?1. A 72 h longevity run moreover revealed that the catalyst gave a stable catalytic performance.

Kah Weng Siew; Hua Chyn Lee; Jolius Gimbun; Sim Yee Chin; Maksudur R. Khan; Yun Hin Taufiq-Yap; Chin Kui Cheng

2015-01-01T23:59:59.000Z

205

Substrate orientation effects on the nucleation and growth of the M{sub n+1}AX{sub n} phase Ti{sub 2}AlC  

SciTech Connect

The M{sub n+1}AX{sub n} (MAX) phases are ternary compounds comprising alternating layers of a transition metal carbide or nitride and a third ''A-group'' element. The effect of substrate orientation on the growth of Ti{sub 2}AlC MAX phase films was investigated by studying pulsed cathodic arc deposited samples grown on sapphire cut along the (0001), (1010), and (1102) crystallographic planes. Characterization of these samples was by x-ray diffraction, atomic force microscopy, and cross-sectional transmission electron microscopy. On the (1010) substrate, tilted (1018) growth of Ti{sub 2}AlC was found, such that the TiC octahedra of the MAX phase structure have the same orientation as a spontaneously formed epitaxial TiC sublayer, preserving the typical TiC-Ti{sub 2}AlC epitaxial relationship and confirming the importance of this relationship in determining MAX phase film orientation. An additional component of Ti{sub 2}AlC with tilted fiber texture was observed in this sample; tilted fiber texture, or axiotaxy, has not previously been seen in MAX phase films.

Tucker, Mark D.; Guenette, Mathew C.; Bilek, Marcela M. M.; McKenzie, David R. [School of Physics, University of Sydney, New South Wales 2006 (Australia); Persson, Per O. A.; Rosen, Johanna [School of Physics, University of Sydney, New South Wales 2006 (Australia); Thin Film Physics, Linkoepings Universitet, 58183 Linkoeping (Sweden)

2011-01-01T23:59:59.000Z

206

E-Print Network 3.0 - al si ti Sample Search Results  

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

and SiC. Internal grains of SiC and kamaciteiron silicide are also found independent of TiC. The grain... by volume. V and Si were also present in ... Source: Washington...

207

Microstructures and wear properties of TiN-based cermet coating deposited on 1Cr18Ni9Ti stainless steel by electrospark process  

Science Journals Connector (OSTI)

A simple and effective surface treatment technique, electrospark deposition (ESD), has been successfully applied to deposit TiN-based cermet coating on stainless steel substrate. The nitrided coating had an average thickness of about 30 ?m and formed metallurgical bonding with the substrate. The microstructure of the coating was mainly composed of TiN phase and ferrite (?-FeCr) phase. Its microhardness reached 889HV. The experimental results demonstrated that the nitrided coating had an excellent sliding wear resistance because the hard TiN phase distributed in the coating increased the resistance to micro-cutting and plowing during the sliding wear test, which effectively improves the surface performance of stainless steel substrate.

X. Li; D.Q. Sun; X.Y. Zheng; Z.A. Ren

2008-01-01T23:59:59.000Z

208

Aluminium depletion in NiCrAlY bond coatings by hot corrosion as a function of projection system  

Science Journals Connector (OSTI)

Three different projection system are used to prepare NiCrAlY bond coats over metallic substrates: atmospheric plasma spray (APS), high velocity oxyfuel (HVOF) and high frequency pulse detonation (HFPD). These coatings were tested in hot corrosion experiments with sprayed Na2SO4 at 1000 °C for 20 and 100 h experiments in air. Coatings surface composition after thermal treatment was characterised by XRD and SEM. Cross section of coatings were analysed by SEM-EDX. A relationship between microstructural characteristics of initial coatings and final performance in hot corrosion was found in terms of porosity percentage: plasma sprayed coatings present higher percentage of porosity compared to HVOF and HFPD projection systems for the same composition and Al is heavily consumed in interparticle oxidation. This Al depletion in turn involves intrinsic chemical failure and surface layer is comprised by a porous spinel of mixed oxides. On the other hand, high energy projection systems produce dense coatings allowing the Al migration to external alumina layer, particularly in the case of HVOF coating.

M.C. Mayoral; J.M. Andrés; M.T. Bona; V. Higuera; F.J. Belzunce

2008-01-01T23:59:59.000Z

209

Comparative Studies on Temperature Dependent I-V Characteristics of Al/(p)CdTe and Ni/(n)CdS Schottky Junctions and Their PV Effect  

SciTech Connect

Temperature dependent I-V characteristics of vacuum evaporated Al/(p)CdTe and Ni/(n)CdS Schottky junctions and their photovoltaic effects have been studied and compared. Different junction parameters such as ideality factors, barrier heights, Richardson's constant, short-circuit current density, fill factor, PV efficiency etc. were determined from their I-V characteristics. These parameters were found to change significantly on variation of temperature. The structures showed the change of PV effect. Efficiency found were 2.84% for Al/(p)CdTe and 4.44% for Ni hydro/(n)CdS. Polycrystalline nature, and continuous and ordered structure with bigger grain sizes of the CdS film shows more PV conversion efficiency in making Ni/(n)CdS junction as compare to Al/(p)CdTe junction. However these values were found to vary with doping concentration, and in hydrogen treated samples in both cases.

Wary, G. [Department of Physics, Cotton College, Guwahati-781001 (India); Kachari, T.; Rahman, A. [Department of Physics, Gauhati University, Guwahati-781014 (India)

2010-06-29T23:59:59.000Z

210

Growth of individual carbon nanotubes on an array of TiN/Ni nanodots patterned by e-beam lithography and defined by dry etching for field emission application.  

E-Print Network (OSTI)

: Individual vertically aligned carbon nanotubes, Electron-beam lithography, Dry etching, Field emission and uniform electronic emission, cathodes based on vertically aligned carbon nanotubes (VACNTs) are patternedGrowth of individual carbon nanotubes on an array of TiN/Ni nanodots patterned by e

Boyer, Edmond

211

Conducting and insulating LaAlO{sub 3}/SrTiO{sub 3} interfaces: A comparative surface photovoltage investigation  

SciTech Connect

Surface photovoltage (SPV) spectroscopy, which is a versatile method to analyze the energetic distribution of electronic defect states at surfaces and interfaces of wide-bandgap semiconductor (hetero-)structures, is applied to comparatively investigate heterostructures made of 5-unit-cell-thick LaAlO{sub 3} films grown either on TiO{sub 2}- or on SrO-terminated SrTiO{sub 3}. As shown in a number of experimental and theoretical investigations in the past, these two interfaces exhibit dramatically different properties with the first being conducting and the second insulating. Our present SPV investigation reveals clearly distinguishable interface defect state distributions for both configurations when interpreted within the framework of a classical semiconductor band scheme. Furthermore, bare SrTiO{sub 3} crystals with TiO{sub 2} or mixed SrO/TiO{sub 2} terminations show similar SPV spectra and transients as do LaAlO{sub 3}-covered samples with the respective termination of the SrTiO{sub 3} substrate. This is in accordance with a number of recent works that stress the decisive role of SrTiO{sub 3} and the minor role of LaAlO{sub 3} with respect to the electronic interface properties.

Beyreuther, E., E-mail: elke.beyreuther@iapp.de; Thiessen, A.; Grafström, S.; Eng, L. M. [Institut für Angewandte Photophysik, Technische Universität Dresden, D-01062 Dresden (Germany); Paparo, D. [CNR-SPIN and Dipartimento di Fisica, Università di Napoli “Federico II,” Compl. Univ. di Monte S. Angelo, via Cintia, I-80126 Napoli (Italy)

2013-12-28T23:59:59.000Z

212

Dissimilar-alloy laser welding of titanium: Ti6Al-4V to Beta-C{trademark}  

SciTech Connect

Beta-C{sup TM} is a metastable-beta titanium alloy (nominal composition: Ti-3wt%Al-8wt%V-6wtTCr-4wt%Mo-4wt%Zr) which can be thermomechanically processed and heat treated to provide excellent combinations of strength, ductility, and fracture toughness. Recently, the increased application of metastable-beta titanium alloys in aerospace and commercial applications has resulted in the necessity to join these alloys to conventional alpha-beta titanium alloys. Based on this previous work, two approaches were considered for improving the ductility of dissimilar-alloy welds between Ti-6Al-4V and Beta-C{sup TM} in the present study: (1) application of a low heat input welding process to minimize the fusion zone and heat-affected zone (HAZ) beta grain size and (2) modification of the fusion zone chemical composition to allow greater microstructural optimization through postweld aging. CO{sub 2} laser welds were produced between Ti-6Al-4V and Beta-C{sup TM} sheet. Three different nominal fusion zone chemical compositions were obtained by varying the laser beam locations relative to the joint centerline and thereby melting different quantities of each base metal. For comparable postweld aging conditions, the laser welds exhibited ductilities superior to those of coarse-grained gas tungsten arc welds. Fracture analysis of the weld zone revealed a transition from a predominantly transgranular fracture in the low-temperature aged conditions to increasingly intergranular fracture following aging at higher temperature. This transition was promoted by an increase in the thickness and continuity of alpha phase at beta grain boundaries.

Liu, P.S.; Baeslack, W.A. III; Hurley, J.

1994-12-31T23:59:59.000Z

213

Comparison of \\{WTi\\} and WTi(N) as diffusion barriers for Al and Cu metallization on Si with respect to thermal stability and diffusion behavior of Ti  

Science Journals Connector (OSTI)

Abstract The thermal stability of \\{WTi\\} and WTi(N) as diffusion barriers for Al and Cu metallization on Si (1 0 0) was investigated by time of flight secondary ion mass spectrometry (ToF-SIMS) depth profiling, X-ray diffraction (XRD), electron microscopy (SEM and TEM) and X-ray photoelectron spectroscopy (XPS). For both, Al and Cu, Ti diffusion out of \\{WTi\\} into the metal was proved to occur at elevated temperatures (400 °C for Al and 600 °C for Cu) which further results in barrier film failure. Nitrogen incorporation into \\{WTi\\} leads to an elimination of the Ti diffusion and consequently to a better thermal stability of the barrier film. It is shown that besides crystal structure, Ti diffusion into the metallization is an essential factor of the barrier failure mechanism. The failure temperature for Al is lower than for Cu.

M. Fugger; M. Plappert; C. Schäffer; O. Humbel; H. Hutter; H. Danninger; M. Nowottnick

2014-01-01T23:59:59.000Z

214

Maximum Hydrogen Production by Autothermal Steam Reforming of Bio-oil With NiCuZnAl Catalyst  

Science Journals Connector (OSTI)

Autothermal steam reforming (ATR) of bio-oil, which couples the endothermic steam reforming reaction with the exothermic partial oxidation, offers many advantages from a technical and economic point of view. Effective production of hydrogen through ATR of bio-oil was performed at lower temperature with NiCuZnAl catalyst. The highest hydrogen yield from bio-oil reached 64.3% with a nearly complete bio-oil conversion at 600 °C, the ratio of steam to carbon fed (S/C) of 3 and the oxygen to carbon ratio (O/C) of 0.34. The reaction conditions in ATR including temperature, O/C, S/C and weight hourly space velocity can be used to control both hydrogen yield and products distribution. The comparison between the ATR and common steam reforming of bio-oil was studied. The mechanism of the ATR of bio-oil was also discussed.

Shi-zhi Yan; Qi Zhai; Quan-xin Li

2012-01-01T23:59:59.000Z

215

Octahedral rotations in strained LaAlO{sub 3}/SrTiO{sub 3} (001) heterostructures  

SciTech Connect

Many complex oxides display an array of structural instabilities often tied to altered electronic behavior. For oxide heterostructures, several different interfacial effects can dramatically change the nature of these instabilities. Here, we investigate LaAlO{sub 3}/SrTiO{sub 3} (001) heterostructures using synchrotron x-ray scattering. We find that when cooling from high temperature, LaAlO{sub 3} transforms from the Pm3{sup ¯}m to the Imma phase due to strain. Furthermore, the first 4 unit cells of the film adjacent to the substrate exhibit a gradient in rotation angle that can couple with polar displacements in films thinner than that necessary for 2D electron gas formation.

Fister, T. T.; Hruszkewycz, S. O.; Proffit, D. L.; Eastman, J. A.; Fuoss, P. H.; Baldo, P. M.; Fong, D. D. [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Zhou, H. [X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Luo, Z. [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 (China); Seo, S. S. A.; Lee, H. N. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

2014-02-01T23:59:59.000Z

216

Influence of MgO in the CO2 – steam reforming of methane to syngas by NiO/MgO/ ?-Al2O3 catalyst  

Science Journals Connector (OSTI)

Simultaneous steam and CO2 reforming of methane to syngas (H2and CO) over NiO/MgO/a-Al2O3 catalyst have been investigated at different MgO wt.%. The catalyst has been characterized by temperature-programmed reduc...

Jafar Yeganeh Mehr; Kheirolah Jafari Jozani…

2002-03-01T23:59:59.000Z

217

Combined Steam and Carbon Dioxide Reforming of Methane on Ni/MgAl2O4: Effect of CeO2 Promoter to Catalytic Performance  

Science Journals Connector (OSTI)

The catalytic performance during combined steam and carbon dioxide reforming of methane (SCR) was investigated on Ni/MgAl2O4 catalyst promoted with CeO2. The SCR catalyst was prepared by co-impregnation method us...

Seung-Chan Baek; Jong-Wook Bae; Joo Yeong Cheon; Ki-Won Jun…

2011-02-01T23:59:59.000Z

218

Air stable Al2O3-coated Li2NiO2 cathode additive as a surplus current consumer in a Li-ion cell  

E-Print Network (OSTI)

cathode additive is prepared by coating with Al iso-propoxide on Li2NiO2, obtained from firing exothermic reaction with an electrolyte during the overcharging process, which may result in a short-circuiting of the cell.5­9 A combination of the temperature increase and the internal short circuit of the cell

Cho, Jaephil

219

Investigation of the hydroconversion of rancid lard and lard-gas oil mixture on NiMo/Al2O3 catalyst in oxide and in sulphide state  

Science Journals Connector (OSTI)

The necessity to maintain mobility and the increasing energy- and environmentally sound demands necessitated the research, development and utilization of engine fuels from renewable resources. Because of the negative features of the already and generally ... Keywords: NiMo/Al2O3, hydroconversion, hydrogenation, lard, triglyceride

P. Baladincz; J. Hancsók

2011-12-01T23:59:59.000Z

220

CO impurities effect on LaNi4.7Al0.3 hydrogen storage alloy hydrogenation/dehydrogenation properties  

E-Print Network (OSTI)

1 CO impurities effect on LaNi4.7Al0.3 hydrogen storage alloy hydrogenation thermal analyses (TG+DTA). The hydrogen storage properties were studied by the pressure in hydrogen containing 300 ppm CO at 30 ºC, but hydrogen storage capacity didn't degrade when tested at 80 º

Volinsky, Alex A.

Note: This page contains sample records for the topic "ni ti al" 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

PII S0016-7037(99)00244-6 The role of Al in the formation of secondary Ni precipitates  

E-Print Network (OSTI)

is dissolved from the sorbent and substitutes for Ni in brucite-like hydroxide layers of the newly forming

Sparks, Donald L.

222

Modulation of conductance and superconductivity by top-gating in LaAlO{sub 3}/SrTiO{sub 3} 2-dimensional electron systems  

SciTech Connect

We report the electrical top-gating of a 2-dimensional electron gas (2DEG) formed at the LaAlO{sub 3}/SrTiO{sub 3} interface, using electron-beam evaporated Au gate electrodes. In these structures, epitaxial LaAlO{sub 3} films grown by pulsed laser deposition induce the 2DEGs at the interface to the SrTiO{sub 3} substrate and simultaneously act as the gate dielectric. The structured top-gates enable a local tuning and complete on/off switching of the interface (super-)conductivity, while maintaining the usual, intrinsic characteristics for these LaAlO{sub 3}/SrTiO{sub 3} interfaces when no gate voltage is applied.

Eerkes, P. D.; Wiel, W. G. van der; Hilgenkamp, H. [MESA Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands)] [MESA Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands)

2013-11-11T23:59:59.000Z

223

Epitaxial \\{MCrAlY\\} coating on a Ni-base superalloy produced by electrospark deposition  

Science Journals Connector (OSTI)

Abstract A novel electrospark deposition technique has been successfully developed to deposit epitaxially \\{MCrAlY\\} coating onto a directionally solidified nickel base superalloy. The coating is featured by cellular directionally solidified microstructure with primary ? phase. Its formation mechanism may be attributed to the facts that the alloy solidifies primarily with ? phase and solidification conditions of the tiny thin melt close to the limit of constitutional undercooling under the electrospark treatment condition.

Yu-jiang Xie; Mao-cai Wang

2006-01-01T23:59:59.000Z

224

NOIIVUISINII/UQV NOIlVIAIdOdNI AOH3N3 SNOLL33fOHcI AlHHXHVnO  

Gasoline and Diesel Fuel Update (EIA)

NOIIVUISINII/UQV NOIlVIAIdOdNI AOH3N3 NOIIVUISINII/UQV NOIlVIAIdOdNI AOH3N3 SNOLL33fOHcI AlHHXHVnO xoonno AOHHNH T €661 This publication and other Energy Information Administration (EIA) publications may be purchased from the Superintendent of Documents, U.S. Government Printing Office. All telephone orders should be directed to: U.S. Government Printing Office Superintendent of Documents McPherson Square Bookstore U.S. Government Printing Office 1510 H Street, N.W. Washington, DC 20402

225

Washing Effect of a LiNi0.83Co0.15Al0.02O2 Cathode in Water Jisuk Kim,a  

E-Print Network (OSTI)

high capacity active materials, such as Si, Sn, or LiNi1-x-yCoxMnyO2 with a 4.2 V cutoff.1-5 OneWashing Effect of a LiNi0.83Co0.15Al0.02O2 Cathode in Water Jisuk Kim,a Youngsik Hong,b,d Kwang Sun mAh Li-ion cell was commercialized in 2004. Despite the fact that the electrode materials used were

Cho, Jaephil

226

Precipitation behavior of Ni-Cr-22 Fe-18 Mo (Hastelloy-X) and Ni-Cr-22 Co-12 Mo (Inconel-617) after isothermal aging  

SciTech Connect

The precipitation behavior of the nickel-base alloys Ni-Cr-22Fe-18Mo (Hastelloy-X) and Ni-Cr-22Co12Mo (Inconel-617) has been investigated as a function of aging temperature. Hastelloy-X shows that M/sub 6/C and TiN are primary precipitates and M/sub 12/C, A/sub 3/B/sub 2/ (approx. = Fe/sub 3/Mo/sub 2/), and M/sub 23/C/sub 6/ are secondary precipitates, while Inconel-617 also has M/sub 6/C and TiN as primary precipitates and M/sub 23/C/sub 6/, M/sub 12/C, and Ni/sub 3/AlTi as secondary precipitates. The characterization has been carried out by metallographic and transmission electron microscopy investigations and by x-ray examinations of electrochemical isolated precipitates.

Kirchhofer, H.; Nickel, H.; Schubert, F.

1984-07-01T23:59:59.000Z

227

Selective Laser Melting Additive Manufacturing of TiC/AlSi10Mg Bulk-form Nanocomposites with Tailored Microstructures and Properties  

Science Journals Connector (OSTI)

Abstract The nanoscale TiC particle reinforced AlSi10Mg nanocomposite parts were produced by selective laser melting (SLM) additive manufacturing process. The influence of laser energy density (LED) on densification behavior, microstructural evolution, microhardness and wear properties of SLM-processed TiC/AlSi10Mg nanocomposites was studied. It showed that the near fully dense nanocomposite parts (>98% theoretical density) were achieved with increasing the applied LED. The TiC reinforcement in SLM-processed parts experienced a microstructural change from the standard nanoscale particle morphology (the average size 77-93 nm) to the relatively coarsened submicron structure (the mean particle size 154 nm) as the LED increased.The sufficiently high densification rate combined with the homogeneousdistribution of nanoscale TiC reinforcement throughout the matrix led to a high microhardness of 181.2 HV0.2, a considerably low coefficient of friction (COF) of 0.36, and a reduced wear rate of 2.94×10-5 mm3N-1m-1 for SLM-processed TiC/AlSi10Mg nanocomposite parts.

Dongdong Gu; Hongqiao Wang; Fei Chang; Donghua Dai; Pengpeng Yuan; Yves-Christian Hagedorn; Wilhelm Meiners

2014-01-01T23:59:59.000Z

228

A Successful Synthesis of the CoCrFeNiAl{sub 0.3} Single-Crystal, High-Entropy Alloy by Bridgman Solidification  

SciTech Connect

For the first time, a face-centered-cubic, single-crystal CoCrFeNiAl{sub 0.3} (designated as Al0.3), high-entropy alloy (HEA) was successfully synthesized by the Bridgman solidification (BS) method, at an extremely low withdrawal velocity through a constant temperature gradient, for which it underwent two BS steps. Specially, at the first BS step, the alloy sample underwent several morphological transitions accompanying the crystal growth from the melt. This microstructure evolves from as-cast dendrites, to equiaxed grains, and then to columnar crystals, and last to the single crystal. In particular, at the equiaxed-grain region, some visible annealing twins were observed, which indicates a low stacking fault energy of the Al0.3 alloy. Although a body-centered- cubic CoCrFeNiAl (Al1) HEA was also prepared under the same conditions, only a single columnar-crystal structure with instinctively preferential crystallographic orientations was obtained by the same procedure. A similar morphological transition from dendrites to equiaxed grains occurred at the equiaxed-grain region in Al1 alloy, but the annealing twins were not observed probably because a higher Al addition leads to a higher stacking fault energy for this alloy.

Ma, S. G.; Zhang, S. F.; Gao, M. C.; Liaw, P. K.; Zhang, Y.

2013-12-01T23:59:59.000Z

229

Stability of the L1{sub 2} phase at 800 C in the Ti-Al-Cr system  

SciTech Connect

Interest in the L1{sub 2} phase, in the Ti-Al-Cr ternary system, continues due to the search for enhanced mechanical properties in light weight materials for possible structural applications. Additionally, recent work has indicated that alloys based in part on this phase may find use as protective alumina-forming coatings for {gamma}-based titanium-aluminides. In order to aid in the development of structural materials and coatings, the actual phase equilibria must be determined so that the correct processing schemes may be designed. Towards this end, the present work seeks to clarify some of the confusion pertaining to the phase equilibria of the L1{sub 2} phase.

Jewett, T.J.; Ahrens, B. [GKSS Research Centre, Geesthacht (Germany)] [GKSS Research Centre, Geesthacht (Germany); Dahms, M. [FH-Flensburg (Germany)] [FH-Flensburg (Germany)

1996-02-01T23:59:59.000Z

230

Solution Processed Al-Doped ZnO Nanoparticles/TiOx Composite for Highly Efficient Inverted Organic Solar Cells  

Science Journals Connector (OSTI)

Solution Processed Al-Doped ZnO Nanoparticles/TiOx Composite for Highly Efficient Inverted Organic Solar Cells ... This metal-oxide composition, called AZOTi, has two important elements that benefit production of low cost devices. ... After successful utilization of AZOTi in the fabrication of optimized single layer P3HT/PCBM-inverted solar cells, we also fabricated tandem cells comprising ITO/AZOTi/P3HT/PCBM in the front cell and a blend of a low band gap polymer [2,1,3-benzothiadiazole-4,7-diyl [4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b:3,4-b?]dithiophene-2,6-diyl

Abay Gadisa; Travis Hairfield; Leila Alibabaei; Carrie L. Donley; Edward T. Samulski; Rene Lopez

2013-08-27T23:59:59.000Z

231

Feasibility study on preparation of coatings on Ti–6Al–4V by combined ultrasonic impact treatment and electrospark deposition  

Science Journals Connector (OSTI)

Abstract A novel method combining ultrasonic impact treatment (UIT) with electrospark deposition was developed to prepare coatings on Ti–6Al–4V substrates. The microstructure, phase composition, residual stress, microhardness, and wear performance of the coating were studied, and new amorphous and nanocrystalline phases (titanium carbide nitride and iron titanium oxide) were found. In addition, the residual stress in the coating and in the substrate near the coating is compressive stress. The maximum compressive residual stress is about ?717 MPa, and its depth is about 470 ?m. Because of contributions from multiple factors, the wear volume loss of the sample subjected to combined UIT and electrospark processing was reduced by four orders of magnitude compared with that of the base material.

Yang Liu; Dongpo Wang; Caiyan Deng; Lixing Huo; Lijun Wang; Shu Cao

2014-01-01T23:59:59.000Z

232

Formation mechanism of linear friction welded Ti-6Al-4V alloy joint based on microstructure observation  

SciTech Connect

The microstructure of the linear friction welded Ti-6Al-4V titanium alloy joint was investigated by optical microscope, scanning electronic microscope and transmission electron microscope. Results show that the dynamic recovery and recrystallization resulting from the intensive plastic deformation and fast heating and cooling processes during linear friction welding account for the superfine {alpha} + {beta} grains in the weld center. Fine {alpha} grains distribute in the {beta} matrix or at the boundaries of {beta} grains. A mass of dislocations networks and metastructures present within the {alpha} and {beta} grains. - Research Highlights: {yields} TEM is employed in the analysis. {yields} The dynamic recovery is the main mechanism in thermal deformation of TC4. {yields} Superfine grains in the weld result from dynamic recovery and dynamic recrystallizaion, but the recrystallization is inadequate.

Ma Tiejun; Chen Tao, E-mail: ctwc-13@163.com; Li Wenya; Wang Shiwei; Yang Siqian

2011-01-15T23:59:59.000Z

233

Microstructures and mechanical properties of Ti-6Al-4V welds with filler additions of tantalum and FS85  

SciTech Connect

Many applications in the nuclear industry require that titanium alloys be welded to refractory metal alloys. Because of the widely dissimilar properties of these materials, the homogeneity of the fusion zone os of particular concern. To address this issue, a study was conducted to characterize the fusion zones of Ti-6Al-4V welds made with filler additions of tantalum and FS85 (Nb-28Wt%Ta-10wt%W-1wt%Zr). A goal of this study was to evaluate the feasibility of making microstructural predictions based on calculated fusion zone electron/atom (e/a) ratios. The welds were made by placing tantalum or FS85 shims between two pieces of 2.5 mm (0.1 in.) thick Ti-6Al-4V and making an electron beam weld along the length of the shim. With complete mixing, these shims were expected to produce fusion zone e/a ratios of 3.63{emdash}4.14 for the Ta series and 3.63{emdash}4.06 for the FS85 series, and microstructures consisting of {alpha}`, {alpha}`, and perhaps {omega}. The weld macro- and microstructures were characterized using optical and electron microscopy, energy-dispersive spectroscopy, and x-ray diffraction. The mechanical properties of the welds were assessed using transverse and all-weld-metal tensile tests. The results showed a general increase in strength and decrease in ductility with increasing {beta} stabilizer level. As a result of this study, parameters were developed to increase the fusion zone size and increase mixing of the components. This work was performed at Sandia National Laboratories, supported by the U.S. Department of Energy under contract number DE-AC04-76DR00789, and at Los Alamos National Laboratory under contract number W-7405-ENG-36.

Damkroger, B.K.; Dixon, R.D.; Cotton, J.D.

1994-12-31T23:59:59.000Z

234

Plasma-sprayed CaTiSiO5 ceramic coating on Ti-6Al-4V with excellent bonding strength, stability and cellular bioactivity  

Science Journals Connector (OSTI)

...doi:10.1016/j.biomaterials.2004.09.019 . Wu, C , J Chang, S Ni, and J Wang2006 In vitro bioactivity of akermanite ceramics. J. Biomed. Mater. Res. A. 76, 73-80. Wu, C , J Chang, W Zhai, and S NiA novel bioactive porous bredigite...

2009-01-01T23:59:59.000Z

235

Characterization of solid-phase welds between Ti-6Al-2Sn-4Zr-2Mo-0. 01Si and Ti-13. 5A1-21. 5Nb titanium aluminide  

SciTech Connect

Dissimilar-alloy welds have been produced between Ti-6Al-2Sn-4Zr-2Mo-0.1Si (wt.%) and Ti-13.5Al-21.5Nb (wt.%) titanium aluminide using three different solid-phase welding processes that create significantly different thermo-mechanical conditions at the weld interface. Exposure to supertransus temperatures, appreciable deformation and rapid cooling of the weld interface region during linear-friction welding promote dynamic recrystallization of beta grains and beta decomposition to fine martensitic products. In contrast, diffusion welding at temperatures below the base metal beta transus temperatures and at relatively low pressures minimizes deformation and microstructural variations in the weld interface region relative to the unaffected base metal. During capacitor-discharge resistance spot welding, extremely rapid heating of the weld interface region to near-solidus temperatures, and subsequent rapid cooling, result in the formation of a metastable, ordered-beta microstructure in the Ti-13.5ASl-21.5Nb and fine alpha-prime martensite in the Ti-6Al-2Sn-4Zr-2Mo-0.1Si.

Baeslack, W.A. III; Juhas, M.; Fraser, H.L. (Ohio State Univ., Columbus, OH (United States)); Broderick, T.F. (Wright Labs., Wright Patterson AFB, OH (United States). Materials Directorate)

1994-12-01T23:59:59.000Z

236

Ti-based composite coatings with gradient TiC x reinforcements on TC4 titanium alloy prepared by laser cladding  

Science Journals Connector (OSTI)

TiC x -NiTi2/Ti cermet composite coatings C1 and C2 with gradient TiC x ...reinforcements were prepared on TC4 titanium alloy by laser cladding ...

ShuNv Liu; ZongDe Liu; Yang Wang; Peng Yue

2014-07-01T23:59:59.000Z

237

Photoelectrocatalytic degradation of acid dye using Ni–TiO2 with the energy supplied by solar cell: Mechanism and economical studies  

Science Journals Connector (OSTI)

This paper reports an investigation into the effect of a number of operating factors on the removal of Acid Red 88 from an aqueous solution through photoelectrocatalysis: photocatalyst dose, dye concentration, pH, bias potential, and electrolyte concentration. The photocatalyst was Ni–TiO2 applied in suspension to the solution to achieve a larger catalyst surface area. The optimum values for photocatalyst dose, dye concentration, and electrolyte concentration turned out to be 0.6 mg L?1, 50 mg L?1, and 5 mg L?1, respectively. Also, the best pH was found to be 7, and bias potential proved to be best at 1.6 V. The aqueous solution was characterized for its COD and TOC. Photocatalyst efficiency was evaluated using SEM and XRD techniques. The characterization of the post-treatment product using FT-IR, HPLC, and GC-MS studies revealed intermediate compounds. A pathway was proposed for the degradation of the dye. The energy required by the experiment was supplied by solar cells, meaning the money that would have otherwise been spent on electricity was saved. Cost analysis was also done for the treatment process.

Mohammad Ebrahim Olya; Azam Pirkarami; Majid Soleimani; Manochehr Bahmaei

2013-01-01T23:59:59.000Z

238

Influence of Sulfur on the Carbon Deposition in Liquid Hydrocarbon Steam Reforming over CeO2-Al2O3 supported Ni and Rh Catalysts  

SciTech Connect

This study was performed to elucidate the influence of sulfur on the carbon deposition in steam reforming of liquid hydrocarbons over CeO{sub 2}-Al{sub 2}O{sub 3} supported Ni and Rh catalysts at 800 C. The characteristics of the carbon deposits on the used catalysts after the reactions without and with sulfur were investigated by temperature-programmed oxidation (TPO), transmission electron microscopy (TEM), scanning transmission X-ray microscopy (STXM), temperature-programmed hydrogenation (TPH), X-ray absorption near edge structure (XANES), and scanning electron microscopy (SEM). Though abundant carbon deposits can accumulate on the pure CeO{sub 2}-Al{sub 2}O{sub 3} support due to fuel thermal cracking, the addition of Ni or Rh metal greatly reduced the carbon deposition in the sulfur-free reaction. The presence of sulfur increased the carbon deposition on both catalysts, which has a much more significant impact for the Ni catalyst. Carbon XANES study on the used catalysts revealed that graphitic carbon was dominant in the presence of sulfur, while oxidized carbon species (quinone-like carbon, carboxyl and carbonate) prevailed without sulfur. Meanwhile, the formation of carboxyl and carbonate more dramatically dropped on the Ni catalyst than that on the Rh catalyst. Our results strongly suggest that (I) the presence of sulfur can suppress carbon gasification and promote the formation of graphitic carbon on reforming catalysts due mainly to its poisoning effect on metals, and (II) Rh catalyst possesses stronger capability to maintain carbon gasification activity than Ni catalyst in the presence of sulfur.

C Xie; Y Chen; Y Li; X Wang; C Song

2011-12-31T23:59:59.000Z

239

Hydrogen production via CO2-reforming of methane over Cu and Co doped Ni/Al2O3 nanocatalyst: impregnation versus sol–gel method and effect of process conditions and promoter  

Science Journals Connector (OSTI)

In this study, Cu and Co doped Ni/Al2O3 nanocatalyst was synthesized via impregnation and sol–gel methods. The physiochemical properties of nanocatalyst were characterized by XRD, field emission scanning electron...

Seyed Mehdi Sajjadi; Mohammad Haghighi…

2013-09-01T23:59:59.000Z

240

Epitaxial growth of metastable multiferroic AlFeO{sub 3} film on SrTiO{sub 3} (111) substrate  

SciTech Connect

GaFeO{sub 3}-type AlFeO{sub 3} is consisted of oxygen octahedra and tetrahedra containing Al and Fe ions and is known to have a non-centrosymmetric polar structure with space group Pna2{sub 1}. We tried to grow epitaxial GaFeO{sub 3}-type AlFeO{sub 3} films on SrTiO{sub 3} (111) substrates by pulsed laser deposition technique. Both the atomic arrangement of close-packed and the atomic distance of the substrate surface played important roles in stabilizing GaFeO{sub 3}-type AlFeO{sub 3} on the substrate. Piezoresponse force microscopy measurements clearly showed that GaFeO{sub 3}-type AlFeO{sub 3} films have ferroelectricity at room temperature. In addition, AlFeO{sub 3} film also showed pinched-like hysteresis loop with T{sub N}???317?K.

Hamasaki, Yosuke; Shimizu, Takao; Taniguchi, Hiroki; Taniyama, Tomoyasu; Yasui, Shintaro; Itoh, Mitsuru, E-mail: itoh.m.aa@m.titech.ac.jp [Materials and Structures Laboratory, Tokyo Institute of Technology, 4259-J2-19 Nagatsuta-cho, Midori-ku, Yokohama 226-8503 (Japan)

2014-02-24T23:59:59.000Z

Note: This page contains sample records for the topic "ni ti al" 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

BaO/Al2O3/NiAl(110) Model NOx Storage Materials: the effect of BaO film thickness on the amorphous-to-crystalline Ba(NO3)2 phase transition  

SciTech Connect

The reaction of NO2 with BaO (0.15 – 2 ML and > 30 ML)/Al2O3(12 ML)/NiAl(110) model NOx storage materials was studied. A thick (~12 ML), ordered Al2O3 film was prepared as the support oxide on a NiAl(110) substrate in order to minimize the effect of the intermixing between the two oxide phases (BaO and Al2O3) on the NOx chemistry of BaO. The growth of a thick alumina film, prepared by atomic oxygen deposition onto NiAl(110), follows a layer-by-layer growth mode and the resulting film is much more stable when exposed to NO2 than the ultra-thin alumina films studied before. The interaction of NO2 with the model NOx storage systems at low coverages of BaO show fundamentally different behaviors from a thick BaO film, as nitrite species form at low exposures of NO2, followed by nitrate formation at high NO2 exposures. In contrast, on the thick BaO layer nitrite-nitrate ion pairs form at 300 K under UHV conditions (PNO2 ~ 1 ? 10-9 Torr). However, at elevated NO2 pressures (? 1 ? 10-5 Torr) the thick BaO film is gradually converted into amorphous Ba(NO3)2 at 300 K. Raising the temperature of the samples with ?BaO > 1 ML after NO2 exposure (in the absence of gas phase NO2) leads to the phase transformation of the amorphous Ba(NO3)2 layer into crystalline Ba(NO3)2 particles in the temperature range of 500 – 600 K. No phase transformation is observed in samples with ?BaO < 1 ML.

Yi, Cheol-Woo W.; Szanyi, Janos

2009-01-15T23:59:59.000Z

242

E-Print Network 3.0 - avastart ti traumade Sample Search Results  

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University of South Carolina Collection: Mathematics 15 Characterization of TiN, TiC and TiCN coatings on Ti50.6 at.% Ni alloy deposited by PIII and deposition technique...

243

Thermo-Mechanical Model Development and Validation of DirectedEnergy Deposition Additive Manufacturing of Ti-6Al-4V  

Science Journals Connector (OSTI)

Abstract A thermo-mechanical model of directed energy deposition additive manufacturing of Ti-6Al-4V is developed using measurements of the surface convection generated by gasses flowing during the deposition. In directed energy deposition, material is injected into a melt pool that is traversed to fill in a cross-section of a part, building it layer-by-layer. This creates large thermal gradients that generate plastic deformation and residual stresses. Finite element analysis (FEA) is often used to study these phenomena using simple assumptions of the surface convection. This work proposes that a detailed knowledge of the surface heat transfer is required to produce more accurate FEA results. The surface convection generated by the deposition process is measured and implemented in the thermo-mechanical model. Three depositions with different geometries and dwell times are used to validate the model using in situ measurements of the temperature and deflection as well as post-process measurements of the residual stress. An additional model is developed using the assumption of free convection on all surfaces. The results show that a measurement-based convection model is required to produce accurate simulation results.

J.C. Heigel; P. Michaleris; E.W. Reutzel

2014-01-01T23:59:59.000Z

244

Analysis of Wear Mechanisms in Low Friction, Nanocomposite AlMgB14-TiB2 Coatings  

SciTech Connect

Recent developments in coating science and technology offer new opportunities to enhance the energy-efficiency and performance of industrial machinery such as hydraulic fluid pumps and motors. The lubricated friction and wear characteristics of two wear-resistant coatings, diamond-like carbon and a nanocomposite material based on AlMgB{sub 14}-50 vol.% TiB{sub 2}, were compared in pin-on-disk tribotests using Mobil DTE-24{trademark} oil as the lubricant. In each case, the pins were fixed 9.53 mm diameter spheres of AISI 52100 steel, the load was 10 N, and the speed 0.5 m/s in all tests. Average steady-state friction coefficient values of 0.10 and 0.08 were measured for the DLC and nanocomposite, respectively. The coatings and their 52100 steel counterfaces were analyzed after the tests by X-ray photoelectron and Auger spectroscopy for evidence of material transfer or tribo-chemical reactions. The low-friction behavior of the boride nanocomposite coating is due to the formation of lubricative boric acid, B(OH){sub 3}. In contrast, the low-friction behavior of the DLC coating is related to the relatively low dielectric constant of the oil-based lubricant, leading to desorption of surface hydrogen from the coating.

Cook, Bruce A [Ames Laboratory; Harringa, J [Ames Laboratory; Anderegg, A [Ames Laboratory; Russell, A M [Iowa State University; Qu, Jun [ORNL; Blau, Peter Julian [ORNL; Higdon, Clifton [Eaton Corporation; Elmoursi, Alaa A [Eaton Corporation

2010-01-01T23:59:59.000Z

245

The Effect of Oxygen Contamination on the Amorphous Structure of Thermally Sprayed Coatings of Cu47Ti33Zr11Ni8Si1  

SciTech Connect

this research has shown that it is possible to deposit coatings of gas atomized Cu{sub 47}Ti{sub 33}Zr{sub 11}Ni{sub 8}Si{sub 1} powders containing various levels of oxygen contamination using plasma arc spray methods. The structure of the coating was found to depend primarily on the spray environment, with an argon atmosphere producing the most amorphous samples for a given starting powder. The oxygen content of the coatings reflected the relative levels of the oxygen contamination in the starting powders. The analysis of the starting powders displayed oxygen contents ranging from 0.125-0.79 wt.%. It was shown that higher oxygen levels lead to more crystalline structure in the starting powders as determined by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). This trend was found to be true for both the starting powders and for the plasma sprayed coatings. Chemical composition for all starting powders was very close to the nominal alloy composition. Chemical changes in the coatings involved the loss of Cu in coatings where high levels of oxidation were found. Cavitation erosion testing of selected coatings showed a weak trend that coatings prepared by vacuum plasma spray (VPS) had lower damage rates, but there was no clear data to indicate which coating parameters were superior. The range of data produced from testing duplicate coating was too wide to provide a good statistical measure of cavitation erosion resistance. of interest was the fact that when coatings began to show damage from cracking, all samples of a group showed similar damage and usually the damage pattern was somewhat unique to that group of samples. Failure of the coatings was due to features inherent to plasma arc spray (PAS) coating (i.e., pores, splat boundaries, oxide inclusions) rather than the mechanical characteristics of the amorphous alloy.

Matthew Frank Besser

2002-05-27T23:59:59.000Z

246

The Allende meteorite: evidence for a new cosmothermometer based on Ti3+/Ti4+  

Science Journals Connector (OSTI)

... 1,765 Perovskite CaTiO3 1,647 1,393 Melilite Ca2Al2SiO7- 1,625 1,450 Ca2MgSi2O7 Spinel MgAl2O4 1,513 1,362 Metallic iron Fe(Fe-Ni) 1,473 Diopside CaMgSi2O6 ... rhonite and fassaite compositions are for rhonites that have decomposed to fassaite + perovskite + spinel. Open circles represent intra-crystalline fassaites. The dashed line marked ALL-4 is the ...

Stephen E. Haggerty

1978-11-16T23:59:59.000Z

247

Syngas methanation for substitute natural gas over Ni–Mg/Al2O3 catalyst in fixed and fluidized bed reactors  

Science Journals Connector (OSTI)

Abstract A comparative study was conducted for laboratory syngas methanation over a self-made Ni–Mg/Al2O3 catalyst to demonstrate the technical advantages of fluidized bed over fixed bed reactor. At different reaction temperatures, gas velocities and pressures, the CO conversion and selectivity to CH4 in fluidized bed were shown to be higher than in fixed bed, and much closer to the thermodynamic equilibriums. The spent catalysts from fluidized bed methanation had distinctively low and easy-oxidizing deposited carbon in comparison with that from fixed bed. The results were attributed to the bigger effective catalytic surface, better heat and mass transfer in fluidized bed reactor.

Jiao Liu; Wenlong Shen; Dianmiao Cui; Jian Yu; Fabing Su; Guangwen Xu

2013-01-01T23:59:59.000Z

248

Evidence for viscous flow nature in Zr{sub 60}Al{sub 15}Ni{sub 25} metallic glass subjected to cold rolling  

SciTech Connect

The microstructure changes of Zr{sub 60}Al{sub 15}Ni{sub 25} metallic glass upon cold rolling and their influences on the thermally induced crystallization kinetics are investigated. The results show that atomic redistribution occurs within the localized zones in the glassy matrix, resulting from the softening of the shear modulus, which retards the crystallization behaviors during the subsequent heating. The present work provides direct evidence for the viscous flow nature in a metallic glass subjected to plastic deformation, during which the softened zones act as potential shear transformation zones.

Yan Zhijie [School of Materials Science and Engineering, Taiyuan University of Science and Technology, Taiyuan 030024 (China); IFW Dresden, Institut fuer Komplexe Materialien, Helmholtzstrasse 20, D-01069 Dresden (Germany); Hao Weixin; Hu Yong [School of Materials Science and Engineering, Taiyuan University of Science and Technology, Taiyuan 030024 (China); Song Kaikai; Eckert, Juergen [IFW Dresden, Institut fuer Komplexe Materialien, Helmholtzstrasse 20, D-01069 Dresden (Germany); TU Dresden, Institut fuer Werkstoffwissenschaft, D-01062 Dresden (Germany); Stoica, Mihai; Scudino, Sergio [IFW Dresden, Institut fuer Komplexe Materialien, Helmholtzstrasse 20, D-01069 Dresden (Germany)

2013-07-08T23:59:59.000Z

249

On the effect of deep-rolling and laser-peening on the stress-controlled low- and high-cycle fatigue behavior of Ti-6Al-4V at elevated temperatures up to 550?C  

E-Print Network (OSTI)

and near-?-titanium alloys, especially for fan bladebehavior of a titanium Ti-6Al-4V turbine fan blade alloy isfan blades and disks in aircraft jet propulsion engines are commonly made from titanium

Ritchie, IAltenberger, RKNalla, YSano LWagner, RO

2013-01-01T23:59:59.000Z

250

Observation of strontium segregation in LaAlO{sub 3}/SrTiO{sub 3} and NdGaO{sub 3}/SrTiO{sub 3} oxide heterostructures by X-ray photoemission spectroscopy  

SciTech Connect

LaAlO{sub 3} and NdGaO{sub 3} thin films of different thicknesses have been grown by pulsed laser deposition on TiO{sub 2}-terminated SrTiO{sub 3} single crystals and investigated by soft X-ray photoemission spectroscopy. The surface sensitivity of the measurements has been tuned by varying photon energy h? and emission angle ?. In contrast to the core levels of the other elements, the Sr 3d line shows an unexpected splitting for higher surface sensitivity, signaling the presence of a second strontium component. From our quantitative analysis we conclude that during the growth process Sr atoms diffuse away from the substrate and segregate at the surface of the heterostructure, possibly forming strontium oxide.

Treske, Uwe; Heming, Nadine; Knupfer, Martin; Büchner, Bernd; Koitzsch, Andreas, E-mail: a.koitzsch@ifw-dresden.de [Institute for Solid State Research, IFW-Dresden, P.O. Box 270116, DE-01171 Dresden (Germany); Di Gennaro, Emiliano; Scotti di Uccio, Umberto; Miletto Granozio, Fabio [CNR-SPIN and Dipartimento di Fisica, Complesso Universitario di Monte S. Angelo, Via Cintia, 80126 Naples (Italy); Krause, Stefan [Helmholtz-Zentrum Berlin, BESSY, Albert-Einstein-Str. 15, 12489 Berlin (Germany)

2014-01-01T23:59:59.000Z

251

Hydrogen production by steam reforming of liquefied natural gas (LNG) over mesoporous Ni–La–Al2O3 aerogel catalysts: Effect of La content  

Science Journals Connector (OSTI)

Mesoporous Ni–La–Al2O3 aerogel catalysts (denoted as (40-x)NixLa) with different lanthanum content (x) were prepared by a single-step sol-gel method and a subsequent CO2 supercritical drying method. The effect of lanthanum content on the physicochemical properties and catalytic performance of mesoporous (40-x)NixLa catalysts in the steam reforming of liquefied natural gas (LNG) was investigated. Physicochemical properties of (40-x)NixLa catalysts were strongly influenced by lanthanum content. Dispersion and reducibility of nickel aluminate phase in the (40-x)NixLa catalysts increased with increasing lanthanum content. Small amount of lanthanum addition was effective for dispersion of metallic nickel in the (40-x)NixLa catalysts, but large amount of lanthanum addition was not favorable for nickel dispersion due to the blocking of active sites. In the steam reforming of LNG, both LNG conversion and hydrogen yield showed volcano-shaped curves with respect to lanthanum content. Average nickel diameter of (40-x)NixLa catalysts was well correlated with LNG conversion and hydrogen yield over the catalysts. Among the catalysts tested, 36Ni4La (36 wt% Ni and 4 wt% La) catalyst with the smallest average nickel diameter exhibited the best catalytic performance and the strongest resistance toward carbon deposition in the steam reforming of LNG.

Yongju Bang; Jeong Gil Seo; In Kyu Song

2011-01-01T23:59:59.000Z

252

AL  

E-Print Network (OSTI)

AL. EMERGENCY PREPAREDNESS SYLLABUS ATTACHMENT. EMERGENCY NOTIFICATION PROCEDURES are based on a simple concept - if you hear a.

253

Precipitation in 9Ni-12Cr-2Cu maraging steels  

SciTech Connect

Two maraging steels with the compositions 9Ni-12Cr-2Cu-4Mo (wt%) and 9Ni-12Cr-2Cu and with small additions of Al and Ti were investigated using atom probe field ion microscopy. Tomographic atom probe investigations were performed to clarify the spatial distribution of elements in and close to the precipitates. Materials heat treated at 475 C for 5, 25 min, 1, 2, 4 and 400 h were analyzed. Precipitates in the Mo-rich material were observed already after 5 min of aging, while in the material without MO, precipitation started later. In both materials precipitation begins with the formation of Cu-rich particles which work as nucleation sites for a Ni-rich phase of type Ni{sub 3}(Ti,Al). A Mo-rich phase was detected in the Mo-rich steel after 2 h of aging. The distribution of alloying elements in the precipitates, their role in the precipitation process, and the mechanism of hardening in the two materials are discussed.

Stiller, K.; Haettestrand, M. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Physics] [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Physics; Danoix, F. [Univ. de Rouen, Mont Saint Aignan (France). Lab. de Microscopie Ionique] [Univ. de Rouen, Mont Saint Aignan (France). Lab. de Microscopie Ionique

1998-11-02T23:59:59.000Z

254

Solvothermal synthesis of NiAl double hydroxide microspheres on a nickel foam-graphene as an electrode material for pseudo-capacitors  

SciTech Connect

In this paper, we demonstrate excellent pseudo-capacitance behavior of nickel-aluminum double hydroxide microspheres (NiAl DHM) synthesized by a facile solvothermal technique using tertbutanol as a structure-directing agent on nickel foam-graphene (NF-G) current collector as compared to use of nickel foam current collector alone. The structure and surface morphology were studied by X-ray diffraction analysis, Raman spectroscopy and scanning and transmission electron microscopies respectively. NF-G current collector was fabricated by chemical vapor deposition followed by an ex situ coating method of NiAl DHM active material which forms a composite electrode. The pseudocapacitive performance of the composite electrode was investigated by cyclic voltammetry, constant charge–discharge and electrochemical impedance spectroscopy measurements. The composite electrode with the NF-G current collector exhibits an enhanced electrochemical performance due to the presence of the conductive graphene layer on the nickel foam and gives a specific capacitance of 1252 F g{sup ?1} at a current density of 1 A g{sup ?1} and a capacitive retention of about 97% after 1000 charge–discharge cycles. This shows that these composites are promising electrode materials for energy storage devices.

Momodu, Damilola; Bello, Abdulhakeem; Dangbegnon, Julien; Barzeger, Farshad; Taghizadeh, Fatimeh; Fabiane, Mopeli; Manyala, Ncholu, E-mail: ncholu.manyala@up.ac.za [Department of Physics, Institute of Applied Materials, SARChI Chair in Carbon Technology and Materials, University of Pretoria, Pretoria 0028, South Africa. (South Africa); Johnson, A. T. Charlie [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)

2014-09-15T23:59:59.000Z

255

Quantum oscillations and subband properties of the two-dimensional electron gas at the LaAlO{sub 3}/SrTiO{sub 3} interface  

SciTech Connect

We have performed high field magnetotransport measurements to investigate the interface electron gas in a high mobility SrTiO{sub 3}/SrCuO{sub 2}/LaAlO{sub 3}/SrTiO{sub 3} heterostructure. Shubnikov-de Haas oscillations reveal several 2D conduction subbands with carrier effective masses of 0.9m{sub e} and 2m{sub e}, quantum mobilities of order 2000 cm{sup 2}/V s, and band edges only a few millielectronvolts below the Fermi energy. Measurements in tilted magnetic fields confirm the 2D character of the electron gas, and show evidence of inter-subband scattering.

McCollam, A., E-mail: A.McCollam@science.ru.nl; Guduru, V. K.; Zeitler, U.; Maan, J. C. [High Field Magnet Laboratory and Institute for Molecules and Materials, Radboud University Nijmegen, 6525 ED Nijmegen (Netherlands); Wenderich, S.; Kruize, M. K.; Molegraaf, H. J. A.; Huijben, M.; Koster, G.; Blank, D. H. A.; Rijnders, G.; Brinkman, A.; Hilgenkamp, H. [Faculty of Science and Technology and MESA Institute for Nanotechnology, University of Twente, 7500 AE Enschede (Netherlands)

2014-02-01T23:59:59.000Z

256

E-Print Network 3.0 - akot ti alloy Sample Search Results  

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

666670 Phase transformation and precipitation in aged TiNiHf Summary: in aged Ti-Ni-Hf high-temperature shape memory alloys X.L. Meng, W. Cai, Y.F. Zheng, L.C. Zhao...

257

Isothermal oxidation behavior of electrospark deposited MCrAlX-type coatings on a Ni-based superalloy  

Science Journals Connector (OSTI)

A MCrAlX-type coating has been prepared by electrospark deposition (ESD) and its isothermal oxidation behavior studied. The results indicate that deposition rate and surface roughness of the coatings increase with increasing spark pulse energy. A splattered porous morphology was observed in the surface layer, and underneath this, a uniform superfine columnar ? phase structure with a column width of about 0.6 ?m. When exposed at 1000 °C, ?-Al2O3 formed rapidly in the early oxidation stage. After 100 h oxidation, a large amount of ?-Al2O3 was still present, and a dense and adherent, thin ?-Al2O3 scale had formed beneath it.

Yu-jiang Xie; Mao-cai Wang

2009-01-01T23:59:59.000Z

258

Excellent Passivation and Low Reflectivity Al2O3/TiO2 Bilayer Coatings for n-Wafer Silicon Solar Cells: Preprint  

SciTech Connect

A bilayer coating of Al2O3 and TiO2 is used to simultaneously achieve excellent passivation and low reflectivity on p-type silicon. This coating is targeted for achieving high efficiency n-wafer Si solar cells, where both passivation and anti-reflection (AR) are needed at the front-side p-type emitter. It could also be valuable for front-side passivation and AR of rear-emitter and interdigitated back contact p-wafer cells. We achieve high minority carrier lifetimes {approx}1 ms, as well as a nearly 2% decrease in absolute reflectivity, as compared to a standard silicon nitride AR coating.

Lee, B. G.; Skarp, J.; Malinen, V.; Li, S.; Choi, S.; Branz, H. M.

2012-06-01T23:59:59.000Z

259

Elevated-Temperature Corrosion of CoCrCuFeNiAl0.5Bx High-Entropy Alloys in Simulated Syngas Containing H2S  

SciTech Connect

High-entropy alloys are formed by synthesizing five or more principal elements in equimolar or near equimolar concentrations. Microstructure of the CoCrCuFeNiAl{sub 0.5}B{sub x} (x = 0, 0.2, 0.6, 1) high-entropy alloys under investigation is composed of a mixture of disordered bcc and fcc phases and borides. These alloys were tested gravimetrically for their corrosion resistance in simulated syngas containing 0, 0.01, 0.1, and 1 % H{sub 2}S at 500 °C. The exposed coupons were characterized using XRD and SEM. No significant corrosion was detected at 500 °C in syngas containing 0 and 0.01 % H{sub 2}S while significant corrosion was observed in syngas containing 0.1 and 1 % H{sub 2}S. Cu{sub 1.96}S was the primary sulfide in the external corrosion scale on the low-boron high-entropy alloys, whereas FeCo{sub 4}Ni{sub 4}S{sub 8} on the high-boron high-entropy alloys. Multi-phase Cu-rich regions in the low-B high-entropy alloys were vulnerable to corrosive attack.

Dogan, Omer N.; Nielsen, Benjamin C.; Hawk, Jeffrey A.

2013-08-01T23:59:59.000Z

260

Characteristics of a commercially aged Ni-Mo/Al2O3 hydrotreating catalyst: component distribution, nature of coke and effects of regeneration  

SciTech Connect

Information concerning the morphology and behavior of active components on commercially aged catalyst, the effects of regeneration conditions on activity, and insights into the nature of coke and contaminant metal deposits could lead to improved catalysts and operating conditions , yielding significant economic returns. Spent Ni-Mo/Al2O3 hydrotreating catalyst from a commercial hydrotreater was examined using TGA, SEM, STEM, XPS, and a microreactor. Information concerning intraparticle distributions of active components, characteristics of the coke and metal deposits, and catalytic activity for fresh, spent and regenerated catalyst was used to draw general conclusions concerning hydrotreating catalyst deactivation. It was found that catalytic activity was reduced and the nature of the hydrogenation function was altered due to bulk migration and agglomeration of molybdenum. This process was found to be accelerated by high-temperature regeneration. Results also indicated that iron deposits might catalyze formation of coke. Tentative generalizations and suggestions on improved reactor operation are presented.

Bogdanor, J.M.

1984-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ni ti al" from the National Library of EnergyBeta (NLEBeta).
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261

The role of CeO2–ZrO2 distribution on the Ni/MgAl2O4 catalyst during the combined steam and CO2 reforming of methane  

Science Journals Connector (OSTI)

The effect of the distribution of CeO2–ZrO2 on Ni/MgAl2O4 catalyst on the catalytic performance during the combined steam and carbon dioxide reforming of CH4 (CSCR) was investigated on two different catalysts pre...

Jong Wook Bae; A Rong Kim; Seung-Chan Baek…

2011-12-01T23:59:59.000Z

262

Effect of Additives La2O3 AND CeO2 on the Activity and Selectivity of Ni-Al2O3/Cordierite Catalysts in Steam Reforming of Methane  

Science Journals Connector (OSTI)

The introduction of rare-earth elements (CeO2 and La2O3) into Ni-Al2O3.../cordierite catalysts permits a decrease in the water to methane ratio in the reaction mixture for the steam reforming of methane. The carb...

Ie. V. Gubareni; Ya. P. Kurilets; S. O. Soloviev

2014-12-01T23:59:59.000Z

263

Studies on the Stability of a La0.8Pr0.2NiAl11O19 Catalyst for Syngas Production by CO2 Reforming of Methane  

Science Journals Connector (OSTI)

CO2 reforming of CH4 was studied over a magnetoplumbite-type hexaaluminate La0.8Pr0.2NiAl11O19 catalyst, which showed very high activity for over 300 h without deactivation at 1023 K. This catalyst showed good re...

Yan Liu; Tiexin Cheng; Dongmei Li; Pengbo Jiang; Junxia Wang…

2003-01-01T23:59:59.000Z

264

Nature of carbon in Ni/. cap alpha. -Al/sub 2/O/sub 3/ catalyst deactivated by the methane-steam reforming reaction  

SciTech Connect

The mechanism of carbon formation on Ni surfaces has been studied extensively because of its importance both for coke formation on the Ni alloy reactor walls in steam cracking (pyrolysis) of naphtha or paraffinic gases in the petrochemical industry, and for catalyst deactivation in processes using supported Ni catalysts at high temperatures. Characterization of the carbon on Ni catalysts is desirable. In particular, the question whether the carbon is found only on the surface of Ni, or whether it also diffuses or dissolves in Ni, needs to be answered. Information on this is sought here from temperature programmed combustion of the carbon on/in Ni and from x-ray photoelectron spectroscopy (XPS). The very slow combustion of the C in the catalyst and an XPS study of the depth composition profile of the catalyst indicate that the C has diffused or dissolved into the bulk of Ni and a part of it is in a carbidic form.

De DeRen, J. (Laboratorium voor Petrochemische Techniek, Gent, Belgium); Menon, P.G.; Froment, G.F.; Haemers, G.

1981-07-01T23:59:59.000Z

265

Experimental investigations and three-dimensional transmission line matrix simulation of Ca 5 ? x A x B 2 Ti O 12 ( A = Mg , Zn, Ni, and Co; B = Nb and Ta) ceramic resonators  

Science Journals Connector (OSTI)

Temperature-stable low-loss Ca 5 ? x A x B 2 Ti O 12 ( A = Mg Zn Ni and Co; B = Nb and Ta)dielectrics suitable for microwave telecommunication applications were prepared by the conventional solid-state ceramic route. Investigations were made on the structure and microstructure of the ceramics employing x-ray and scanning electron microscopic techniques. The dielectric properties were measured in the 3.5 – 7 GHz frequency range. The time domain simulation of electromagnetic wave interaction with dielectric materials using three-dimensional transmission line matrix modeling methods is presented. Excellent agreement between experimental and simulated values of microwavedielectric properties was observed. The materials are potential candidates for applications in filters oscillators and high efficiency low-loss dielectric antennas working especially at millimeter wave region.

Pazhoor Varghese Bijumon; Mailadil Thomas Sebastian; Pezholil Mohanan

2005-01-01T23:59:59.000Z

266

Effects of Reduction Temperature and Metal-Support Interactions on the Catalytic Activity of Pt/g-Al2O3 and Pt/TiO2 for the Oxidation of CO in the Presence and Absence of H2.  

SciTech Connect

TiO2- and -Al2O3-supported Pt catalysts were characterized by HRTEM, XPS, EXAFS, and in situ FTIR spectroscopy after activation at various conditions, and their catalytic properties were examined for the oxidation of CO in the absence and presence of H2 (PROX). When {gamma}-Al{sub 2}O{sub 3} was used as the support, the catalytic, electronic, and structural properties of the Pt particles formed were not affected substantially by the pretreatment conditions. In contrast, the surface properties and catalytic activity of Pt/TiO2 were strongly influenced by the pretreatment conditions. In this case, an increase in the reduction temperature led to higher electron density on Pt, altering its chemisorptive properties, weakening the Pt-CO bonds, and increasing its activity for the oxidation of CO. The in situ FTIR data suggest that both the terminal and bridging CO species adsorbed on fully reduced Pt are active for this reaction. The high activity of Pt/TiO2 for the oxidation of CO can also be attributed to the ability of TiO2 to provide or stabilize highly reactive oxygen species at the metal-support interface. However, such species appear to be more reactive toward H{sub 2} than CO. Consequently, Pt/TiO{sub 2} shows substantially lower selectivities toward CO oxidation under PROX conditions than Pt/{gamma}-Al{sub 2}O{sub 3}.

Alexeev,O.; Chin, S.; Engelhard, M.; Ortiz-Soto, L.; Amiridis, M.

2005-01-01T23:59:59.000Z

267

Role of oxygen vacancies in magnetic properties of LaAlO{sub 3}/SrTiO{sub 3} interface  

SciTech Connect

The interface of two band-insulators SrTiO{sub 3} and LaAlO{sub 3} exhibits a highly conducting two-dimensional electron gas which shows low-temperature superconductivity, ferromagnetism and many other novel properties. Several studies reveal that the oxygen vacancies at the interface have strong influence on the electronic and magnetic properties of the interface electrons. Here, we develop an insight into the effects of oxygen vacancies on the magnetic properties of the system; the oxygen vacancies help in establishing ferromagnetism which competes with superconductivity at low temperatures. Simulated Monte-Carlo annealing suggests an ordering of the oxygen vacant sites and sheds light on the experimental observation of the quenching of magnetic moment on annealing. A possible explanation for the coexistence of superconductivity and ferromagnetism is also discussed.

Mohanta, N., E-mail: nmohanta@phy.iitkgp.ernet.in [Department of Physics and Meteorology, Indian Institute of Technology Kharagpur, West Bengal-721302 (India); Taraphder, A. [Department of Physics and Meteorology, Indian Institute of Technology Kharagpur, West Bengal-721302, India and Centre for Theoretical Studies, Indian Institute of Technology Kharagpur, West Bengal-721302 (India)

2014-04-24T23:59:59.000Z

268

Structure and Properties of Composite Electrospark, Laser, and Magnetron Deposited AlN ? TiB2 Coatings  

Science Journals Connector (OSTI)

A comparative investigation of the coatings produced by electrospark alloying, laser gas-powder deposition, and magnetron sputtering using composite AlN ?...2...material was carried out. It is shown that the pres...

Irina A. Podchernyaeva

2001-09-01T23:59:59.000Z

269

Evaluation of Zr(Ni, Mn){sub 2} Laves phase alloys as negative active material for Ni-MH electric vehicle batteries  

SciTech Connect

Laves phase alloys of compositions (Zr, Ti)(Ni, Mn, M){sub x} where M = Cr, V, Co, Al, and 1.9 < x < 2.1 with hexagonal C14 or cubic C15 structure have been studied in order to select the most suitable AB{sub 2} alloys as an active material for nickel-metal hydride (Ni-MH) batteries. With the selected alloy, feasibility of MH negative electrodes using industrial technology and containing more than 97% of the alloy powder has been demonstrated. 22 Ah Ni-MH batteries for electric vehicle application have been assembled, and 600 cycles have been achieved at steady C/3 charge and discharge rates and 80% depth of discharge.

Knosp, B. [Alcatel Alsthom Recherche, Marcoussis (France); Jordy, C.; Blanchard, P. [SAFT Research Dept., Marcoussis (France); Berlureau, T. [SAFT Advanced and Industrial Battery Div., Bordeaux (France)

1998-05-01T23:59:59.000Z

270

Scaffolds of magnetically active 3d metals in the valence electron controlled borides Ti{sub 9?x}M{sub 2+x}Ru{sub 18}B{sub 8} (M=Cr–Ni; x=0.5–1): Structutral, electronic and magnetic properties  

SciTech Connect

Polycrystalline samples of the boride series Ti{sub 9?x}M{sub 2+x}Ru{sub 18}B{sub 8} (M=Cr, Co, Mn, Ni) including single crystals of Ti{sub 8}Co{sub 3}Ru{sub 18}B{sub 8} have been prepared by arc-melting the elements. The phases were characterized by powder X-ray diffraction (Rietveld refinement), single-crystal X-ray diffraction (for M=Co), and energy-dispersive X-ray (EDX) analysis. They are substitutional variants of the Zn{sub 11}Rh{sub 18}B{sub 8} structure type, space group P4/mbm (No. 127) and contain a “scaffold” structural unit (M-ladders interacting with M/Ti-chains) as well as isolated M/Ti-chains. According to DFT calculations, the Ru–X (X=B, Ti, Ti/M) bonding interactions are nearly constant throughout the series and responsible for the structural stability of these phases, whereas the M–M and Ru–M interactions vary significantly with varying valence electron count. Furthermore, density of states (DOS) analyses predict the phases with M=Mn and Ni to develop a total magnetic moment but not the M=Co phase. Susceptibility measurements confirm the Co phase to be paramagnetic and the Mn Phase orders ferrimagnetically below 120 K and thus develops a magnetic moment, as predicted. - Graphical abstract: The crystal structures of the new phases (M=Cr, Mn, Co, Ni) are confirmed by Rietveld refinement of powder diffraction data and single crystal X-ray diffraction (for M=Co) to contain beside the M-ladder also M/Ti-chains. Similar to the series Ti{sub 9}M{sub 2}Ru{sub 18}B{sub 8}, the crystal structure of the new phases are mainly stabilized by the heteroatomic Ru–B and Ru–Ti bonds that remain nearly constant throughout the series, whereas the M-containing bonds vary significantly with varying valence electron count. An experimental finding confirmed and even extended by COHP bonding analyses. In addition, the DOS analyses of the M-elements reveal the development of magnetic moments for the M=Mn, Ni cases but not for M=Co. Indeed, Ti{sub 8}Co{sub 3}Ru{sub 18}B{sub 8} was found experimentally to be a paramagnet and ferrimagnetic ordering below 120 K is found for M=Mn. Highlights: • Synthesis of the valence electron controlled borides Ti{sub 9?x}M{sub 2+x}Ru{sub 18}B{sub 8} (M=Cr–Ni). • Prediction of magnetic properties of Ti{sub 9?x}M{sub 2+x}Ru{sub 18}B{sub 8}. • Ferrimagnetic ordering found in Ti{sub 8}M{sub 3}Ru{sub 18}B{sub 8}. • Chemical bonding studied by density functional theory.

Goerens, Christian [Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, D-52056 Aachen (Germany); Brgoch, Jakoah [Department of Chemistry, Iowa State University, Ames, IA 50011 (United States); Miller, Gordon J., E-mail: gmiller@iastate.edu [Department of Chemistry, Iowa State University, Ames, IA 50011 (United States); Fokwa, Boniface P.T., E-mail: boniface.fokwa@ac.rwth-aachen.de [Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, D-52056 Aachen (Germany)

2013-08-15T23:59:59.000Z

271

Effects of testing and storage environments on mechanical properties of Ni-plated and bare U-3/4 wt% Ti  

SciTech Connect

It was found that storage environments with an adequate supply of oxygen can effectively minimize moisture corrosion of bare U-3/4 Ti. In particular, 0.75 cm/sup 3/ of dry air is calculated to protect 1 cm/sup 2/ of U-3/4 Ti for 20 years storage at room temperature. Consideration of the geometric details of U-3/4 Ti alloy specimens and the free volumes of air (and hence O/sub 2/) available can satisfactorily explain discrepancies in corrosion behavior between recent tests and previously reported data. The storage environment at 70/sup 0/C produces a minor strength increase in bare samples with increasing time. Decreases in ductility are observed for testing conditions of low temperature, low strain rate, and/or high humidity. Surface cracks occur under the same conditions conducive to corrosion, i.e., moderate temperatures, low strain rates, and high humidity. Significant increases in strength result under low-temperature and high-strain-rate conditions of tensile testing. Residual chloride contamination may be responsible for the occasional and otherwise unexplained large scatter in ductility for nominally similar specimens and test conditions. Nickel plating is observed to cause a statistically significant decrease in tensile strength, but no effect on the yield strength or ductility was observed and the presence of high explosive during the aging of tensile bars was observed to have no effect on mechanical properties.

Zehr, S.W.; Johnson, H.R.; Smugeresky, J.E.; Pashman, K.A.; Nagelberg, A.S.

1980-01-01T23:59:59.000Z

272

SCC of austenitic stainless steel, Ni-21Cr-13.5Mo alloy, and 0.3Mo-0.8Ni-Ti in 350 C synthetic, NO{sub 2}2-NO{sub 3}-OH tank waste  

SciTech Connect

A necessary step in preparation of high-level radioactive tank waste for sate disposal is removal of non radioactive organic and inorganic components from washed waste. The oxidizing and alkaline nature of most wastes allows the removal of the organic components as water vapor, carbon dioxide, and ammonia gas merely by heating the wastes to no more than 350 C. Type 3 16L stainless steel (UNS S3 1603) a 21Cr-13.5Mo-Ni alloy (UNS N06022), and 0.8Ni-0.3Mo-Ti alloy (UNS R53400) were candidate materials for reactors in which the oxidation could be performed. Slow-strain-rate tests were performed on these three materials at a strain rate of 10{sup {minus}6}sec{sup {minus}1} in a diluted waste type solution containing 4.1% NO{sub 2}, 3.7% NO{sub 3}, 1% OH, and 0.22% TIC. All three materials showed intergranular stress corrosion cracking with substantial losses in ductility and strength.

Pednekar, S.P. [Army Research Lab., Aberdeen Proving Ground, MD (United States)

1998-12-31T23:59:59.000Z

273

Syngas production via dry reforming of CH4 over Co- and Cu-promoted Ni/Al2O3–ZrO2 nanocatalysts synthesized via sequential impregnation and sol–gel methods  

Science Journals Connector (OSTI)

Abstract In this study, the effect of synthesis method (impregnation and so-gel) as well as Co and Cu addition on the catalytic and physicochemical properties of Ni/Al2O3–ZrO2 nanocatalyst was evaluated in dry reforming of methane. The XRD, FESEM, PSD, BET and FTIR analysis were used to characterize the nanocatalysts. Highly dispersed Ni and Zr species and no spinel production in the sol–gel synthesized samples were confirmed by XRD results. The FESEM images showed small and uniform nanoparticles in the sol–gel synthesized catalyst. Also, after Cu added to Ni/Al2O3–ZrO2, the particles were more compact than others. Moreover, the promoters addition especially Co to Ni/Al2O3–ZrO2 nanocatalyst improved the particles size uniformity. Particle size distribution of sol–gel synthesized Ni–Co/Al2O3–ZrO2 nanocatalyst represented that the majority of the particles (nearly 95%) lies between 10 and 40 nm with an average size of 27.4 nm. BET analysis showed higher surface area in the sol–gel samples, especially when it was coupled with Co and Cu addition. The results indicated the remarkable synergetic effect of sol–gel method and Co addition on the surface morphology and elemental dispersion. Activity of nanocatalysts were evaluated as a function of temperature from 550 to 850 °C at GHSV = 24 l/g h, P = 1 atm and CH4/CO2 = 1. The sol–gel synthesized nanocatalyst showed better catalytic performance. Moreover, it was observed that, Cu and Co addition improved feed conversion, products yield and better syngas ratio. The comparison between promoters revealed that activity of Co was better than Cu. During the 1440 min time on stream test at 850 °C, the sol–gel synthesized Ni–Co/Al2O3–ZrO2 nanocatalyst exhibited the best activity compared to the other samples and produced syngas with approximately stoichiometry ratio.

Mahdi Sharifi; Mohammad Haghighi; Farhad Rahmani; Samira Karimipour

2014-01-01T23:59:59.000Z

274

CoNiGa High Temperature Shape Memory Alloys  

E-Print Network (OSTI)

commercially successful SMAs such as NiTi and Cu-based alloys. In recent years, the CoNiGa system has emerged as a new ferromagnetic shape memory alloy with some compositions exhibiting high martensitic transformation temperatures which makes CoNiGa a potential...

Dogan, Ebubekir

2011-10-21T23:59:59.000Z

275

Effect of the strain-induced melt activation (SIMA) process on the tensile properties of a new developed super high strength aluminum alloy modified by Al-5Ti-1B grain refiner  

SciTech Connect

In this study, the effect of Al-5Ti-1B grain refiners and modified strain-induced melt activation process on an Al-Zn-Mg-Cu alloy was studied. The optimum level of Ti was found to be 0.1 wt.%. The specimens subjected to deformation ratio of 40% (at 300 Degree-Sign C) and various heat treatment times (10-40 min) and temperature (550-600 Degree-Sign C) regimes were characterized in this study. Reheating condition to obtain a fine globular microstructure was optimized. Microstructural examinations were conducted by optical and scanning electron microscopy coupled with an energy dispersive spectrometry. The optimum temperature and time in strain-induced melt activation process are 575 Degree-Sign C and 20 min, respectively. T6 heat treatment including quenching to room temperature and aging at 120 Degree-Sign C for 24 h was employed to reach to the maximum strength. Significant improvements in mechanical properties were obtained with the addition of grain refiner combined with T6 heat treatment. After the T6 heat treatment, the average tensile strength increased from 283 MPa to 587 and 332 MPa to 617 for samples refined with 2 wt.% Al-5Ti-1B before and after strain-induced melt activation process and extrusion process, respectively. Ultimate strength of Ti-refined specimens without SIMA process has a lower value than globular microstructure specimens after SIMA and extrusion process. - Highlights: Black-Right-Pointing-Pointer The effect of Al-5Ti-1B on the aluminum alloy produced by SIMA process was studied. Black-Right-Pointing-Pointer Al-5Ti-1B is an effective in reducing the grain and reagent fine microstructure. Black-Right-Pointing-Pointer Reheating condition to obtain a fine globular microstructure was optimized. Black-Right-Pointing-Pointer The optimum temperature and time in SIMA process are 575 Degree-Sign C and 20 min respectively. Black-Right-Pointing-Pointer UTS of globular structure specimens have a more value than Ti-refined specimens.

Haghparast, Amin [School of Mechanical Engineering, College of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of)] [School of Mechanical Engineering, College of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Nourimotlagh, Masoud [Young Researchers Club, Dareshahr Branch, Islamic Azad university (Iran, Islamic Republic of)] [Young Researchers Club, Dareshahr Branch, Islamic Azad university (Iran, Islamic Republic of); Alipour, Mohammad, E-mail: Alipourmo@ut.ac.ir [School of Metallurgy and Materials Engineering, University of Tehran, Tehran (Iran, Islamic Republic of)] [School of Metallurgy and Materials Engineering, University of Tehran, Tehran (Iran, Islamic Republic of)

2012-09-15T23:59:59.000Z

276

Crystal structure, magnetism and transport properties of Ce{sub 3}Ni{sub 25.75}Ru{sub 3.16}Al{sub 4.1}B{sub 10}  

SciTech Connect

Single crystals of Ce{sub 3}Ni{sub 25.75}Ru{sub 3.16}Al{sub 4.1}B{sub 10} were obtained from a process in which a polycrystalline sample of CeRu{sub 2}Al{sub 2}B was annealed in an excess of a Ni–In flux. The initial phase, CeRu{sub 2}Al{sub 2}B, does not recrystallize, instead, crystals of a new phase, Ce{sub 3}Ni{sub 25.75}Ru{sub 3.16}Al{sub 4.1}B{sub 10}, could be isolated once the flux was removed. The title compound crystallizes in the tetragonal space group P4/nmm (No. 129) with a=1139.02(8), c=801.68(6) pm (c/a=0.70) in the Nd{sub 3}Ni{sub 29}Si{sub 4}B{sub 10} structure type. Electrical resistivity measurements reveal metallic behavior with a minimum of 700 µ? cm and a small residual resistivity ratio of RRR=1.4 indicating a large amount of disorder scattering. The cerium atoms are either in the 4+ or an intermediate valence state with a valence fluctuation temperature far above room temperature. - Graphical abstract: Single crystals of Ce{sub 3}Ni{sub 25.75}Ru{sub 3.16}A{sub l4.1}B{sub 10} were obtained using a process in which a polycrystalline sample of CeRu{sub 2}Al{sub 2}B was annealed in an excess of a Ni–In flux. Electrical resistivity measurements reveal metallic behavior with a minimum of 700 ?? cm and a small residual resistivity ratio of RRR=1.4 indicating a large amount of disorder scattering. The cerium atoms are either in the 4+ or an intermediate valence state with a valence fluctuation temperature far above room temperature. Display Omitted - Highlights: • Flux synthesis of high quality single crystals of Ce{sub 3}Ni{sub 25.75}Ru{sub 3.16}Al{sub 4.1}B{sub 10} is presented along with the crystal structure, magnetic and transport properties. • The compound is isostructural to Nd{sub 3}Ni{sub 29}Si{sub 4}B{sub 10} but is first of this structure type showing mixed occupancies of d-elements. • This is an intermetallic phase with Ce in either the 4+ or an intermediate valence state. • The fact that this structure with mixed occupied transition metal sites exists suggests that more compounds of this type should be accessible and the physical properties tuned.

Janka, Oliver [Department of Chemistry, University of California, One Shields Ave, Davis, CA 95616 (United States); Baumbach, Ryan E.; Thompson, Joe D. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Bauer, Eric D., E-mail: edbauer@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Kauzlarich, Susan M., E-mail: smkauzlarich@ucdavis.edu [Department of Chemistry, University of California, One Shields Ave, Davis, CA 95616 (United States)

2013-09-15T23:59:59.000Z

277

Tensile properties and strain rate sensitivity of Ti-47Al-2Cr-0.2Si sheet material with different microstructures  

SciTech Connect

New materials based on gamma titanium aluminides (gamma alloys) have emerged as potential candidates for high temperature applications such as aerospace structural components (e.g., airframes, turbine components, thermal protection systems) and automotive parts (e.g., exhaust valves, turbocharger rotors). Because of their low density, high Young`s modulus, high-temperature strength retention, good oxidation and burn resistance, the so-called second generation gamma alloys are able to exceed the application temperature of advanced titanium alloys and also to replace nickel- and iron-based superalloys up to 800C. However, poor formability and low room temperature (RT) ductility resulting in low fracture toughness have limited possible applications. The present paper deals with the dependence of tensile properties of Ti-47Al-2Cr-0.2Si (composition in atomic-%) sheet material on microstructure and test conditions. Four different microstructures, i.e., fine-grained primary annealed (PA), near gamma (NG), duplex (DU) as well as coarse-grained fully lamellar (FL) have been investigated with emphasis on the influence of grain size, phase distribution, and strain rate on tensile properties at 700 C. Fractography was conducted by scanning electron microscopy (SEM) to examine the influence of temperature on the fracture behavior and to determine the onset of dynamic recrystallization effects.

Clemens, H. [Plansee AG, Reutte (Austria)] [Plansee AG, Reutte (Austria); Glatz, W. [Montanuniversitaet, Leoben (Austria). Inst. fuer Metallkunde und Werkstoffpruefung] [Montanuniversitaet, Leoben (Austria). Inst. fuer Metallkunde und Werkstoffpruefung; Appel, F. [GKSS Research Centre, Geesthacht (Germany). Inst. for Materials Research] [GKSS Research Centre, Geesthacht (Germany). Inst. for Materials Research

1996-08-01T23:59:59.000Z

278

FTIR study of hydrogen and carbon monoxide adsorption on Pt/TiO{sub 2}, Pt/ZrO{sub 2}, and Pt/Al{sub 2}O{sub 3}  

SciTech Connect

The Pt/TiO{sub 2}, Pt/ZrO{sub 2}, and Pt/Al{sub 2}O{sub 3} catalysts submitted to low-temperature reduction (LTR,200 C) and high-temperature reduction (HTR, 500 C) and exposed to hydrogen and carbon monoxide at room temperature were studied by infrared spectroscopy. There is a strong loss of transmission in the entire infrared spectra on Pt/TiO{sub 2} after its exposure to hydrogen, which is related to the reducibility of the support. A typical SMSI behavior (strong metal-support interaction), such as the decrease in carbon monoxide adsorption capacity, was detected on Pt/TiO{sub 2} and Pt/ZrO{sub 2} after exposure to hydrogen, even for the catalysts submitted to LTR treatment. Also a carbonyl band shift to lower wavenumber was observed on LTR-treated Pt/TiO{sub 2}, Pt/ZrO{sub 2}, and Pt/Al{sub 2}O{sub 3} after exposure to hydrogen. The authors interpreted this SMSI behavior as an electronic rather than morphological effect, which was induced by the presence of hydrogen spillover.

Benvenutti, E.V.; Franken, L.; Moro, C.C.; Davanzo, C.U.

1999-11-09T23:59:59.000Z

279

Au/MxOy/TiO2 catalysts for CO oxidation: promotional effect of main-group, transition, and rare-earth metal oxide additives.  

SciTech Connect

Au/TiO2 catalysts are active for CO oxidation, but they suffer from high-temperature sintering of the gold particles, and few attempts have been made to promote or stabilize Au/TiO2. Our recent communication addressed these issues by loading gold onto Al2O3/TiO2 prepared via surface-sol-gel processing of Al(sec-OC4H9)3 on TiO2. In our current full paper, Au/Al2O3/TiO2 catalysts were prepared alternatively by thermal decomposition of Al(NO3)3 on TiO2 followed by loading gold, and the influences of the decomposition temperature and Al2O3 content were systematically surveyed. This facile method was subsequently extended to the preparation of a battery of metal oxide-modified Au/TiO2 catalysts virtually not reported. It was found that Au/TiO2 modified by CaO, NiO, ZnO, Ga2O3, Y2O3, ZrO2, La2O3, Pr2O3, Nd2O3, Sm2O3, Eu2O3, Gd2O3, Dy2O3, Ho2O3, Er2O3, or Yb2O3 could retain significant activity at ambient temperature even after aging in O2-He at 500 C, whereas unmodified Au/TiO2 lost its activity. Moreover, some 200 C-calcined promoted catalysts showed high activity even at about -100 C. The deactivation and regeneration of some of these new catalysts were studied. This work furnished novel catalysts for further fundamental and applied research.

Ma, Zhen [ORNL; Overbury, Steven {Steve} H [ORNL; Dai, Sheng [ORNL

2007-01-01T23:59:59.000Z

280

Effects of Annealing on the Microstructure and Properties of 6FeNiCoCrAlTiSi High-Entropy Alloy Coating Prepared by Laser Cladding  

Science Journals Connector (OSTI)

The content of each constituent element in the newly developed high-entropy alloys is always restricted in equimolar or near-equimolar ratios to avoid the formation of complex brittle phases during the solidifica...

Hui Zhang; Ye Pan; Yizhu He

2011-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "ni ti al" 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

Phase constitution, Mechanical Property and Corrosion Resistance of the Ti-Nb Alloys  

E-Print Network (OSTI)

the Ti-Ni alloy in the dental application. In the non-oral condition, the Ti-52Nb alloy may be preferable, dentistry and interventional radiology because of their superior shape memory effect and superelasticity [1

Zheng, Yufeng

282

Structural Underpinnings of the Enhanced Cycling Stability upon Al-Substitution in LiNi[subscript 0.45]Mn[subscript 0.45]Co[subscript 0.1?y]Al[subscript y]O[subscript 2] Positive Electrode Materials for Li-ion Batteries  

SciTech Connect

Single-phase LiNi{sub 0.45}Mn{sub 0.45}Co{sub 0.1-y}Al{sub y}O{sub 2} layered oxide materials with 0 {<=} y {<=} 0.10 were prepared using the glycine-nitrate combustion method. Al-substitution has a minimal effect on the defect concentration and rate capability of the materials, but raises the operating voltage and reduces the capacity fade of the materials during prolonged cycling compared to the unsubstituted system. In situ X-ray diffraction suggests the presence of Al has a significant structural impact during battery operation. It acts to limit the changes in lattice parameters observed during electrochemical charging and cycling of the materials. High-resolution X-ray diffraction reveals structural distortions in the transition metal layers of as-synthesized powders with high Al-contents, as well as a structural evolution seen in all materials after cycling.

Conry, Thomas E.; Mehta, Apurva; Cabana, Jordi; Doeff, Marca M. (UCB); (SSRL)

2012-10-23T23:59:59.000Z

283

Dielectric spectroscopy of Pb{sub 0.92}La{sub 0.08}Zr{sub 0.52}Ti{sub 0.48}O{sub 3} films on hastelloy substrates with and without LaNiO{sub 3} buffer layers.  

SciTech Connect

Pb{sub 0.92}La{sub 0.08}Zr{sub 0.52}Ti{sub 0.48}O{sub 3} (PLZT) films were deposited by sol-gel synthesis on Hastelloy substrates with and without a LaNiO{sub 3} buffer. The dielectric properties were measured as a function of temperature and frequency to study the cause of dielectric degradation in PLZT films directly on hastelloy substrates. These measurements indicated an increased charge carrier activity in films without a buffer layer. We propose that a region of the film closer to the substrate surface is more oxygen deficient than the bulk and is responsible for the degradation in properties rather than the presence of a low parasitic secondary-phase interfacial layer such as NiO{sub x}.

Narayanan, M.; Ma, B.; Balachandran, U.; Li, W.

2010-01-01T23:59:59.000Z

284

Dielectric spectroscopy of Pb{sub 0.92}La{sub 0.08}Zr{sub 0.52}Ti{sub0.48}O{sub 3} films on hastealloy substrates with and without LaNiO{sub 3} buffer layers.  

SciTech Connect

Pb{sub 0.92}La{sub 0.08}Zr{sub 0.52}Ti{sub 0.48}O{sub 3} (PLZT) films were deposited by sol-gel synthesis on Hastelloy substrates with and without a LaNiO{sub 3} buffer. The dielectric properties were measured as a function of temperature and frequency to study the cause of dielectric degradation in PLZT films directly on hastelloy substrates. These measurements indicated an increased charge carrier activity in films without a buffer layer. We propose that a region of the film closer to the substrate surface is more oxygen deficient than the bulk and is responsible for the degradation in properties rather than the presence of a low parasitic secondary-phase interfacial layer such as NiO{sub x}.

Narayanan, M.; Ma, B.; Balachandran, U.; Li, W. (Energy Systems); ( MSD)

2010-01-01T23:59:59.000Z

285

DC current induced metal-insulator transition in epitaxial Sm{sub 0.6}Nd{sub 0.4}NiO{sub 3}/LaAlO{sub 3} thin film  

SciTech Connect

The metal-insulator transition (MIT) in strong correlated electron materials can be induced by external perturbation in forms of thermal, electrical, optical, or magnetic fields. We report on the DC current induced MIT in epitaxial Sm{sub 0.6}Nd{sub 0.4}NiO{sub 3} (SNNO) thin film deposited by pulsed laser deposition on (001)-LaAlO{sub 3} substrate. It was found that the MIT in SNNO film not only can be triggered by thermal, but also can be induced by DC current. The T{sub MI} of SNNO film decreases from 282 K to 200 K with the DC current density increasing from 0.003 × 10{sup 9} A•m{sup ?2} to 4.9 × 10{sup 9} A•m{sup ?2}. Based on the resistivity curves measured at different temperatures, the MIT phase diagram has been successfully constructed.

Huang, Haoliang [Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China) [Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China); Luo, Zhenlin, E-mail: zlluo@ustc.edu.cn; Yang, Yuanjun; Yang, Mengmeng; Wang, Haibo; Hu, Sixia; Bao, Jun [CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China) [CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China); National Synchrotron Radiation Laboratory and School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026 (China); Yun, Yu; Meng, Dechao; Lu, Yalin [CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China)] [CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China); Gao, Chen, E-mail: cgao@ustc.edu.cn [Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China) [Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China); National Synchrotron Radiation Laboratory and School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026 (China)

2014-05-15T23:59:59.000Z

286

N NE EX XT T G GE EN NE ER RA AT TI IO ON N S SA AF FE EG  

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

NE NE EX XT T G GE EN NE ER RA AT TI IO ON N S SA AF FE EG GU UA AR RD DS S I IN NI IT TI IA AT TI IV VE E ( (N NG GS SI I) ) O OP PP PO OR RT TU UN NI IT TI IE ES S F FO OR R S ST TU UD DE EN NT TS S A AN ND D Y YO OU UN NG G P PR RO OF FE ES SS SI IO ON NA AL LS S I IN NT TE ER RE ES ST TE ED D I IN N S SA AF FE EG GU UA AR RD DS S/ /N NO ON NP PR RO OL LI IF FE ER RA AT TI IO ON N The Next Generation Safeguards Initiative (NGSI) was launched by the National Nuclear Security Administration (NNSA) in FY 2008 to develop the policies, concepts, technologies, expertise, and infrastructure necessary to strengthen and sustain the international safeguards system as it evolves to meet new challenges over the next 25 years. NGSI's Human Capital Development subprogram 1 aims to revitalize and expand the international safeguards human capital base in the United States by attracting, educating, training, and retaining

287

PRODUCTION OF {sup 26}Al, {sup 44}Ti, AND {sup 60}Fe IN CORE-COLLAPSE SUPERNOVAE: SENSITIVITY TO THE RATES OF THE TRIPLE ALPHA AND {sup 12}C({alpha}, {gamma}){sup 16}O REACTIONS  

SciTech Connect

We have studied the sensitivity to variations in the triple alpha and {sup 12}C({alpha}, {gamma}){sup 16}O reaction rates of the production of {sup 26}Al, {sup 44}Ti, and {sup 60}Fe in core-collapse supernovae (SNe). We used the KEPLER code to model the evolution of 15 M {sub sun}, 20 M {sub sun}, and 25 M {sub sun} stars to the onset of core collapse and simulated the ensuing SN explosion using a piston model for the explosion and an explosion energy of 1.2 x 10{sup 51} erg. Calculations were performed for the Anders and Grevesse and Lodders abundances. Over a range of twice the experimental uncertainty, {sigma}, for each helium-burning rate, the production of {sup 26}Al, {sup 60}Fe, and their ratio vary by factors of 5 or more. For some species, similar variations were observed for much smaller rate changes, 0.5{sigma} or less. The production of {sup 44}Ti was less sensitive to changes in the helium-burning rates. Production of all three isotopes depended on the solar abundance set used for the initial stellar composition.

Tur, Clarisse; Austin, Sam M. [National Superconducting Cyclotron Laboratory, Michigan State University, 1 Cyclotron Laboratory, East Lansing, MI 48824-1321 (United States); Heger, Alexander, E-mail: tur@nscl.msu.ed, E-mail: austin@nscl.msu.ed, E-mail: alex@physics.umn.ed [School of Physics and Astronomy, University of Minnesota, Twin Cities, Minneapolis, MN 55455-0149 (United States)

2010-07-20T23:59:59.000Z

288

Phase Relations and Elemental Distribution Among Co-Existing Phases in the Ceramics of the Pseudobinary System CaZrTi{sub 2}O{sub 7}-LnAlO{sub 3} (Ln= Nd, Sm)  

SciTech Connect

In the ceramics in series (1-x) CaZrTi{sub 2}O{sub 7} - x NdAlO{sub 3} and (1-x) CaZrTi{sub 2}O{sub 7} - x SmAlO{sub 3} (x = 0.25, 0.5 and 0.75) produced by cold pressing and sintering at 1400, 1450 and 1500 deg. C zirconolite was found to be a major phase, perovskite was an extra phase and traces of residual baddeleyite occurred. At x = 0.75 the perovskite was major phase and zirconolite and cubic oxide of fianite or tazheranite type were extra phases. Major Nd and Sm host phase at x = 0.25 was found to be zirconolite (about 65% of total Nd{sub 2}O{sub 3} and 74% of total Sm{sub 2}O{sub 3}). With the x value increasing perovskite becomes major host phase for Nd and Sm accumulating of up to about 92% of total Nd and about 72% of total Sm. As follows from SEM/EDS data Nd and Sm contents in the zirconolite may reach {approx}1 formula unit (fu). (authors)

Mikhailenko, Natalia [SIA Radon, Moscow, 119121 (Russian Federation); Stefanovsky, Sergey [Center of Advanced Technologies, SIA Radon, 7th Rostovskii lane 2/14, Moscow, 119121 (Russian Federation); Ochkin, Alexander [D. Mendeleev University of Chemical Technology, Moscow (Russian Federation)

2007-07-01T23:59:59.000Z

289

Reactivity deterioration of NiO/Al{sub 2}O{sub 3} oxygen carrier for chemical looping combustion of coal in a 10 kW{sub th} reactor  

SciTech Connect

A relatively long-term experiment for chemical looping combustion of coal with NiO/Al{sub 2}O{sub 3} oxygen carrier was carried out in a 10 kW{sub th} continuous reactor of interconnected fluidized beds, and 100 h of operation was reached with the same batch of the oxygen carrier. The reactivity deterioration of the oxygen carriers was present during the experimental period. The reactivity deterioration of reacted oxygen carriers at different experimental stages was evaluated using X-ray diffraction (XRD), scanning electron microscope (SEM), and X-ray fluorescence spectrometer. SEM analysis showed no significant change in the morphology of the nickel-based oxygen carrier at the fuel reactor temperature {<=}940 C, but loss of surface area and porosity of reacted oxygen carriers was observed when the fuel reactor temperature exceeded 960 C. The results show that the sintering effect have mainly contributed to the reactivity deterioration of reacted oxygen carriers in the CLC process for coal, while the effects of coal ash and sulfur can be ignored. The oxidization of reduced oxygen carrier with air was an intensive exothermic process, and the high temperature of oxygen carrier particles led to sintering on the surface of oxygen carrier particles in the air reactor. Attention must be paid to control the external circulation of oxygen carrier particles in the interconnected fluidized beds in order to efficiently transport heat from the air reactor to the fuel reactor, and reduce the temperature of oxygen carrier particles in the air reactor. Improvement of reactivity deterioration of reacted oxygen carriers was achieved by the supplement of steam into the fuel reactor. Nevertheless, NiO/Al{sub 2}O{sub 3} is still one of the optimal oxygen carriers for chemical looping combustion of coal if the sintering of oxygen carrier is minimized at the suitable reactor temperature. (author)

Shen, Laihong; Wu, Jiahua; Gao, Zhengping; Xiao, Jun [Thermoenergy Engineering Research Institute, Southeast University, 2 Sipailou, Nanjing 210096 (China)

2009-07-15T23:59:59.000Z

290

Hai un'idea di impresa? La Regione Veneto ti aiuta a realizzarla La Direzione Lavoro della Regione Veneto partecipa al progetto I. E. SMART -Smart Training  

E-Print Network (OSTI)

Veneto partecipa al progetto I. E. SMART - Smart Training Network for Innovation and Entrepreneurship Competition è un concorso di idee che si svolge in più fasi: dal 1° agosto al 30 ottobre 2013 si raccolgono le idee presentate tramite il formulario on line che trovi collegandoti al seguente link: http

Romeo, Alessandro

291

Reduction of NOx emission on NiCrAl-Titanium Oxide coated direct injection diesel engine fuelled with radish (Raphanus sativus) biodiesel  

Science Journals Connector (OSTI)

The main aim of this study is the experimental investigation of single cylinder DI diesel engine with and without coating. Diesel and radish (Raphanus sativus) oil Methyl Ester are used as fuels and the results are compared to find the effect of biodiesel in a thermal barrier coating engine. For this purpose engine cylinder head valves and piston crown are coated with 100??m of nickel-chrome-aluminium bond coat and 450??m of TiO2 by the plasma spray method. Radish oil methyl ester is produced by the transesterification process method. From the experimental investigation slight increase in specific fuel consumption in thermal barrier coating engine is observed when compared with the uncoated engine whereas NOx HC Smoke and CO emissions decreased with coated engine for all test fuels used in the coated engine when compared with that of the uncoated engine.

V. Ravikumar; D. Senthilkumar

2013-01-01T23:59:59.000Z

292

Photosensitivity of the Ni-A state of [NiFe] hydrogenase from Desulfovibrio vulgaris Miyazaki F with visible light  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer Ni-A state of [NiFe] hydrogenase showed light sensitivity. Black-Right-Pointing-Pointer New FT-IR bands were observed with light irradiation of the Ni-A state. Black-Right-Pointing-Pointer EPR g-values of the Ni-A state shifted upon light irradiation. Black-Right-Pointing-Pointer The light-induced state converted back to the Ni-A state under the dark condition. -- Abstract: [NiFe] hydrogenase catalyzes reversible oxidation of molecular hydrogen. Its active site is constructed of a hetero dinuclear Ni-Fe complex, and the oxidation state of the Ni ion changes according to the redox state of the enzyme. We found that the Ni-A state (an inactive unready, oxidized state) of [NiFe] hydrogenase from Desulfovibrio vulgaris Miyazaki F (DvMF) is light sensitive and forms a new state (Ni-AL) with irradiation of visible light. The Fourier transform infrared (FT-IR) bands at 1956, 2084 and 2094 cm{sup -1} of the Ni-A state shifted to 1971, 2086 and 2098 cm{sup -1} in the Ni-AL state. The g-values of g{sub x} = 2.30, g{sub y} = 2.23 and g{sub z} = 2.01 for the signals in the electron paramagnetic resonance (EPR) spectrum of the Ni-A state at room temperature varied for -0.009, +0.012 and +0.010, respectively, upon light irradiation. The light-induced Ni-AL state converted back immediately to the Ni-A state under dark condition at room temperature. These results show that the coordination structure of the Fe site of the Ni-A state of [NiFe] hydrogenase is perturbed significantly by light irradiation with relatively small coordination change at the Ni site.

Osuka, Hisao [Graduate School of Life Science, University of Hyogo, 3-2-1, Koto, Kamigori-cho, Ako-gun, Hyogo 678-1297 (Japan) [Graduate School of Life Science, University of Hyogo, 3-2-1, Koto, Kamigori-cho, Ako-gun, Hyogo 678-1297 (Japan); Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5, Takayama-cho, Ikoma-shi, Nara 630-0192 (Japan); Shomura, Yasuhito; Komori, Hirofumi; Shibata, Naoki [Graduate School of Life Science, University of Hyogo, 3-2-1, Koto, Kamigori-cho, Ako-gun, Hyogo 678-1297 (Japan)] [Graduate School of Life Science, University of Hyogo, 3-2-1, Koto, Kamigori-cho, Ako-gun, Hyogo 678-1297 (Japan); Nagao, Satoshi [Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5, Takayama-cho, Ikoma-shi, Nara 630-0192 (Japan)] [Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5, Takayama-cho, Ikoma-shi, Nara 630-0192 (Japan); Higuchi, Yoshiki, E-mail: hig@sci.u-hyogo.ac.jp [Graduate School of Life Science, University of Hyogo, 3-2-1, Koto, Kamigori-cho, Ako-gun, Hyogo 678-1297 (Japan) [Graduate School of Life Science, University of Hyogo, 3-2-1, Koto, Kamigori-cho, Ako-gun, Hyogo 678-1297 (Japan); CREST, JST, Gobancho, Chiyoda-ku, Tokyo 102-0076 (Japan); Hirota, Shun, E-mail: hirota@ms.naist.jp [Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5, Takayama-cho, Ikoma-shi, Nara 630-0192 (Japan) [Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5, Takayama-cho, Ikoma-shi, Nara 630-0192 (Japan); CREST, JST, Gobancho, Chiyoda-ku, Tokyo 102-0076 (Japan)

2013-01-04T23:59:59.000Z

293

Microstructures and properties of laser-glazed plasma-sprayed ZrO{sub 2}-YO{sub 1.5}/Ni-22Cr-10Al-1Y thermal barrier coatings  

SciTech Connect

Thermal barrier coatings (TBCs) consisting of two layers with various yttria contents (ZrO{sub 2}-YO{sub 1.5}/Ni-22Cr-10Al-1Y) were plasma sprayed, and parts of the various specimens were glazed by using a pulsed CO{sub 2} laser. All the specimens were then subjected to furnace thermal cycling tests at 1,100 C; the effect of laser glazing on the durability and failure mechanism of the TBCs was then evaluated. From these results, two models were developed to show the failure mechanism of as-sprayed and laser-glazed TBCs: model A, which is thermal-stress dominant, and model V, which is oxidation-stress dominant. For top coats containing cubic phase, cubic and monoclinic phases, or tetragonal and a relatively larger amount of monoclinic phases, whose degradation is thermal-stress dominant, laser glazing improved the durability of TBCs by a factor of about 2 to 6. Segmented cracks that occurred during glazing proved beneficial for accommodating thermal stress and raising the tolerance to oxidation, which resulted in a higher durability. Thermal barrier coatings with top coats containing tetragonal phase had the highest durability. Degradation of such TBCs resulted mainly from oxidation of the bond coats. For top coats with a greater amount of monoclinic phase, thermal mismatch stress occurred during cooling and detrimentally affected durability.

Tsai, H.L.; Tsai, P.C. [National Taiwan Inst. of Tech., Taipei (Taiwan, Province of China). Dept. of Mechanical Engineering and Technology

1995-12-01T23:59:59.000Z

294

E-Print Network 3.0 - alloyed mg50 ni50 Sample Search Results  

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

Ti29.2Ni50.8Hf20 ... Source: Zheng, Yufeng - Department of Advanced Materials and Nanotechnology, Peking University Collection: Materials Science ; Biology and Medicine 2 J. PHYS....

295

al embarazo reporte: Topics by E-print Network  

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

of superelastic CuAlNi single crystal shape memory alloy during stress Sun, Qing-Ping 133 Josephson effect and tunneling spectroscopy in NbAl2O3AlMgB2 thin films junctions...

296

Mechanism and kinetics of carbide dissolution in near alpha Ti-5.6Al-4.8Sn-2Zr-1Mo-0.35Si-0.7Nd titanium alloy  

SciTech Connect

The present work evaluates the influence of bulk carbon content and aging temperature on the stability of carbide in near alpha Ti-5.6Al-4.8Sn-2Zr-1Mo-0.35Si-0.7Nd titanium alloy. The carbide particles were formed during heat treatment in the {beta} phase field and preserved by water quenching. Subsequent aging treatments at 750-850 Degree-Sign C caused partial dissolution of these precipitates, as a result of the peritectoid reaction between the {beta} phase and carbide. The models based on interface reaction controlled dissolution, via uniform atomic detachment, dislocation mechanism or vacancy flow, yielded experimental predictions comparable to the observed dissolution kinetics. Furnace cooling after heat treatment in the {beta} phase field dissolved carbide particles completely, and the microstructure changed from acicular-like or block {alpha} to equiaxed {alpha} with increase of carbon content. - Highlights: Black-Right-Pointing-Pointer Carbide dissolution occurs at precipitate/matrix interfaces, forming {beta}-depleted zone. Black-Right-Pointing-Pointer Peritectoid reaction is responsible for drastic reduction of carbide volume fraction. Black-Right-Pointing-Pointer Slower dissolution rate is accounted by dislocation, vacancy flow, and curvature. Black-Right-Pointing-Pointer Lamellar changed to equiaxed {alpha} with increasing carbon from {beta} furnace cooling.

Zhang, S.Z., E-mail: szzhangyt@163.com [School of Environmental and Materials Engineering, Yantai University, 32 Qingquan Road, Yantai 264005 (China); Li, M.M. [School of Environmental and Materials Engineering, Yantai University, 32 Qingquan Road, Yantai 264005 (China); Yang, R. [Titanium Alloy Laboratory, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China)

2011-12-15T23:59:59.000Z

297

Additively manufactured 3D porous Ti-6Al-4V constructs mimic trabecular bone structure and regulate osteoblast proliferation, differentiation and local factor production in a porosity and surface roughness dependent manner  

Science Journals Connector (OSTI)

Additive manufacturing by laser sintering is able to produce high resolution metal constructs for orthopedic and dental implants. In this study, we used a human trabecular bone template to design and manufacture Ti-6Al-4V constructs with varying porosity via laser sintering. Characterization of constructs revealed interconnected porosities ranging from 15–70% with compressive moduli of 2579–3693 MPa. These constructs with macro porosity were further surface-treated to create a desirable multi-scale micro-/nano-roughness, which has been shown to enhance the osseointegration process. Osteoblasts (MG63 cells) exhibited high viability when grown on the constructs. Proliferation (DNA) and alkaline phosphatase specific activity, an early differentiation marker, decreased as porosity increased, while osteocalcin, a late differentiation marker, as well as osteoprotegerin, vascular endothelial growth factor and bone morphogenetic proteins 2 and 4 increased with increasing porosity. Three-dimensional (3D) constructs with the highest porosity and surface modification supported the greatest osteoblast differentiation and local factor production. These results indicate that additively manufactured 3D porous constructs mimicking human trabecular bone and produced with additional surface treatment can be customized for increased osteoblast response. Increased factors for osteoblast maturation and differentiation on high porosity constructs suggest the enhanced performance of these surfaces for increasing osseointegration in vivo.

Alice Cheng; Aiza Humayun; David J Cohen; Barbara D Boyan; Zvi Schwartz

2014-01-01T23:59:59.000Z

298

Structure, magnetic properties and magnetoelastic anisotropy in epitaxial Sr(Ti???Co?)O? films  

E-Print Network (OSTI)

We report the structure, magnetic properties and magnetoelastic anisotropy of epitaxial Sr(Ti???Co?)O? films grown on LaAlO? (001) and SrTiO? (001) substrates by pulsed laser deposition. Room temperature ferromagnetism was ...

Bi, Lei

299

Ti Plasmid  

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

Ti Plasmid Ti Plasmid Name: Dixenia Location: N/A Country: N/A Date: N/A Question: What can you tell me about the Ti Plasmid? Replies: This plasmid is named for a plasmid found in a bacteria called Agrobacter tumefaciens. It causes "plant cancer" or what are known as galls. They are little tumors in which the bacteria can grow and live in the plant. Ti stands for tumor inducing. The bacterium gets into the plant through some kind of wound, ie. a scratch. It injects its plasmid into a plant cell and the plasmid inserts its DNA into the plant's DNA. Then the DNA directs the plant to make a hollow tumor where the bacteria can live. Scientists have taken advantage of this plant's ability to insert foreign DNA into a plant. They take the genes out of the plasmid that cause galls, and insert genes of interest, ie. genes for pest resistance and let the plasmid carry those genes into the plant. The plant will start making the product you want. You may have seen a picture of a tobacco plant glowing because firefly genes for glowing were inserted into the plant. They did this so they could know if the gene had made it into the plant. Once they are sure the gene they want has made it into the plant, they clone the plant cells. By the way, plant tissue culture is a procedure that is very common and has been done for years, this is not the same as cloning animals.

300

Deuterium absorption in Mg70Al30 thin films with bilayer catalysts: A comparative neutron reflectometry study  

Science Journals Connector (OSTI)

We present a neutron reflectometry study of deuterium absorption in thin films of Al-containing Mg alloys capped with a Ta/Pd, Ni/Pd and Ti/Pd-catalyst bilayer. The measurements were performed at room temperature over the 0–1 bar pressure range under quasi-equilibrium conditions. The modeling of the measurements provided a nanoscale representation of the deuterium profile in the layers at different stages of the absorption process. The absorption mechanism observed was found to involve spillover of atomic deuterium from the catalyst layer to the Mg alloy phase, followed by the deuteration of the Mg alloy. Complete deuteration of the Mg alloy occurs in a pressure range between 100 and 500 mbar, dependent on the type of bilayer catalyst. The use of a Ti/Pd bilayer catalyst yielded the best results in terms of both storage density and kinetic properties.

Eric Poirier; Chris T. Harrower; Peter Kalisvaart; Adam Bird; Anke Teichert; Dirk Wallacher; Nico Grimm; Roland Steitz; David Mitlin; Helmut Fritzsche

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ni ti al" 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

Prediction of flow stress in a wide temperature range involving phase transformation for as-cast Ti–6Al–2Zr–1Mo–1V alloy by artificial neural network  

Science Journals Connector (OSTI)

The isothermal compressions of as-cast Ti–6Al–2Zr–1Mo–1V titanium alloy in a wide temperature range of 1073–1323 K and strain rate range of 0.01–10 s?1 with a reduction of 60% were conducted on a Gleeble-1500 thermo-mechanical simulator. The flow stress shows a complex non-linear intrinsic relationship with strain, strain rate and temperature, meanwhile the strain-softening behavior articulates dynamic recrystallization mechanism in ? phase, dynamic recovery mechanism in ? phase and their comprehensive function during phase transformation (? + ?). Based on the experimental data, an artificial neural network (ANN) was trained with standard back-propagation learning algorithm to generalize the complex deformation behavior characteristics. In the present ANN model, strain and temperature were taken as inputs, and flow stress as output. A comparative study has been made on ANN model and improved Arrhenius-type constitutive model, and their predictability has been evaluated in terms of correlation coefficient (R) and average absolute relative error (ARRE). During ?, ? + ? and ? phase regime, R-value and ARRE-value for the improved Arrhenius-type model are 0.9824% and 6.02%, 0.9644% and 21.02%, and 0.9627% and 12.38%, respectively, while the R-value and ARRE-value for the ANN model are 0.9992% and 0.91%, 0.9996% and 1.47%, and 0.9975% and 2.17%, respectively. The predicted strain–stress curves outside of experimental conditions articulate the similar intrinsic relationships with experimental strain–stress curves. The results show that the feed-forward back-propagation ANN model can accurately tracks the experimental data in a wide temperature range and strain rate range associated with interconnecting metallurgical phenomena, and in further it has a good capacity to model complex hot deformation behavior of titanium alloy outside of experimental conditions.

Guo-zheng Quan; Wen-quan Lv; Yuan-ping Mao; Yan-wei Zhang; Jie Zhou

2013-01-01T23:59:59.000Z

302

Dirac cones in artificial structures of 3d transitional-metals doped Mg-Al spinels  

SciTech Connect

Motivated by recent theoretical predications for Dirac cone in two-dimensional (2D) triangular lattice [H. Ishizuka, Phys. Rev. Lett. 109, 237207 (2012)], first-principles studies are performed to predict Dirac cones in artificial structures of 3d transitional-metals (TM?=?Ti, V, Cr, Mn, Fe, Co, Ni, and Cu) doped Mg-Al spinels. In investigated artificial structures, TM dopants substitute specific positions of the B sub-lattice in Mg-Al spinel, and form a quasi-2D triangular lattice in the a-b plane. Calculated results illustrate the existence of the spin-polarized Dirac cones formed in d-wave bands at (around) the K-point in the momentum space. The study provides a promising route for engineering Dirac physics in condensed matters.

Lu, Yuan; Zuo, Xu, E-mail: xzuo@nankai.edu.cn [College of Electronic Information and Optical Engineering, Nankai University, Tianjin 300071 (China); Feng, Min [School of Physics, Nankai University, Tianjin 300071 (China); Shao, Bin [Department of Physics, Tsinghua University, Beijing 100084 (China)

2014-05-07T23:59:59.000Z

303

Growth of Epitaxial gamma-Al2O3 Films on Rigid Single-Crystal Ceramic Substrates and Flexible, Single-Crystal-Like Metallic Substrates by Pulsed Laser Deposition  

SciTech Connect

Epitaxial -Al2O3 thin films were grown on diverse substrates using pulsed laser deposition. The high quality of epitaxial growth and cubic structure of -Al2O3 films was confirmed by x-ray diffraction. SrTiO3 and MgO single crystal substrates were used to optimize the growth conditions for epitaxial -Al2O3 film. Under the optimized conditions, epitaxial -Al2O3 thin films were grown on flexible, single-crystal-like, metallic templates. These included untextured Hastelloy substrates with a biaxially textured MgO layer deposited using ion-beam-assisted-deposition and biaxially textured Ni-W metallic tapes with epitaxially grown and a biaxially textured, MgO buffer layer. These biaxially textured, -Al2O3 films on flexible, single-crystal-like substrates are promising for subsequent epitaxial growth of various complex oxide films used for electrical, magnetic and electronic device applications.

Shin, Junsoo [ORNL; Goyal, Amit [ORNL; Wee, Sung Hun [ORNL

2009-01-01T23:59:59.000Z

304

Salicidation process using NiSi and its device application R. A. Johnson, P. M. Asbeck, and S. S. Lau  

E-Print Network (OSTI)

temperature window. In this article, the formation of nickel mono-silicide NiSi using rapid thermal annealing. In the recent past, there have been concerns related to the in- crease of TiSi2 film resistivity on submicron resistivity C54 phase.5,6 The TiSi2 process- ing temperature window is relatively narrow due to the high

Asbeck, Peter M.

305

Exploration of R2XM2 (R=Sc, Y, Ti, Zr, Hf, rare earth; X=main group element; M=transition metal, Si, Ge): Structural Motifs, the novel Compound Gd2AlGe2 and Analysis of the U3Si2 and Zr3Al2 Structure Types  

SciTech Connect

In the process of exploring and understanding the influence of crystal structure on the system of compounds with the composition Gd{sub 5}(Si{sub x}Ge{sub 1-x}){sub 4} several new compounds were synthesized with different crystal structures, but similar structural features. In Gd{sub 5}(Si{sub x}Ge{sub 1-x}){sub 4}, the main feature of interest is the magnetocaloric effect (MCE), which allows the material to be useful in magnetic refrigeration applications. The MCE is based on the magnetic interactions of the Gd atoms in the crystal structure, which varies with x (the amount of Si in the compound). The crystal structure of Gd{sub 5}(Si{sub x}Ge{sub 1-x}){sub 4} can be thought of as being formed from two 3{sup 2}434 nets of Gd atoms, with additional Gd atoms in the cubic voids and Si/Ge atoms in the trigonal prismatic voids. Attempts were made to substitute nonmagnetic atoms for magnetic Gd using In, Mg and Al. Gd{sub 2}MgGe{sub 2} and Gd{sub 2}InGe{sub 2} both possess the same 3{sup 2}434 nets of Gd atoms as Gd{sub 5}(Si{sub x}Ge{sub 1-x}){sub 4}, but these nets are connected differently, forming the Mo{sub 2}FeB{sub 2} crystal structure. A search of the literature revealed that compounds with the composition R{sub 2}XM{sub 2} (R=Sc, Y, Ti, Zr, Hf, rare earth; X=main group element; M=transition metal, Si, Ge) crystallize in one of four crystal structures: the Mo{sub 2}FeB{sub 2}, Zr{sub 3}Al{sub 2}, Mn{sub 2}AlB{sub 2} and W{sub 2}CoB{sub 2} crystal structures. These crystal structures are described, and the relationships between them are highlighted. Gd{sub 2}AlGe{sub 2} forms an entirely new crystal structure, and the details of its synthesis and characterization are given. Electronic structure calculations are performed to understand the nature of bonding in this compound and how electrons can be accounted for. A series of electronic structure calculations were performed on models with the U{sub 3}Si{sub 2} and Zr{sub 3}Al{sub 2} structures, using Zr and A1 as the building blocks. The starting point for these models was the U{sub 3}Si{sub 2} structure, and models were created to simulate the transition from the idealized U{sub 3}Si{sub 2} structure to the distorted Zr{sub 3}Al{sub 2} structure. Analysis of the band structures of the models has shown that the transition from the U{sub 3}Si{sub 2} structure to the Zr{sub 3}Al{sub 2} structure lifts degeneracies along the {Lambda} {yields} Z direction, indicating a Peierls-type mechanism for the displacement occurring in the positions of the Zr atoms.

Sean William McWhorter

2006-05-01T23:59:59.000Z

306

NiW and NiRu Bimetallic Catalysts for Ethylene Steam Reforming: Alternative Mechanisms for Sulfur Resistance  

SciTech Connect

Previous investigations of Ni-based catalysts for the steam reforming of hydrocarbons have indicated that the addition of a second metal can reduce the effects of sulfur poisoning. Two systems that have previously shown promise for such applications, NiW and NiRu, are considered here for the steam reforming of ethylene, a key component of biomass derived tars. Monometallic and bimetallic Al{sub 2}O{sub 3}-supported Ni and W catalysts were employed for ethylene steam reforming in the presence and absence of sulfur. The NiW catalysts were less active than Ni in the absence of sulfur, but were more active in the presence of 50 ppm H{sub 2}S. The mechanism for the W-induced improvements in sulfur resistance appears to be different from that for Ru in NiRu. To probe reasons for the sulfur resistance of NiRu, the adsorption of S and C{sub 2}H{sub 4} on several bimetallic NiRu alloy surfaces ranging from 11 to 33 % Ru was studied using density functional theory (DFT). The DFT studies reveal that sulfur adsorption is generally favored on hollow sites containing Ru. Ethylene preferentially adsorbs atop the Ru atom in all the NiRu (111) alloys investigated. By comparing trends across the various bimetallic models considered, sulfur adsorption was observed to be correlated with the density of occupied states near the Fermi level while C{sub 2}H{sub 4} adsorption was correlated with the number of unoccupied states in the d-band. The diverging mechanisms for S and C{sub 2}H{sub 4} adsorption allow for bimetallic surfaces such as NiRu that enhance ethylene binding without accompanying increases in sulfur binding energy. In contrast, bimetallics such as NiSn and NiW appear to decrease the affinity of the surface for both the reagent and the poison.

Rangan, M.; Yung, M. M.; Medlin, J. W.

2012-06-01T23:59:59.000Z

307

Instability, intermixing and electronic structure at theepitaxialLaAl...  

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

intermixing and electronic structure at the epitaxialLaAlO3SrTiO3(001) heterojunction. Instability, intermixing and electronic structure at the epitaxialLaAlO3...

308

Optical properties of ??-CoAl  

Science Journals Connector (OSTI)

The optical absorptance of ??-CoAl in the (0.1-2.5)-eV region was measured and analyzed by the Kramers-Kronig method. The optical conductivity shows interband features beginning below 0.1 eV, with several structures below 2 eV. These structures agree with those calculated from the energy bands of Moruzzi, Williams, and Gelatt. The experimentally observed systematics in CoAl and NiAl confirm our previous interpretation of the spectra of ??-NiAl, and disagree with other experimental and theoretical attempts to understand the optical properties of these compounds.

D. W Lynch; B. R. Boeke; D. J. Peterman

1982-04-15T23:59:59.000Z

309

ALS superbend magnet system  

SciTech Connect

The Lawrence Berkeley National Laboratory is preparing to upgrade the Advanced Light Source (ALS) with three superconducting dipoles (Superbends). In this paper we present the final magnet system design which incorporates R&D test results and addresses the ALS operational concerns of alignment, availability, and economy. The design incorporates conduction-cooled Nb-Ti windings and HTS current leads, epoxy-glass suspension straps, and a Gifford-McMahon cryocooler to supply steady state refrigeration. We also present the current status of fabrication and testing.

Zbasnik, J.; Wang, S.T.; Chen, J.Y.; DeVries, G.J.; DeMarco, R.; Fahmie, M.; Geyer, A.; Green, M.A.; Harkins, J.; Henderson, T.; Hinkson, J.; Hoyer, E.H.; Krupnick, J.; Marks, S.; Ottens, F.; Paterson, J.A.; Pipersky, P.; Portmann, G.; Robin, D.A.; Schlueter, R.D.; Steier, C.; Taylor, C.E.; Wahrer, R.

2000-09-15T23:59:59.000Z

310

INFLUENCE OF GIBBSITE SURFACE AREA AND CITRATE ON Ni SORPTION MECHANISMS AT pH 7.5  

E-Print Network (OSTI)

INFLUENCE OF GIBBSITE SURFACE AREA AND CITRATE ON Ni SORPTION MECHANISMS AT pH 7.5 NORIKO U the sorption of Ni to gibbsite of two different surface areas at pH 7.5, in the presence and absence of citrate to elucidate the sorption mechanisms at the molecular level. In agreement with former results, Ni-Al layered

Sparks, Donald L.

311

Deformation mechanisms in TiAl/Ti{sub 3}Al structures  

SciTech Connect

The deformation behavior of two-phase titanium aluminide alloys with different microstructures has been investigated in a wide temperature range using deformation tests and electron microscope observations. The structure of lamellar interfaces was characterized with respect to their role as dislocation sources. Thermally activated processes governing the dislocation mobility were characterized in terms of activation volumes and activation energies. The analysis is aimed at the identification of the dislocation processes operating under deformation conditions which are relevant for practical applications.

Appel, F.; Wagner, R. [GKSS Research Center, Geesthacht (Germany). Inst. for Materials Research

1995-12-31T23:59:59.000Z

312

Ann bay lodyans 3 / se Bryant Freeman ("Tonton Liben") ki pare ti liv sa a  

E-Print Network (OSTI)

la di: "Sa fe 2 fwa." Bourik la fe yon twazyem fopa. Neg la desann bourik la ak madanm li, epi li touye bourik la. Madanm li di: "Poukisa ou fe sa?" Neg la d i : " S a fe yon fwa." Se konsa zarenyen te | r p rive touye ni ti sourit, ni YMk c n.... "Monkonpe Chen, m raze net. Ou pa ta gen yon ti pyas prete m? M a remet ou li denmen a midi." Konpe Chen di li: "Men, pran sa. Denmen a midi m a pase chache li." Zarenyen reponn li: 2 "Wi, pa gen pwoblem. Ou met vini, m ap pare pou ou." Apre sa...

Freeman, Bryant C., ed.

2000-01-01T23:59:59.000Z

313

Semiconducting p-type MgNiO:Li epitaxial films fabricated by cosputtering method  

SciTech Connect

Li-doped ternary Mg{sub x}Ni{sub 1-x}O thin films were deposited on (0001) Al{sub 2}O{sub 3} substrates by a radio frequency (RF) magnetron cosputtering method with MgO and NiO:Li targets. The Mg mole fraction and Li content were relatively controlled by changing RF power for the MgO target over a range of 0-300 W, while the NiO:Li target was kept at 150 W. As a result, all films were epitaxially grown on (0001) Al{sub 2}O{sub 3} substrates with the relationship of [110]{sub NiO}||[1110]{sub Al2O3}, [112]{sub NiO}||[2110]{sub Al2O3} (in-plane), and [111]{sub NiO}||[0001]{sub Al2O3} (out-of-plane), and showed p-type semiconducting properties. Furthermore, from x-ray diffraction patterns, the authors found that MgO was effectively mixed with NiO:Li without structural deformation due to low lattice mismatch (0.8%) between NiO and MgO. However, the excess Li contents degraded the crystallinity of the MgNiO films. The band-gap of films was continuously shifted from 3.66 eV (339 nm) to 4.15 eV (299 nm) by the RF power of the MgO target. A visible transmittance of more than 80% was exhibited at RF powers higher than 200 W. Ultimately, the electrical resistivity of p-type MgNiO films was improved from 7.5 to 673.5 {Omega}cm, indicating that the Li-doped MgNiO films are good candidates for transparent p-type semiconductors.

Kwon, Yong Hun; Chun, Sung Hyun; Cho, Hyung Koun [School of Advanced Materials Science and Engineering, Sungkyunkwan University, 300 Cheoncheon-dong, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of)

2013-07-15T23:59:59.000Z

314

Interaction of coupled titanium and phosphorous on USY to tune hydrodesulfurization of 4,6-DMDBT and FCC LCO over NiW catalyst  

Science Journals Connector (OSTI)

Abstract There is growing interest in modifying USY in hydrotreating catalysts to obtain higher activity. This study provides a preliminary investigation of the interaction of titanium-phosphorus modification on USY (TiPY) and their influence on NiW-based catalyst containing USY and hydrodesulfurization (HDS) performances of 4,6-DMDBT (4,6-dimethyldibenzothiophene) and FCC LCO (fluid catalytic cracking diesel oil). Single titanium (TiY) and single phosphorus (PY) modified USY are studied simultaneously to provide further insight into how the interaction influence performance. The interaction between titanium and phosphorus on USY significantly enriched surface aluminum, and promoted the acidity and framework dealumination compared to TiY, PY and parent USY. NiW-based catalyst containing TiPY (NiW/TiPYA) had higher WS2 stacking numbers and more acidity than the catalysts containing TiY or PY. The higher HDS performance was observed with NiW/TiPYA due to the synergistic effect of WS2 stacking numbers and acidity among the catalysts, where the conversion of 4,6-DMDBT and sulfur in FCC LCO was 74.3% and 98.3%, respectively. The results can provide further insight into USY modification and its influence on hydrotreating catalysts.

Yandan Wang; Baojian Shen; Jiangcheng Li; Bing Feng; Xiaohui Li; Shenyong Ren; Qiaoxia Guo

2014-01-01T23:59:59.000Z

315

On the remarkable optical and structural transformations in Mg-Ti-H thin  

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

On the remarkable optical and structural transformations in Mg-Ti-H thin On the remarkable optical and structural transformations in Mg-Ti-H thin films Speaker(s): Dana Borsa Date: October 16, 2006 - 12:00pm Location: 90-3122 Seminar Host/Point of Contact: Venkat Srinivasan In searching for battery electrode materials, Mg-Ti-H thin films triggered much interest with its hydrogen storage capacity of approx. 4 times larger than that of conventional NiMH batteries [1]. Besides this, the same system has also absolutely remarkable optical properties [2]. Highly reflective in the metallic state, the films become highly absorbing upon hydrogen absorption. Mg0.80Ti0.20Hx thin films combine a high absorption (87% of the solar spectrum) with a low thermal emissivity (only 10%), while after removal of hydrogen Mg0.80Ti0.20 absorbs no more than 1/3 of the solar

316

Darlington AL O'Reillys AL  

E-Print Network (OSTI)

CanungraCk Darlington AL Darlington Coom era R O'Reillys AL Beechmont AL Binna Burra AL BackCk Tyungun AL Numinbah Valley AL NerangR Natural Bridge Numinbah AL Little Nerang Dam AL Albert R Bromfleet AL Benobble AL Wolffdene AL Luscombe AL Wongawallan AL Mt Tamborine Canungra Pimpama R Laheys Lookout

Greenslade, Diana

317

LBNL-4183E-rev1 N NA AT TU UR RA AL L G GA AS S V VA AR RI  

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

4183E-rev1 4183E-rev1 N NA AT TU UR RA AL L G GA AS S V VA AR RI IA AB BI IL LI IT TY Y I IN N C CA AL LI IF FO OR RN NI IA A: : E EN NV VI IR RO ON NM ME EN NT TA AL L I IM MP PA AC CT TS S A AN ND D D DE EV VI IC CE E P PE ER RF FO OR RM MA AN NC CE E E EX XP PE ER RI IM ME EN NT TA AL L E EV VA AL LU UA AT TI IO ON N O OF F I IN NS ST TA AL LL LE ED D C CO OO OK KI IN NG G E EX XH HA AU US ST T F FA AN N P PE ER RF FO OR RM MA AN NC CE E Brett C. Singer, William W. Delp and Michael G. Apte Indoor Environment Department Atmospheric Sciences Department Environmental Energy Technologies Division July 2011 (Revised February 2012) Disclaimer 1 This document was prepared as an account of work sponsored by the United States Government. While this document is believed to contain correct information, neither the United States Government nor any agency thereof, nor The Regents of the University of California, nor any of

318

Effect of Composition on the Solidification Behavior of Several Ni-Cr-Mo and Fe-Ni-Cr-Mo Alloys  

E-Print Network (OSTI)

simulate the solidifi- cation behavior of dissimilar welds made between AL-6XN and Ni-base filler metals.[3 differential thermal analysis (DTA) samples and welded specimens. This explains the in- variance of the amount of eutectic constituent observed in the microstructure in the welded and DTA conditions. Multicomponent

DuPont, John N.

319

O Ti-tE LOVE  

Office of Legacy Management (LM)

' ItqQtJulRl' IICt' O Ti-tE LOVE ~t?Al. . . At2D Al.CLkTED IChTTEtt~ . ' . . . : . ' . i I . . . . .mr TttE HOt\' ORAULE~ STANLEY FItZl:; SFCAKER ' . : ,J WE\J i' ORti STATE ASSH' rtrLY l r . . isay 29,.1980 Consultant to the Kew York ' , .' .I, " ..' . ,"' ! -. . . : . . . I.. . . . . ~. ,:- 9.. :. .' , * Ill . ,.. , ,i / All . ' %: : . : . . -. ;:. * :... . _ -. .' . . . I . ' J n' f armed. ?%c firtdingo and backup documentatiin embodied in thi preliminafy report compel the Task Yorao to call trprm ym; thr: . . I SpcnXer, to cwthorim crnd ompowcr the Assemly Sta?ding,CozmiCte I ' . : ,. . ..: .I' .,' :. .~.. ,:. :,-"'. ; ..d ::. . . .~~ ' .,' .' . : ' , ' ..,, -. . -. . . : : ? :. . . . .; *. . 1 ,.' .i. . . : \. .- :. " ' . . . c. : . I ! .'

320

E-Print Network 3.0 - al si ca Sample Search Results  

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

Summary: and Gibbs 1976). 12;KROEKER ET AL.: OXYGEN-17 NMR OF GLASSY AND CRYSTALLINE TITANITE 575 CaTiSiO5 glass... ; Lee and Stebbins 2000; Zhao et al. 2000). The spectra for...

Note: This page contains sample records for the topic "ni ti al" 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

Developing TiAIN Coatings for Intermediate Temperature-Solid Oxide Fuel Cell Interconnect Applications  

SciTech Connect

TiN-type coatings have potential to be used as SOFC interconnect coatings SOFC because of their low resistance and high temperature stability. In this research, various (Ti,Al)N coatings were deposited on stainless steels by filtered-arc method. ASR and XRD tests were conducted on these coatings, and SEM/EDAX analysis were conducted after ASR and XRD tests. SEM/EDAX analyses show that (Ti,Al)N remains stable at temperature up to 700°C. It is also indicated that Al has beneficial effect on the stability of TiN type coatings. At 900°C, (Ti-30Al)N is fully oxidized and some of (Ti-50Al)N coating still remains as nitride. The analyses on cross-sectional samples show that these coatings are effective barrier to the Cr migration. In summary, (Ti.Al)N coatings are good candidates for the SOFC interconnect applications at 700°C. The future directions of this research are to improve the stability of these coatings by alloy-doping and to develop multi-layer coatings.

Liu, X. (West Virginia University); Johnson, C.D.; Li, C. (West Virginia University); Xu, J. (West Virginia University); Cross, C.

2007-02-01T23:59:59.000Z

322

A Low Noise NbTiN-based 850 GHz SIS Receiver for the  

E-Print Network (OSTI)

the 350 micron atmospheric window. This frequency band lies entirely above the energy gap of niobium (700 that consists of two Nb/AlN/NbTiN tunnel junctions, NbTiN thin-film microstrip tuning elements, and a Nb window was deployed at the CSO. It used a novel 1 µm thick Silicon Nitride membrane which support an all

323

Steam Reforming of Methane over Ni Catalysts Prepared from Hydrotalcite-Type Precursors: Catalytic Activity and Reaction Kinetics  

Science Journals Connector (OSTI)

Abstract Ni/Mg-Al catalysts derived from hydrotalcite-type precursors were prepared by a co-precipitation technique and applied to steam reforming of methane. By comparison with Ni/?-Al2O3 and Ni/?-Al2O3 catalysts prepared by incipient wetness impregnation, the Ni/Mg-Al catalyst presented much higher activity as a result of higher specific surface area and better Ni dispersion. The Ni/Mg-Al catalyst with a Ni/Mg/Al molar ratio of 0.5:2.5:1 exhibited the highest activity for steam methane reforming and was selected for kinetic investigation. With external and internal diffusion limitations eliminated, kinetic experiments were carried out at atmospheric pressure and over a temperature range of 823 ? 973 K. The results demonstrated that the overall conversion of CH4 and the conversion of CH4 to CO2 were strongly influenced by reaction temperature, residence time of reactants as well as molar ratio of steam to methane. A classical Langmuir-Hinshelwood kinetic model proposed by Xu and Froment (1989) fitted the experimental data with excellent agreement. The estimated adsorption parameters were consistent thermodynamically.

Yang Qi; Zhenmin Cheng; Zhiming Zhou

2014-01-01T23:59:59.000Z

324

ALS@20  

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

feed-image feed-image Digg: ALSBerkeleyLab Facebook Page: 208064938929 Flickr: advancedlightsource Twitter: ALSBerkeleyLab YouTube: AdvancedLightSource Home About the ALS ALS@20 ALS@20 ALS@20 Kick-Off Celebration Print On Friday, January 11, the Advanced Light Source celebrated the beginning of its 20th anniversary year with a brunch attended by more than 150 current and past staff members. After introductory remarks describing the trials and tribulations encountered during the construction of the ALS from former Director Jay Marx, current ALS Scientific Director Steve Kevan and Director Roger Falcone talked about the progress of the facility over the years. Attendees were then able to view more than 500 historical photos of the ALS and its staff displayed around the room.

325

Ann bay lodyans 7 / se Bryant Freeman ("Tonton Liben") ki pare ti liv sa a  

E-Print Network (OSTI)

pou I pase akote. Ti djab la bare I: "Kwa kwa kwa! Ala chans m genyen jodi a. Mwen chita chita m, epi yon vyann vin jwenn mwen. Ki kote ou prale, ti neg?" Dyedone komanse tranble. Men li C^*M pran kouraj li ak 2 men, li pran chante pou ti djab... m pito pa vann." 2 Wa a karese Malis, li pwomet li tout pwoteksyon. Alafen, li louvri men Malis, li depoze san dola ladann. Le msye we bel fey lajan, li dako pou ba Wa a ti lanp la. Epi, nan denmen, Malis al achte yon vye bourik ak kob la...

Freeman, Bryant C., ed.

2000-01-01T23:59:59.000Z

326

Bimetallic Ni-Rh catalysts with low amounts of Rh for the steam and autothermal reforming of n-butane for fuel-cell applications.  

SciTech Connect

Mono-metallic nickel and rhodium catalysts and bimetallic Ni-Rh catalysts supported on La-Al{sub 2}O{sub 3}, CeZrO{sub 2} and CeMgOx were prepared and evaluated for catalyzing the steam and autothermal reforming of n-butane. The binary Ni-Rh supported on La-Al{sub 2}O{sub 3} catalysts with low weight loading of rhodium exhibited higher H{sub 2} yields than Ni or Rh alone. The Ni-Rh/CeZrO{sub 2} catalyst exhibited higher performance and no coke formation, compared to the same metals on other supports. A NiAl{sub 2}O{sub 4} spinel phase was obtained on all Ni and Ni-Rh catalysts supported on La-Al{sub 2}O{sub 3}. The presence of rhodium stabilized the spinel phase as well as NiOx species upon reforming while Ni alone was mostly reduced into metallic species. Extended X-ray absorption fine-structure analysis showed evidence of Ni-Rh alloy during preparation and even further after an accelerated aging at 900C in a H{sub 2}/H{sub 2}O atmosphere.

Ferrandon, M.; Kropf, A. J.; Krause, T.; Chemical Sciences and Engineering Division

2010-05-15T23:59:59.000Z

327

Industry @ ALS  

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

Industry @ ALS Industry @ ALS Industry @ ALS Concrete Industry Benefits from Ancient Romans and the ALS Print Thursday, 17 October 2013 14:24 New insights into the Romans' ingenious concrete harbor structures emerging from ALS beamline research could move the modern concrete industry toward its goal of a reduced carbon footprint. Summary Slide Read more... Moving Industry Forward: Finding the Environmental Opportunity in Biochar Print Thursday, 12 September 2013 08:41 Using ALS Beamlines 10.3.2 and 8.3.2, the Environmental Protection Agency (EPA) is currently investigating how biochar sorbs environmental toxins and which kinds of biochar are the most effective. The possibilities for widespread use have already launched entrepreneurial commercial ventures. Summary Slide

328

ALS Visitors  

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

including Ethan Crumlin (at right) about current research in energy storage and battery efficiency. Berkeleyside Editor Lance Knoble toured the ALS and Berkeley Lab with...

329

Transition metal atoms pathways on rutile TiO{sub 2} (110) surface: Distribution of Ti{sup 3+} states and evidence of enhanced peripheral charge accumulation  

SciTech Connect

Charge transfer between metal nanoparticles and the supported TiO{sub 2} surface is primarily important for catalytic applications as it greatly affects the catalytic activity and the thermal stability of the deposited nanoparticles on the surface. Herein, systematic spin-polarized density functional and HSE06 calculations are performed to evaluate the adsorption, diffusion, and charge state of several transition metal monomers on both stoichiometric and reduced rutile TiO{sub 2} (110) surface. Although the presence of oxygen vacancy (O{sub v}) increases the binding of Au, Pt and Pd on the surface, it weakens the interaction thus enhancing the diffusion for Fe, Co, Ni, Ag, and Cu adatoms on the surface. For pristine reduced surface, only a small portion (around 5%) of the excess electrons occupy the topmost surface, which are mainly delocalized at the second nearest and third nearest fivefold coordinated Ti (Ti{sub 5c}) atoms. Excess electrons populating at the Ti{sub 5c} atoms on the basal plane can be transferred to strongly electronegative adsorbates like Au and Pt thus enabling a moderate adsorption at this site, whereas no stable adsorption is found for other less electronegative transition metal adatoms (Ag, Cu, Fe, Co, Ni, and Pd) on the reduced surface and for all the adatoms on stoichiometric surface. This result clarifies the origin of the experimental observation of the adsorption of O{sub 2} and CO molecules at Ti{sub 5c} sites in connection with charge transfer. In addition, the spatial redistribution of the excess electrons around the O{sub v} upon the adsorption of the monomers is thoroughly examined. Our finding of an accumulation of excess electrons at the Ti{sub 5c} sites around the monomers explains the critical role of the perimeter interface of the deposited nanoparticles in promoting the adsorption and activation of reactants observed in experiments.

Cai Yongqing; Bai Zhaoqiang; Chintalapati, Sandhya; Feng Yuanping [Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore); Zeng Qingfeng [School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an 710072 (China)

2013-04-21T23:59:59.000Z

330

Rumpling phenomenon in platinum modified Ni-Al alloys  

SciTech Connect

Surface undulations known as rumpling have been shown to develop at the surface of bond coats used in advanced thermal barrier coating systems. Rumpling can result in cracking and eventual spallation of the top coat. Many mechanisms to explain rumpling have been proposed, and among them is a martensitic transformation. High-temperature x-ray diffraction, differential scanning calorimetry and potentiometry were used to investigate the nature of the martensitic transformation in bulk platinum-modified nickel aluminides. It was found that the martensitic transformation has strong time dependence and can form over a range of temperatures. Cyclic oxidation experiments were performed on the bulk alloys to investigate the effect of the martensitic transformation on surface rumpling. It was found that the occurrence of rumpling was associated with the martensitic transformation. The degree of rumpling was found to increase with an increasing number of cycles and was independent of the heating and cooling rates used. The thickness of the oxide layer at the surface of the samples had a significant impact on the amplitude of the resulting undulations, with amplitude increasing with increasing oxide-layer thickness. Rumpling was also observed in an alloy based on the {gamma}-{gamma}' region of the nickel-aluminum-platinum phase diagram. Rumpling in this alloy was found to occur during isothermal oxidation and is associated with a subsurface layer containing a platinum-rich phase known as a. Rumpling in both alloy systems may be explained by creep deformation of a weakened subsurface layer in response to the compressive stresses in the thermally grown oxide layer.

Zimmerman, Benjamin Joseph

2005-05-01T23:59:59.000Z

331

ALS Visitors  

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

ALS Visitors ALS Visitors ALS Visitors Print Wednesday, 29 July 2009 00:00 ALS staff members host a variety of scientific, educational, government, and community-related tours each month. November 2013 poneman U.S. Deputy Secretary of Energy Daniel Poneman visited Berkeley Lab on Friday, Nov. 15, during a brief stay in the Bay Area. Glenn Mara of the University of California Office of the President and Aundra Richards of the DOE Berkeley Site Office joined Deputy Laboratory Director Horst Simon's welcome. They updated Poneman on the lab's future initiatives and current capital projects and heard briefings on cyber security, computing, and the Joint BioEnergy Institute. As second-in-command at DOE, Poneman is responsible for assisting the Secretary of Energy in the management and operations of the agency and acting on his behalf when necessary.During his tour of the ALS, Poneman (right) spoke with Ken Goldberg (Materials Sciences Division) at the CXRO beamline.

332

First-Principles Study of MetalCarbide/Nitride Adhesion: Al/VC vs. Al/VN Donald J. Siegel  

E-Print Network (OSTI)

-oxide ce- ramics. Within this class, the transition metal carbides and ni- trides are a particularly knowledge, there have been only three studies of adhesion between metals and transition metal carbidesFirst-Principles Study of Metal­Carbide/Nitride Adhesion: Al/VC vs. Al/VN Donald J. Siegel

Adams, James B

333

Giant Quadrupole-Resonance in Ni Isotopes  

E-Print Network (OSTI)

Inelastic scattering of 129 MeV alpha particles has been used to excite the giant quadrupole resonance in Ni-58, Ni-60, Ni-62, Ni-64. The resonance was found to exhaust 58 +/- 12%, 76 +/- 14%, 78 +/- 14%, and 90 +/-16% of the E2 energy-weighted sum...

Youngblood, David H.; Lui, YW; Garg, U.; Peterson, R. J.

1992-01-01T23:59:59.000Z

334

ALS Visitors  

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

ALS Visitors Print ALS Visitors Print ALS staff members host a variety of scientific, educational, government, and community-related tours each month. November 2013 poneman U.S. Deputy Secretary of Energy Daniel Poneman visited Berkeley Lab on Friday, Nov. 15, during a brief stay in the Bay Area. Glenn Mara of the University of California Office of the President and Aundra Richards of the DOE Berkeley Site Office joined Deputy Laboratory Director Horst Simon's welcome. They updated Poneman on the lab's future initiatives and current capital projects and heard briefings on cyber security, computing, and the Joint BioEnergy Institute. As second-in-command at DOE, Poneman is responsible for assisting the Secretary of Energy in the management and operations of the agency and acting on his behalf when necessary.During his tour of the ALS, Poneman (right) spoke with Ken Goldberg (Materials Sciences Division) at the CXRO beamline.

335

Al Weinrub  

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

Al Weinrub Al Weinrub Author, "COMMUNITY POWER: Decentralized Renewable Energy in California" Member, Sierra Club California Clean Energy-Climate CommitteeMember, Steering Committee, Bay Area Clean Energy Alliance al.weinrub@comcast.net This speaker was a visiting speaker who delivered a talk or talks on the date(s) shown at the links below. This speaker is not otherwise associated with Lawrence Berkeley National Laboratory, unless specifically identified as a Berkeley Lab staff member. Al Weinrub is a member of the Sierra Club California Energy-Climate Committee and serves on the Steering Committee of the Bay Area's Local Clean Energy Alliance. He is the author of COMMUNITY POWER: Decentralized Renewable Energy in California (http://www.localcleanenergy.org/Community-Power-Publication)

336

Active Oxygen on Au/TiO2 Catalysts DOI: 10.1002/anie.201102062 Active oxygen on a Au/TiO2 catalyst Formation, stability and CO  

E-Print Network (OSTI)

1 Active Oxygen on Au/TiO2 Catalysts DOI: 10.1002/anie.201102062 Active oxygen on a Au/TiO2 are the activation of molecular oxygen, the active site for this reaction step, and the nature of the catalytically active oxygen species present under working conditions.[3;9-15] Stiehl et al. had shown that molecularly

Pfeifer, Holger

337

Laser Cladding of \\{MCrAlY\\} Coatings on Stainless Steel  

Science Journals Connector (OSTI)

Abstract \\{MCrAlY\\} alloys (where M stands for Ni,Co or both) are commonly used as overlay protective coatings in gas turbine engine components against high temperature oxidation and corrosion. The protective effect of these alloys is due to the formation of a continuous thermally stable oxide layer on the coating surface. In this work several types of \\{MCrAlY\\} alloys, differing in their elemental composition, have been deposited on austenitic stainless steel by means of laser cladding. The microstructure of the coatings have been characterized by SEM-EDSand XRD. As expected, elemental composition compatible with ?Ni/?’ Ni3Al,?Ni/?-NiAl or ?Co/?-(Co,Ni)Al phases are observed in hypoeutectic or hypereutectic microstructures depending on the alloy composition. The high temperature oxidation behavior of the coatings was evaluated by air furnace oxidation tests at 1100 °C for 200 h. The oxidized surface of the samples was examined by SEM-EDS and the oxides present identified by theoretical stoichiometric calculations. Results indicate the formation of a uniform Al3O2protective oxide scale with NiO,CoO, Y2O3/YAlO3 and Cr2O3 oxide inclusions.

M.J. Tobar; J.M. Amado; A. Yáñez; J.C. Pereira; V. Amigó

2014-01-01T23:59:59.000Z

338

Bulk Migration of Ni/NiO in Ni-YSZ during Reducing Conditions...  

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

random grain orientation. The surface analysis and mapping were carried out using ToF-SIMS and AES whereas EDS maps on FIB sliced areas on Ni-YSZ were utilized for the bulk...

339

ALS Visitors  

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

Quick Facts Quick Facts ALS Visitors Print ALS staff members host a variety of scientific, educational, government, and community-related tours each month. November 2013 poneman U.S. Deputy Secretary of Energy Daniel Poneman visited Berkeley Lab on Friday, Nov. 15, during a brief stay in the Bay Area. Glenn Mara of the University of California Office of the President and Aundra Richards of the DOE Berkeley Site Office joined Deputy Laboratory Director Horst Simon's welcome. They updated Poneman on the lab's future initiatives and current capital projects and heard briefings on cyber security, computing, and the Joint BioEnergy Institute. As second-in-command at DOE, Poneman is responsible for assisting the Secretary of Energy in the management and operations of the agency and acting on his behalf when necessary.During his tour of the ALS, Poneman (right) spoke with Ken Goldberg (Materials Sciences Division) at the CXRO beamline.

340

Novel Au-TiC Catalysts for CO Oxidation and Desulfurization Processes  

SciTech Connect

Recent articles dealing with the physical and chemical properties of novel Au-TiC catalysts are reviewed. High-resolution photoemission, scanning tunneling microscopy and first-principles periodic density-functional calculations were used to study the deposition of gold on a TiC(0 0 1) surface. Gold grows forming two-dimensional (very low coverage) and three-dimensional (medium and large coverage) islands on the carbide substrate. A positive shift in the binding energy of the C 1s core level is observed after the deposition of Au on TiC(0 0 1). The results of the density-functional calculations corroborate the formation of Au-C bonds. In general, the bond between Au and the TiC(0 0 1) surface exhibits very little ionic character, but there is a substantial polarization of electrons around Au that facilitates bonding of the adatoms with electron-acceptor molecules (CO, O{sub 2}, C{sub 2}H{sub 4}, SO{sub 2}, thiophene, etc.). Experimental measurements indicate that Au/TiC(0 0 1) is a very good catalysts for the oxidation of CO, the destruction of SO{sub 2} and the hydrodesulfurization of thiophene. At temperatures below 200 K, Au/TiC(0 0 1) is able to perform the 2CO + O{sub 2} {yields} 2CO{sub 2} reaction and the full decomposition of SO{sub 2}. Furthermore, in spite of the very poor hydrodesulfurization performance of TiC(0 0 1) or Au(1 1 1), a Au/TiC(0 0 1) surface displays a hydrodesulfurization activity higher than that of conventional Ni/MoS{sub x} catalysts. Metal carbides are excellent supports for enhancing the chemical reactivity of gold. The Au/TiC system is more chemically active than systems generated by depositing Au nanoparticles on oxide surfaces.

J Rodriguez; P Liu; Y Takahashi; F Vines; L Feria; E Florez; K Nakamura

2011-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "ni ti al" 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

E-Print Network 3.0 - al-fe alloys strukturnyj Sample Search...  

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

Theory NiAl CoAl FeAl CoGa PdIn VT,1 A Q M 1, 0 128, 0 144... , with transition-metal vacancies (VT) for T-deficient ... Source: Collins, Gary S. - Department of Physics...

342

The Obviative Suffix -ni- In Algonquian  

E-Print Network (OSTI)

the marker -ni- is used specifically when an argument has been established as obviative earlier in the discourse. By tracing -ni- in the morphology of Fox and Kickapoo and in Bloomfield's comparative Algonquian work (Bloomfield 1946), the present paper...

Gathercole, Geoffrey

1979-01-01T23:59:59.000Z

343

Monopole Strength in Ni-58  

E-Print Network (OSTI)

PHYSICAL REVIEW C VOLUME 44, NUMBER 5 Monopole strength in Ni NOVEMBER 1991 D. H. Youngblood and Y.-W. Lui Cyclotron Institute, Texas AdkM Uni Uersi ty, College Station, Texas 77843 (Received 20 June 1991) Differential cross-section data from... of Ener- gy under Grant No. DE-FG05-86ER40256. MONOPOLE STRENGTH IN "Ni 1881 [1]D. H. Youngblood, P. Bogucki, J. D. Bronson, U. Garg, Y.-W. Lui, and C. M. Rozsa, Phys. Rev. C 23, 1997 (1981). [2] M. Buenerd, J. Phys. C 4, 115 (1984). [3] S...

Youngblood, David H.; Lui, YW.

1991-01-01T23:59:59.000Z

344

E-Print Network 3.0 - al hf ta Sample Search Results  

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

a JEOL electron microprobe and Ca, Ti, Nb, Ta, Hf and Zr abundances measured using laser ablation... for an Al-rich chon- drule. As Figure 1 shows there is little evidence for...

345

Effects of Point Defects and Impurities on Kinetics in NaAlH4  

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

A presentation showing that point defects play an important role in the kinetics of NaAlH4 including vacancies and interstitials consistent with observed effects of Ti.

346

E-Print Network 3.0 - al metal irradiated Sample Search Results  

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

Accelerator Beams , H. Ludewig1 Summary: effects on CTE of super-Invar. Figure 3: "Gum Metal" material characterization in its non-irradiated state... driver. Ti-6Al-4V....

347

E-Print Network 3.0 - al bulk crystals Sample Search Results  

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

are homogeneously dispersed in the residual glass of the bulk for Tc... consists of titanite (CaTiSiO5) and anorthite (CaAl2Si2O8) crystals that have nucleated heterogeneously......

348

Formation of Ti-B surface alloys by excimer laser mixing  

SciTech Connect

We have formed a surface Ti-B alloy by excimer laser mixing of a single B layer on a Ti-6Al-4V alloy substrate. Rutherford backscattering spectroscopy indicates a uniform B:Ti ratio of approximately 0.7 in the surface layer. A Boron layer 60 nm thick resulted in an alloy layer approximately 200 nm thick. There is little indication, by either Auger electron spectroscopy or nuclear reaction analysis, of substantial oxygen incorporation in the surface alloy despite the fact that the processing was done in air. Transmission electron microscopy of the surface alloy shows a completely amorphous surface layer underlain by a martensitic structure.

Jervis, T.R.; Nastasi, M.; Hirvonen, J.P.; Zocco, T.G.

1990-01-01T23:59:59.000Z

349

AL. I  

Office of Legacy Management (LM)

AL. I AL. I Department of Energy Washington, DC 20545 OCT 13 Vii87 Mr. John T. Shields A214 National Fertilizer Development Center Tennessee Valley Authority Muscle Shoals, Alabama 35660 Dear Mr. Shields: As you may know, the Department of Energy (DOE) is evaluating the radiological condition of sites that were utilized under the Manhattan Engineer District and the Atomic Energy Commission (AEC) during the early years of nuclear development to determine whether they need remedial action and whether the Department has authority to perform such action. AEC work at the TVA during the period 1951 through 1955 involved the development of a process to recover uranium from the production of phosphate fertilizer. A laboratory and pilot plant were operated at the site, but very little

350

Catalytic performances of Ni–CaO–mayenite in CO2 sorption enhanced steam methane reforming  

Science Journals Connector (OSTI)

Abstract Ni–CaO–mayenite (Ca12Al14O33) catalysts for the CO2 Sorption Enhanced Steam Methane Reforming (SE-SMR) have been developed using the microwave assisted self-combustion method of preparation. The sorption of CO2 by CaO shifts the steam reforming and the Water Gas Shift reaction (WGS) towards H2 production and favors the heat balance of the global reaction. The CO2 sorption has been studied on materials with different CaO/Ca12Al14O33 ratios and for different types of preparation. The specific surface area of materials, the temperature of Ni phases' reducibility and CO2 sorption are all essential for material efficiency. The Ni–CA75MM catalyst was the most active and stable in methane steam reforming with CO2 sorption, even at an unusually low temperature (650 °C).

Moisés R. Cesário; Braúlio S. Barros; Claire Courson; Dulce M.A. Melo; Alain Kiennemann

2015-01-01T23:59:59.000Z

351

Kinetics of Ni Sorption in Soils: Roles of Soil Organic Matter and Ni Precipitation  

SciTech Connect

The kinetics of Ni sorption to two Delaware agricultural soils were studied to quantitatively assess the relative importance of Ni adsorption on soil organic matter (SOM) and the formation of Ni layered double hydroxide (Ni-LDH) precipitates using both experimental studies and kinetic modeling. Batch sorption kinetic experiments were conducted with both soils at pH 6.0, 7.0, and 7.5 from 24 h up to 1 month. Time-resolved Ni speciation in soils was determined by X-ray absorption spectroscopy (XAS) during the kinetic experiments. A kinetics model was developed to describe Ni kinetic reactions under various reaction conditions and time scales, which integrated Ni adsorption on SOM with Ni-LDH precipitation in soils. The soil Ni speciation (adsorbed phases and Ni-LDH) calculated using the kinetics model was consistent with that obtained through XAS analysis during the sorption processes. Under our experimental conditions, both modeling and XAS results demonstrated that Ni adsorption on SOM was dominant in the short term and the formation of Ni-LDH precipitates accounted for the long-term Ni sequestration in soils, and, more interestingly, that the adsorbed Ni may slowly transfer to Ni-LDH phases with longer reaction times.

Shi, Zhenqing; Peltier, Edward; Sparks, Donald L. (Delaware); (Kansas)

2012-12-10T23:59:59.000Z

352

Role of polaron hopping in leakage current behavior of a SrTiO{sub 3} single crystal  

SciTech Connect

We studied the ionic/electronic transport and resistance degradation behavior of dielectric oxides by solving the electrochemical transport equations. Here, we took into account the non-periodical boundary conditions for the transport equations using the Chebyshev collocation algorithm. A sandwiched Ni|SrTiO{sub 3}|Ni capacitor is considered as an example under the condition of 1.0?V, 1.0??m thickness for SrTiO{sub 3} layer, and a temperature of 150?°C. The applied voltage resulted in the migration of ionic defects (oxygen vacancies) from anode towards cathode. The simulated electric potential profile at steady state is in good agreement with the recent experimental observation. We introduced the possibility of polaron-hopping between Ti{sup 3+} and Ti{sup 4+} at the electrode interface. It is shown that both the oxygen vacancy transport and the polaron-hopping contribute to the resistance degradation of single crystal SrTiO{sub 3}, which is consistent with the experimental observations.

Cao, Y., E-mail: yxc238@psu.edu; Randall, C. A.; Chen, L. Q. [Department of Materials Science and Engineering, Penn State University, University Park, Pennsylvania 16802 (United States); Bhattacharya, S. [Department of Materials Science and Engineering, Indian Institute of Technology Hyderabad, YM 502205 (India); Shen, J. [Department of Mathematics, Purdue University, West Lafayette, Indiana 47907 (United States)

2013-12-14T23:59:59.000Z

353

Thermodynamics of TiO{sub x} in blast furnace-type slags  

SciTech Connect

Equilibrium studies between CaO-SiO{sub 2}-10 pct MgO-Al{sub 2}O{sub 3}-TiO{sub 1.5}-TiO{sub 2} slags, carbon-saturated iron, and a carbon monoxide atmosphere were performed at 1773 K to determine the activities of TiO{sub 1.5} and TiO{sub 2} in the slag. These thermodynamic parameters are required to predict the formation of titanium carbonitride in the blast furnace. In order to calculate the activity of titanium oxide, the activity coefficient of titanium in carbon-saturated iron-carbon-titanium alloys was determined by measuring the solubility of titanium in carbon-saturated iron in equilibrium with titanium carbide. The solubility and the activity coefficient of titanium obtained were 1.3 pct and 0.023 relative to 1 wt pct titanium in liquid iron or 0.0013 relative to pure solid titanium at 1773 K, respectively. Over the concentration range studied, the effect of the TiO{sub x} content on its activity coefficient is small. In the slag system studied containing 35 to 50 pct CaO, 25 to 45 pct SiO{sub 2}, 7 to 22 pct Al{sub 2}O{sub 3}, and 10 pct MgO, the activity coefficients of TiO{sub 1.5} and TiO{sub 2} relative to pure solid standard states range from 2.3 to 8.8 and from 0.1 to 0.3, respectively. Using thermodynamic data obtained, the prediction of the formation of titanium carbonitride was made. Assuming hypothetical TiO{sub 2}, i.e., total titanium in the slag expressed as TiO{sub 2}, and using the values of the activity coefficients of TiO{sub 1.5} and TiO{sub 2} determined, the equilibrium distribution of titanium between blast furnace-type slags and carbon-saturated iron was computed. The value of [pct Ti]/(pct TiO{sub 2}) ranges from 0.1 to 0.2.

Morizane, Y.; Ozturk, B.; Fruehan, R.J. [Carnegie Mellon Univ., Pittsburgh, PA (United States). Dept. of Materials Science and Engineering

1999-02-01T23:59:59.000Z

354

Fabrication of functionally graded TiC/Ti composites by Laser Engineered Net Shaping  

E-Print Network (OSTI)

engineered net shaping (LENS), with compositions changing from pure Ti to approximately 95 vol% TiC; Microstructure; TiC carbide 1. Introduction Functionally graded materials (FGMs) are a class of advanced

DuPont, John N.

355

Hydrogen Production by Low-temperature Steam Reforming of Bio-oil over Ni/HZSM-5 Catalyst  

Science Journals Connector (OSTI)

We investigated high catalytic activity of Ni/HZSM-5 catalysts synthesized by the impregnation method, which was successfully applied for low-temperature steam reforming of bio-oil. The influences of the catalyst composition, reforming temperature and the molar ratio of steam to carbon fed on the stream reforming process of bio-oil over the Ni/HZSM-5 catalysts were investigated in the reforming reactor. The promoting effects of current passing through the catalyst on the bio-oil reforming were also studied using the electrochemical catalytic reforming approach. By comparing Ni/HZSM-5 with commonly used Ni/Al2O3 catalysts, the Ni20/ZSM catalyst with Ni-loading content of about 20% on the HZSM-5 support showed the highest catalytic activity. Even at 450 °C, the hydrogen yield of about 90% with a near complete conversion of bio-oil was obtained using the Ni20/ZSM catalyst. It was found that the performance of the bio-oil reforming was remarkably enhanced by the HZSM-5 supporter and the current through the catalyst. The features of the Ni/HZSM-5 catalysts were also investigated via X-ray diffraction, inductively coupled plasma and atomic emission spectroscopy, hydrogen temperature-programmed reduction, and Brunauer-Emmett-Teller methods.

Song-bai Qiu; Lu Gong; Lu Liu; Cheng-gui Hong; Li-xia Yuan; Quan-xin Li

2011-01-01T23:59:59.000Z

356

3d X 3d X SrTiO3Ti 2p 3d  

E-Print Network (OSTI)

XX 3d X 3d X X XX X XX SrTiO3Ti 2p 3d SrTiO3Ti 2p 3d 2p 2p SrTiO3 ts) 2p3/2 (t2g) 2p3/2 (e ) 2p1/2 (eg)2p SrTiO3 3d unit (t2g) (eg) (eg)2p1/2 (t2g)3d (Ti Fe Cu) arb. ( 2g) (Ti, Fe, Cu) y(ansitynten 3d In 3d 468464460456 · Photon Energy (e

Katsumoto, Shingo

357

Nuclear Magnetic Resonance in FeAl and CoAl  

Science Journals Connector (OSTI)

We have investigated the Al27 nuclear magnetic resonance in Ni3Al, NiAl, FeAl, and both the Al27 and Co59 resonances in CoAl. The cobalt resonance in CoAl exhibits a weakly temperature-dependent, positive shift. This shift (?1.5%) is too large to be accounted for solely by the hyperfine field from conduction electrons polarized by the external magnetic field, and orbital paramagnetic effects appear to be the dominant factor, core polarization playing a relatively minor role. The aluminum Knight shift in CoAl is small (0.014%) and temperature-independent. This is to be contrasted with aluminum in FeAl which exhibits a large, negative, temperature-dependent shift (-0.38% at 293°K). It is shown that both the large aluminum Knight shift in FeAl and the small aluminum Knight shift in CoAl are consistent with the predictions of the Ruderman-Kittel-Yosida (RKY) theory. However, it is now believed that the small shift observed in CoAl results from a lack of s character in the conduction-electron wave functions rather than from a node anticipated in the conduction-electron polarization. The temperature dependence of the resonance in FeAl can also be accounted for by the RKY mechanism if it is assumed that the temperature dependence of the magnetic susceptibility is associated with disorder in the material. This assumption is necessary because the Knight shift is not linearly related to the bulk susceptibility of the sample. The aluminum linewidth in FeAl increases as the temperature is lowered. At room temperature the linewidth is independent of magnetic field but greater than the calculated dipolar linewidth. At 77 and 4.2°K the linewidth increases with increasing magnetic field. This effect is attributed mainly to inhomogeneous Knight-shift broadening, although inhomogeneous magnetization broadening also contributes. A similar situation is observed in CoAl. At room temperature the cobalt and aluminum resonances have essentially the same width. The linewidths are independent of magnetic field but greater than the dipolar values. As the temperature is lowered the linewidths increase and become magnetic-field-dependent. The cobalt resonance broadens more severely than the aluminum resonance. It is believed that inhomogeneous Knight-shift broadening and inhomogeneous magnetization broadening determine the cobalt linewidth at low temperatures. The aluminum nuclei in CoAl do not exhibit appreciable hyperfine coupling with the conduction electrons, so that only inhomogeneous magnetization broadening contributes to the linewidth.

J. A. Seitchik and R. H. Walmsley

1965-01-04T23:59:59.000Z

358

AlGaN/GaN metal-oxide-semiconductor heterostructure field-effect transistors using barium strontium titanate  

E-Print Network (OSTI)

AlGaN/GaN metal-oxide-semiconductor heterostructure field-effect transistors using barium strontium-effect transistors have been formed by incorporating barium strontium titanate (BST) deposited by rf magnetron in increased leakage. Due to its large dielectric constant, barium strontium ti- tanate [Ba1-xSrxTiO3, (BST

York, Robert A.

359

Comment on the Evidence for a Monopole Resonance at Approximately 20 Mev in Ni-58  

E-Print Network (OSTI)

be accompanied by a brief abstract and a keyword abstract. Comment on the evidence for a monopole resonance at approximately 20 MeV in 5sNi U. Garg, P. Bogucki, J. D. Bronson, Y. -W. Lui, C. M. Rozsa, * and D. H. Youngblood Cyclotron Institute, Texas AckM... Uniuersity, College Station, Texas 77843 (Received 23 September 1981) Small-angle inelastic a scattering data for "Ni at 129 MeV have been reanalyzed with the giant resonance peak parameters suggested by Bertrand et al. The two components of the giant...

Garg, U.; Bogucki, P.; Bronson, J. D.; Lui, YW; Rozsa, C. M.; Youngblood, David H.

1982-01-01T23:59:59.000Z

360

Magnetism in Ni-Cu Alloys  

Science Journals Connector (OSTI)

On the assumption that in Ni-Cu alloys the spin moment on a Ni atom depends on the local atomic environment, it was possible to find moment values for the various atomic configurations so as to give average moments in reasonable quantitative agreement with the values measured in the ferromagnetic composition range. The local environment is specified by the number of Ni nearest neighbors and the number of Ni second-nearest neighbors. This model allows also a consistent qualitative interpretation of the effect on the average moment of low-temperature annealing treatment and of plastic deformation.

C. G. Robbins; Helmut Claus; Paul A. Beck

1969-06-16T23:59:59.000Z

Note: This page contains sample records for the topic "ni ti al" 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

Synergistic Effect of Nano-TiO2 and Nanoclay on the Ultraviolet Degradation and Physical Properties of Wood Polymer Nanocomposites  

Science Journals Connector (OSTI)

(7) The combination of nanoclay with other metal nanoparticles will influence the properties of the composites considerably, as reported by Laachachia et al. while studying the properties of poly(methyl methacrylate) (PMMA) nanocomposites prepared with TiO2 and nanoclay. ... (30) Mina et al. studied the XRD pattern of a polypropylene/titanium dioxide composite and reported a similar increase in the peak intensity of TiO2 in the composites. ...

Ankita Hazarika; Tarun K. Maji

2013-08-26T23:59:59.000Z

362

Kinetics of Ni Sorption in Soils: Roles of Soil Organic Matter and Ni Precipitation  

E-Print Network (OSTI)

Kinetics of Ni Sorption in Soils: Roles of Soil Organic Matter and Ni Precipitation Zhenqing Shi, Lawrence, Kansas 66045-7609, United States *S Supporting Information ABSTRACT: The kinetics of Ni sorption) precipitates using both experimental studies and kinetic modeling. Batch sorption kinetic experiments were

Sparks, Donald L.

363

Z. B. He et al., Nickel catalyst shape Etchant-induced shaping of nanoparticle  

E-Print Network (OSTI)

Z. B. He et al., Nickel catalyst shape - 1 - Etchant-induced shaping of nanoparticle catalysts al., Nickel catalyst shape - 2 - Abstract Carbon nanofibres (CNFs) obtained by plasma show in this paper that the shape of Ni nanoparticle catalysts, and in turn the CNF properties, can

Boyer, Edmond

364

Effect of laser irradiation on failure mechanism of TiCp reinforced titanium composite coating produced by laser cladding  

Science Journals Connector (OSTI)

Abstract Laser cladding is an effective technique to coat a metallic substrate with a layer of a different nature. It has been widely reported that the most important combined parameters controlling the quality of the coating are the specific energy (E) and the powder density (?). In the present work, clad deposits of Ti6Al4V + 60 wt.% TiC were prepared on a Ti6Al4V substrate using an optimum combination of Ec = 24 J/mm2 and ?c = 3 mg/mm2. These experiments were performed using a laser power of 400 and 600 W, in order to study the effect of laser power on the properties of the clad. The microstructure, phase composition and nanohardness of the coatings were investigated by optical microscopy, scanning electron microscopy and X-ray diffraction. During laser processing, TiC can be partially converted to TiCX (X = 0.5) due mainly to the TiC dissolution into the laser-generated melting pool and subsequent precipitation during cooling. It was observed that the lower laser power limit reduces primary TiC dissolution but it also promotes secondary carbide alignment at the interface. On the other hand, the damage mechanism induced by high laser power is dominated by primary TiC particle cracking by the high stress concentration at the particle–matrix interface followed by ductile failure of the matrix. It is also remarkable that irradiance affects the TiC/TiCx ratio despite Ec and ?c are fixed and it determines hardness distribution inside the coating.

J.J. Candel; J.A. Jimenez; P. Franconetti; V. Amigó

2014-01-01T23:59:59.000Z

365

Bond formation at the Ni/ZrO2 interface  

Science Journals Connector (OSTI)

We report on the formation of strong chemical bonds at the Ni(100)/cubic-ZrO2(100) polar interfaces. Ab initio density functional theory calculations demonstrate that both Zr/Ni and O/Ni junctions are energetically stable, and predict that two different interactions determine the interface adhesion. Our results reveal that O-Ni ionic bonds are formed by Ni electron donation, while the Zr-Ni bonds show a mixed character with ionic and electron hybridization contributions.

J. I. Beltrán; S. Gallego; J. Cerdá; J. S. Moya; M. C. Muñoz

2003-08-07T23:59:59.000Z

366

Positron-annihilation measurements of vacancy formation in Ni and Ni(Ge)  

SciTech Connect

Vacancy formation in Ni and in dilute Ni(Ge) alloys was studied under thermal equilibrium conditions using positron-annihilation Doppler broadening. A monovacancy formation enthalpy of 1.8 +- 0.1 eV was determined for pure Ni; combining this result with that from previous tracer self-diffusion measurements, a monovacancy migration enthalpy of 1.1 +- 0.1 eV was also deduced. Analysis of the vacancy formation measurements in Ni(0.3 at.% Ge) and Ni(1 at.% Ge) yielded a value for the vacancy-Ge binding enthalpy of 0.20 +- 0.04 eV.

Smedskjaer, L.C.; Fluss, M.J.; Legnini, D.G.; Chason, M.K.; Siegel, R.W.

1982-03-01T23:59:59.000Z

367

They Came From the Deep in the Supernova: The Origin of TiC and Metal Subgrains in Presolar Graphite Grains  

E-Print Network (OSTI)

A new formation scenario for TiC and Fe,Ni-metal inclusions in presolar graphite grains of supernova origin is described. The mineralogy and chemistry require condensation of (Fe,Ni)-titanides from Fe, Ni, and Ti-rich gaseous ejecta, subsequent carburization to make TiC and metal, and encapsulation into graphite. Titanides only condense if Si is depleted relative to heavier mass elements, which requires alpha-rich freeze-out and a deep mass-cut for the supernova ejecta. This Si-poor core material must remain unmixed with other supernova zones until the titanides condensed. This can be accomplished by transport of core ejecta in bipolar jets through the major expanding supernova zone ejecta. If the jets stall in regions dominated by C-rich ejecta such as C-He zone where graphite condenses, thermochemically favored in situ carburization of the titanides - either before or during encapsulation into condensing graphite - leads to a TiC and metal composite. This scenario agrees with theoretical models and observations of asymmetric core collapse in supernovae that are associated with bipolar jets loaded with iron-peak elements.

Katharina Lodders

2006-06-27T23:59:59.000Z

368

Photocatalytic Degradation of VOC's by TOTO's Hydrotect (TiO2 Impregnated) Surfaces  

E-Print Network (OSTI)

, naturally occurs in wood and volcanic gases. Decaying organic matter can also produce methanol. Paint. This report describes the photocatalytic degradation of formaldehyde and methanol, two common VOC's, by TiO2 and methanol tests (Land et al., 2008). A standardized aqueous solution of formaldehyde and methanol was used

Bergin, Mike

369

Quantum confinement induced magnetism in LaNiO3-LaMnO3 superlattices  

SciTech Connect

The emergence of magnetic reconstructions at the interfaces of oxide heterostructures are often explained via subtle modifications in the electronic densities, exchange couplings, or strain. Here, an additional possible route for induced magnetism is studied in the context of the (LaNiO3)n/(LaMnO3)n superlattices using a hybrid tightbinding model. In the LaNiO3 region, the induced magnetizations decouple from the intensity of charge leakage from Mn to Ni, but originate from the spin-filtered quantum confinement present in these nanostructures. In general, the induced magnetization is the largest for the (111)-stacking and the weakest for the (001)-stacking superlattices; results compatible with the exchange bias effects reported byGibert et al. [Nat.Mater. 11, 195 (2012)].

Dong, Shuai [ORNL; Dagotto, Elbio R [ORNL

2013-01-01T23:59:59.000Z

370

Purification and Characterization of [NiFe]-Hydrogenase of Shewanella...  

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

Purification and Characterization of NiFe-Hydrogenase of Shewanella oneidensis MR-1. Purification and Characterization of NiFe-Hydrogenase of Shewanella oneidensis MR-1....

371

A feasibility study of preparing MCrAlX/BN composite coatings by electrospark deposition process  

Science Journals Connector (OSTI)

MCrAlX/BN composite coatings have been attempted to prepare by electrospark deposition (ESD). The effects of different contents of BN addition (0 wt.%, 1 wt.%, 3 wt.% and 5 wt.%) on the microstructure and hardness of the coatings were presented. The results showed that, with increasing BN contents, the phase composition of the coatings changed from single ?-Ni(Co,Cr) to complex ?-Ni(Co,Cr), (Ni,Co)3B, CrB, TaB2 multi-phases. The microstructure morphology changed from cellular columnar to equiaxed dendrite. The average microhardness of the coatings increased from 450 HV to 850 HV.

Yu-jiang Xie; Mao-cai Wang

2009-01-01T23:59:59.000Z

372

ALS Chemistry Lab  

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

ALS Chemistry Lab Print ALS Chemistry Labs The ALS Chemistry Labs are located in the User Support Building (15-130) and in Building 6 (6-2233)*. These spaces are dedicated for...

373

ALS Chemistry Lab  

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

Safety Safety for Users ALS Chemistry Lab Print ALS Chemistry Labs The ALS Chemistry Labs are located in the User Support Building (15-130) and in Building 6 (6-2233)*. These...

374

Stoichiometry-driven metal-to-insulator transition in NdTiO{sub 3}/SrTiO{sub 3} heterostructures  

SciTech Connect

By controlling stoichiometry via a hybrid molecular beam epitaxy approach, we report on the study of thin film growth and the electronic transport properties of phase-pure, epitaxial NdTiO{sub 3}/SrTiO{sub 3} heterostructures grown on (001) (La{sub 0.3}Sr{sub 0.7})(Al{sub 0.65}Ta{sub 0.35})O{sub 3} (LSAT) substrates as a function of cation stoichiometry in NdTiO{sub 3}. Despite the symmetry mismatch between bulk NdTiO{sub 3} and the substrate, NdTiO{sub 3} films grew in an atomic layer-by-layer fashion over a range of cation stoichiometry; however amorphous films resulted in cases of extreme cation non-stoichiometry. Temperature-dependent sheet resistance measurements were consistent with Fermi-liquid metallic behavior over a wide temperature range, but revealed a remarkable crossover from metal-to-insulator (M-I) type behavior at low temperatures for all compositions. A direct correlation between cation stoichiometry, transport behavior, and the temperature of M-I transition is established.

Xu, Peng; Phelan, Daniel; Seok Jeong, Jong; Andre Mkhoyan, K.; Jalan, Bharat, E-mail: bjalan@umn.edu [Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

2014-02-24T23:59:59.000Z

375

Superior Corrosion Resistance Properties of TiN-Based Coatings on Zircaloy Tubes in Supercritical Water  

SciTech Connect

Thin films of TiN and Ti0.35Al0.65N nanocomposite were deposited on polished Zircaloy-4 tubes. After exposure to supercritical water for 48 h, the coated tubes are remarkably intact, while the bare uncoated tube shows severe oxidation and breakaway corrosion. X-ray diffraction patterns, secondary electron images, backscattered electron images, and energy dispersive X-ray spectroscopy data from the tube surfaces and cross-sections show that a protective oxide, formed on the film surface, effectively prevents further oxidation and corrosion to the Zircaloy-4 tubes. This result demonstrates the effectiveness of thin film ceramics as protective coatings under extreme environments.

Fauzia Khatkhatay; Liang Jiao; Jie Jian; Zhijie Jiao; Hongbin Zhang; Jian Gan; Haiyan Wang; Wenrui Zhang; Xinghang Zhang

2014-08-01T23:59:59.000Z

376

Oxygen Reduction Catalyzed by Au–TiO2 Nanocomposites in Alkaline Media  

Science Journals Connector (OSTI)

Au?TiO2 nanocomposite; oxygen reduction; alkaline media; RRDE; Tafel plot ... In another study, Kim et al.(14) prepared titanium oxide by heat treatment of titanium sheets in the temperature range of 600–1000 °C, and the best catalysts were identified as those prepared at 900 °C where ORR occurred at the potential of about +0.65 V versus RHE in 0.1 M H2SO4. ... In a typical measurement, 1 mg of the Au–TiO2 nanocomposite catalysts, 4 mg of carbon powder, and 10 ?L of Nafion were ultrasonically mixed in 1 mL of methanol. ...

Chan Lin; Yang Song; Lixin Cao; Shaowei Chen

2013-11-11T23:59:59.000Z

377

Ann bay lodyans 12 / Se Bryant Freeman ("Tonton Liben") ki pare ti liv sa a  

E-Print Network (OSTI)

a, Bondye fe yon bon ti melanj: li pran bwode ki gen nan pan, di ki gen nan woch, fines ki gen nan ke zwazo, douse ki gen nan siwo myel, mechanste ki gen nan tig, chale ki gen nan dife, fredi ki gen nan lanej. Bondye kontwole yo, sa pa ase.... Yo te viv ansanm pandan kek tan konsa. Men yon jou, msye a al devan Bondye ansanm ak fi a. Li pote I remet Bondye. Li di konsa: "Bondye, m pa kapab viv ak zanmi ou ban mwen an. Li pale san rete, li fatige m twop, menm yon ti poze m pa kab fe. Sa...

Freeman, Bryant C.

2000-01-01T23:59:59.000Z

378

Observation of TiH5 and TiH7 in Bulk-Phase TiH3 Gels for Kubas-Type Hydrogen Storage  

Science Journals Connector (OSTI)

Observation of TiH5 and TiH7 in Bulk-Phase TiH3 Gels for Kubas-Type Hydrogen Storage ... Table T2 provides the formulas and C, H, and Ti percentages of the hydrogenated materials in addition to those of representative stoichiometric compounds, including pure TiH3 and the starting material. ... In the TiH3 structure, the hydride ligands are a lightweight structural feature as opposed to a source of stored hydrogen, and additional hydrogen can bind via the Kubas interaction to access TiH5 and TiH7 species. ...

Tuan K. A. Hoang; Leah Morris; Daniel Reed; David Book; Michel L. Trudeau; David M. Antonelli

2013-11-14T23:59:59.000Z

379

Electroslag surfacing of steel shafting with Ni alloy 625 and 70Cu-30Ni strip  

SciTech Connect

A comprehensive study of electroslag surfacing (ESS) of steel with Ni Alloy 625 and 70Cu-30Ni strip electrodes was conducted to establish the feasibility of replacing forged bearing sleeves on propulsion shafting with integral weld surfacing. The base material was MIL-S-23284, Class 1 steel in the form of 41--66 cm (16--26 in.) diameter shafting and 76 mm (3 in.) thick flat plate. All ESS was carried out at a heat input level of approximately 5.9kJ/mm (150 kJ/in.) using 30 x 0.5 mm (1.2 x 0.02 in.) strip electrodes. Assessments of mechanical properties and microstructure of Ni Alloy 625 surfacing and 70Cu-30Ni surfacing were conducted to establish the structure-property relationships in these complex alloy systems. In addition, a solidification cracking test was developed to determine the relative cracking susceptibilities of these strip surfacing alloys. Although the Ni Alloy 625 surfacing contained small islands of interdendritic MC type carbides and Laves phase, the mechanical properties of this surfacing were satisfactory. The 70Cu-30Ni surfacing required a buttering layer of 30Cu-70Ni or pure Ni to prevent solidification cracking. The inherent ductility-dip sensitivity of 70Cu-30Ni surfacing was overcome by the development of a suitable ESS procedure.

Devletian, J.H.; Gao, Y.P.; Wood, W.E. [Oregon Graduate Inst. of Science and Technology, Portland, OR (United States)

1996-12-31T23:59:59.000Z

380

Induction of Cytotoxicity by Photoexcited TiO2 Particles  

Science Journals Connector (OSTI)

...TiO2 in the suspension was measured with combustion analysis. The TiO2 aqueous suspension...photoexcited TiO2 particles. it did not produce heat at the irradiated site. Since TiO2 alone...Heterogeneous photocatalytic oxidation of hydrocarbons on platinized TiO2 powders. J. Phys...

Ruxiong Cai; Yoshinobu Kubota; Taro Shuin; Hideki Sakai; Kazuhito Hashimoto; and Akira Fujishima

1992-04-15T23:59:59.000Z

Note: This page contains sample records for the topic "ni ti al" 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

New Ni Amidinate Source for ALD/CVD of NiNx, NiO and NiSi , Thiloma Perera1  

E-Print Network (OSTI)

to be particularly important in memory as well as logic applications. Nickel silicide (NiSi) is emerging with a metal-insulator-metal (MIM) structure, offer potential applications for the next generation nonvolatile

382

The thermomechanical constitutive experimentation of NiTi shape memory alloy strips and rods  

E-Print Network (OSTI)

exothermic reactions. During an exothermic reaction, the heat supplied is decreased to maintain the cooling temperature rate. The exothermic reactions are represented as power valleys on the DSC therinogram. The first exothermic transformations is caused... as the R-phase transforms from parent phase. As the sample continues to cool, the rhombohedral lattice transitions into monoclinic martensite. Thermal cycling and two way training can separate the R-phase and martensite exothermic transformation peaks...

Howard, Stephen David

1995-01-01T23:59:59.000Z

383

Demonstration of high efficiency elastocaloric cooling with large ?T using NiTi wires  

Science Journals Connector (OSTI)

Vapor compression (VC) is by far the most dominant technology for meeting all cooling and refrigeration needs around the world. It is a mature technology with the efficiency of modern compressors approaching the theoretical limit but its environmental footprint remains a global problem. VC refrigerants such as hydrochloroflurocarbons (HCFCs) and hydrofluorocarbons (HFCs) are a significant source of green house gas emissions and their global warming potential (GWP) is as high as 1000 times that of CO2 [Buildings Energy Data Book (Building Technologies Program Department of Energy 2009)]. There is an urgent need to develop an alternative high-efficiency cooling technology that is affordable and environmentally friendly [A. D. Little Report For Office of Building Technology State and Community Programs Department of Energy 2001]. Here we demonstrate that elastocaloric cooling (EC) a type of solid-state cooling mechanism based on the latent heat of reversible martensitic transformation can have the coefficient of performance as high as ?11 with a directly measured ?T of 17?°C. The solid-state refrigerant of EC completely eliminates the use of any GWP refrigerants including HCFCs/HFCs.

Jun Cui; Yiming Wu; Jan Muehlbauer; Yunho Hwang; Reinhard Radermacher; Sean Fackler; Manfred Wuttig; Ichiro Takeuchi

2012-01-01T23:59:59.000Z

384

Transformation Cyclic Damage of Near-equiatomic Ni-Ti Yinong Liu1,a  

E-Print Network (OSTI)

distortion. Cycling through this transformation, induced thermally, mechanically or by the combination, shape memory alloys, pseudoelasticity, mechanical behaviour, pseudoelasticity, thermal cycling Abstract. This study investigates the effect of transformation cycling and heat treatment on the property stability

Zheng, Yufeng

385

Formability of thermally cured and of nanoclay-reinforced polyelectrolyte films on NiTi substrates  

Science Journals Connector (OSTI)

The present study characterizes the formability of thin polyelectrolyte films which were modified by curing and alternatively reinforced with nano-sized clay-platelets. To investigate the suitability of modified ...

J. Lackmann; T. Niendorf; M. Maxisch; R. Regenspurger…

2012-01-01T23:59:59.000Z

386

Automation of Electrospark Deposition of TiCp/Ni on RSW Copper Electrodes.  

E-Print Network (OSTI)

??Electrospark Deposition (ESD) is a specialized micro-bonding process which is used to coat a base material, known as the substrate, with a stronger, tougher, and… (more)

Syed, Murtasim

2010-01-01T23:59:59.000Z

387

Thermomechanical Characterization of a TiPdNi High Temperature SMA under Tension  

E-Print Network (OSTI)

Electrode Discharge Machining (EDM). A high temperature experimental setup was developed on a load frame

388

Composition–Structure–Function Diagrams of Ti–Ni–Au Thin Film Shape Memory Alloys  

Science Journals Connector (OSTI)

thin films; annealing; high temperature shape memory alloys; combinatorial materials science; phase transformation ...

Pio John S. Buenconsejo; Alfred Ludwig

2014-11-04T23:59:59.000Z

389

NbTiN Based SIS Multilayer Structures for SRF Applications  

SciTech Connect

For the past three decades, bulk niobium has been the material of choice for SRF cavities applications. RF cavity performance is now approaching the theoretical limit for bulk niobium. For further improvement of RF cavity performance for future accelerator projects, Superconductor ? Insulator - Superconductor (SIS) multilayer structures (as recently proposed by Alex Gurevich) present the theoretical prospect to reach RF performance beyond bulk Nb, using thinly layered higher-Tc superconductors with enhanced Hc1. Jefferson Lab (JLab) is pursuing this approach with the development of NbTiN and AlN based multilayer SIS structures. This paper presents the results on the characteristics of NbTiN films and the first RF measurements on NbTiN-based multilayer structure on thick Nb films.

Valente, Anne-marie; Eremeev, Grigory; Phillips, H.; Reece, Charles; Spradlin, Joshua; Yang, Qiguang; Lukaszew, Rosa

2013-09-01T23:59:59.000Z

390

Pulsed electrospark deposition of MAX phase Cr2AlC based coatings on titanium alloy  

Science Journals Connector (OSTI)

Abstract Coatings with a high amount of MAX phase were obtained onto Ti substrate using the pulsed electrospark deposition (PED) technique and Cr2AlC electrode material (??). The structure and phase formation of the coatings generated at different modes were studied. It was found, that a layer of titanium carbide was formed during the initial stage of the deposition at the interface as a result of chemical reaction between Cr2AlC electrode and Ti substrate which further acts as a diffusion barrier.

E.I. Zamulaeva; E.A. Levashov; T.A. Sviridova; N.V. Shvyndina; M.I. Petrzhik

2013-01-01T23:59:59.000Z

391

Electron-Transport Properties of Amorphous (Zr0.64ni0.36)1-Xalx Alloys  

E-Print Network (OSTI)

-4242 (Received 28 November 1988; revised manuscript received 16 March 1989) Measurements of the electrical resistivity p(T), thermopower S(T), and Hall coe%cient RH for a series of rapidly quenched Zr-Ni-Al alloys are reported for concentrations from x =0 to 0...-metal or ?metalloid amorphous alloys, the sign of RH can change from positive to negative as the concentration of the early transition metal is decreased. This is particular- ly well illustrated by measurements on amorphous Zr- based alloys, Zr-Cu, ' ' Zr-Ni, ' Zr...

BHATNAGAR, AK; PAN, R.; Naugle, Donald G.

1989-01-01T23:59:59.000Z

392

Size effects in Ni/Ni(OH)2 nanomaterials for electrochemical capacitors.  

SciTech Connect

Electrochemical capacitors based on redox-active metal oxides show great promise for many energy-storage applications. These materials store charge through both electric double-layer charging and faradaic reactions in the oxide. The dimensions of the oxide nanomaterials have a strong influence on the performance of such capacitors. Not just due to surface area effects, which influence the double-layer capacitance, but also through bulk electrical and ionic conductivities. Ni(OH)2 is a prime candidate for such applications, due to low cost and high theoretical capacity. We have examined the relationship between diameter and capacity for Ni/Ni(OH)2 nanorods. Specific capacitances of up to 511 F/g of Ni were recorded in 47 nm diameter Ni(OH)2 nanorods.

Bunker, Bruce Conrad; Limmer, Steven J.; Yelton, William Graham

2010-04-01T23:59:59.000Z

393

Oxygen-Release-Related Thermal Stability and Decomposition Pathways of LixNi0.5Mn1.5O4 Cathode Materials  

Science Journals Connector (OSTI)

(21, 22) Therefore, LixMn2O4 has been regarded as a thermally safer cathode material than layered materials, such as LixCoO2, LixNi0.8Co0.15Al0.05O2, and LixNi1/3Co1/3Mn1/3O2. ... The d- and o-LNMO cathodes were fabricated by slurry-casting 80% active material, 10% of carbon black (Chevron), and 10% of PVDF (Kureha) onto an Al foil current collector. ...

Enyuan Hu; Seong-Min Bak; Jue Liu; Xiqian Yu; Yongning Zhou; Steven N. Ehrlich; Xiao-Qing Yang; Kyung-Wan Nam

2013-12-10T23:59:59.000Z

394

Highly uniform bipolar resistive switching characteristics in TiO{sub 2}/BaTiO{sub 3}/TiO{sub 2} multilayer  

SciTech Connect

Nanoscale multilayer structure TiO{sub 2}/BaTiO{sub 3}/TiO{sub 2} has been fabricated on Pt/Ti/SiO{sub 2}/Si substrate by chemical solution deposition method. Highly uniform bipolar resistive switching (BRS) characteristics have been observed in Pt/TiO{sub 2}/BaTiO{sub 3}/TiO{sub 2}/Pt cells. Analysis of the current-voltage relationship demonstrates that the space-charge-limited current conduction controlled by the localized oxygen vacancies should be important to the resistive switching behavior. X-ray photoelectron spectroscopy results indicated that oxygen vacancies in TiO{sub 2} play a crucial role in the resistive switching phenomenon and the introduced TiO{sub 2}/BaTiO{sub 3} interfaces result in the high uniformity of bipolar resistive switching characteristics.

Ma, W. J.; Zhang, X. Y.; Wang, Ying; Zheng, Yue, E-mail: zhengy35@mail.sysu.edu.cn, E-mail: wangbiao@mail.sysu.edu.cn [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-Sen University, 510275 Guangzhou (China) [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-Sen University, 510275 Guangzhou (China); Micro and Nano Physics and Mechanics Research Laboratory, School of Physics and Engineering, Sun Yat-Sen University, 510275 Guangzhou (China); Lin, S. P. [Micro and Nano Physics and Mechanics Research Laboratory, School of Physics and Engineering, Sun Yat-Sen University, 510275 Guangzhou (China) [Micro and Nano Physics and Mechanics Research Laboratory, School of Physics and Engineering, Sun Yat-Sen University, 510275 Guangzhou (China); Sino-French Institute of Nuclear Engineering and Technology, Zhuhai Campus, Sun Yat-Sen University, Zhuhai 519082 (China); Luo, J. M.; Wang, B., E-mail: zhengy35@mail.sysu.edu.cn, E-mail: wangbiao@mail.sysu.edu.cn [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-Sen University, 510275 Guangzhou (China); Li, Z. X. [Micro and Nano Physics and Mechanics Research Laboratory, School of Physics and Engineering, Sun Yat-Sen University, 510275 Guangzhou (China)] [Micro and Nano Physics and Mechanics Research Laboratory, School of Physics and Engineering, Sun Yat-Sen University, 510275 Guangzhou (China)

2013-12-23T23:59:59.000Z

395

ALS Chemistry Lab  

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

Chemistry Lab Print ALS Chemistry Labs The ALS Chemistry Labs are located in the User Support Building (15-130) and in Building 6 (6-2233)*. These spaces are dedicated for...

396

? decay of 40Ti and 41Ti and implication for solar-neutrino detection  

Science Journals Connector (OSTI)

The ? decay of 40Ti and 41Ti was studied by measuring the ?-delayed proton and ? emission. The half-lives for 40Ti and 41Ti were determined to be 54(2) and 82(3) ms, respectively. The experimental ?-decay strengths are compared with shell-model calculations and results from other measurements. The integrated Gamow-Teller strengths for 40Ti and 41Ti were found to be quenched, compared to the calculations, by factors of 0.79(3) and 0.93(3), respectively. Based on the experimental 40Ti??-decay strength, the neutrino absorption cross section and induced neutrino event rates for 40Ar were determined to be 14.3(3)×10-43?cm2 and 9.4±0.2(stat)-1.6+1.3(syst) SNU, respectively.

W. Liu; M. Hellström; R. Collatz; J. Benlliure; L. Chulkov; D. Cortina Gil; F. Farget; H. Grawe; Z. Hu; N. Iwasa; M. Pfützner; A. Piechaczek; R. Raabe; I. Reusen; E. Roeckl; G. Vancraeynest; A. Wöhr

1998-11-01T23:59:59.000Z

397

Patterned Growth of TiO2 Nanowires on Titanium Substrates Jong-Yoon Ha1;2  

E-Print Network (OSTI)

and short processing time utilizes the Ti foil both as a substrate and as a metal supply, thus eliminating transport methods. Adachi et al. have reported the synthesis of titania NWs using hydrothermal reactions, these methods typically require complex setups and processes, harsh environmental conditions, and extended

Lin, Liwei

398

Characteristics of vanadia on the surface of V2O5/Ti-PILC catalyst for the reduction of \\{NOx\\} by NH3  

Science Journals Connector (OSTI)

A series of vanadia catalysts impregnated on titania pillared interlayered clays (Ti-PILCs) were prepared to identify the characteristics of vanadia on the surface of Ti-PILC for the selective catalytic reduction (SCR) of NO by NH3. V2O5/Ti-PILC exhibited superior performance as a novel SCR catalyst compared to conventional catalysts including V2O5/TiO2 and V2O5/Al2O3. NO removal activity over the supported vanadia catalyst is strongly influenced by the structure of vanadia species on the catalyst surface. The structure of vanadia species on various supports including TiO2, Al2O3, and SiO2 along with Ti-PILC has been examined by XRD, NMR and Raman analyses for the comparative study. Increasing the content of vanadia up to the monolayer coverage of the surface of Ti-PILC catalyst enhanced the ratio of the polymerized surface vanadia species to the isolated ones. These results are well correlated with TOF of vanadia on the catalyst surface for the reduction of NO by NH3.

Ho Jeong Chae; In-Sik Nam; Sung-Won Ham; Suk Bong Hong

2004-01-01T23:59:59.000Z

399

Airtricity Developments NI Ltd | Open Energy Information  

Open Energy Info (EERE)

NI Ltd NI Ltd Jump to: navigation, search Name Airtricity Developments NI Ltd Place Belfast, Northern Ireland, United Kingdom Zip BT2 7AF Sector Wind energy Product Focused on construction of wind farms in Northern Ireland. Coordinates 54.595295°, -5.934524° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":54.595295,"lon":-5.934524,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

400

Magnetic quantum diesel engine in Ni2  

Science Journals Connector (OSTI)

Quantum Diesel cycles are numerically realized using the electronic states of a Ni2 dimer. The quantum nature and the complexity of the electronic structure of the Ni2 dimer result in new features in the evolution of the pressure as well as in the heat-work transformation. The multitude of internal degrees of freedom in the isobaric process in molecules can result in crossing of the two adiabatic processes in the P-V diagram. The interplay of heat and work, originating from thermal nonequilibrium effects, can lead to a thermal efficiency of up to 100%. The spin moment of the Ni2 can be decreased by the isobaric process. To link the molecular heat capacity to easily accessible experimental quantities, we also calculate the Kerr effect and the magnetic susceptibility at different temperatures and magnetic fields.

C. D. Dong; G. Lefkidis; W. Hübner

2013-12-20T23:59:59.000Z

Note: This page contains sample records for the topic "ni ti al" 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

Energy absorption in Ni-Mn-Ga/ polymer composites  

E-Print Network (OSTI)

In recent years Ni-Mn-Ga has attracted considerable attention as a new kind of actuator material. Off-stoichiometric single crystals of Ni2MnGa can regularly exhibit 6% strain in tetragonal martensites and orthorhombic ...

Feuchtwanger, Jorge

2006-01-01T23:59:59.000Z

402

Carbon Nanotube Growth Using Ni Catalyst in Different Layouts  

E-Print Network (OSTI)

Vertically aligned carbon nanotubes have been grown using Ni as catalyst by plasma enhanced chemical vapor deposition system (PECVD) in various pre-patterned substrates. Ni was thermally evaporated on silicon substrates ...

Nguyen, H. Q.

403

Synthesis of superheavy element 120 via {sup 50}Ti+{sup A}Cf hot fusion reactions  

SciTech Connect

Synthesis of superheavy element 120 in terms of the {sup 50}Ti+{sup 249-252}Cf fusion-evaporation reactions is evaluated and discussed. It is found that the reactions of {sup 250,251}Cf({sup 50}Ti,3n){sup 297,298}120 and {sup 251,252}Cf({sup 50}Ti,4n){sup 297,298}120 are relatively favorable with the maximum evaporation-residue cross sections of 0.12, 0.09, 0.11, and 0.25 pb, respectively. However, {sup 252}Cf may be difficult to be target because its spontaneous fission will bring about serious background in the experiment. Fusion probabilities for different target-projectile combinations leading to the formation of surperheavy nucleus {sup 302}120 are estimated with the ''fusion-by-diffusion'' model and presented as a function of the Coulomb parameter Z{sub 1}Z{sub 2}/(A{sub 1}{sup 1/3}+A{sub 2}{sup 1/3}). Among the reactions {sup 50}Ti+{sup 252}Cf, {sup 54}Cr+{sup 248}Cm, {sup 58}Fe+{sup 244}Pu, and {sup 64}Ni+{sup 238}U, the reaction {sup 50}Ti+{sup 252}Cf has the largest fusion probability. Synthesis of superheavy element 120 is of essential importance for determining whether the magic proton shell should be at Z=114 or at higher proton numbers Z=120-126. Therefore, the experiment to produce isotopes with Z=120 in the fusion reactions {sup 50}Ti+{sup 250,251}Cf is of great interest.

Liu, Z. H. [China Institute of Atomic Energy, Beijing 102413 (China); Bao Jingdong [Department of Physics, Beijing Normal University, Beijing 100875 (China); Center of Theoretical Nuclear Physics, National Laboratory of Heavy Ion Accelerator, Lanzhou 730000 (China)

2009-11-15T23:59:59.000Z

404

Good and bad features of Ni-Cd cell designs  

SciTech Connect

Processes for spacecraft Ni-Cd cells are reviewed. Mechanical impregnation is compared against chemical and thermochemical impregnation.

Gross, S.

1996-02-01T23:59:59.000Z

405

Performance Degradation of TiN-and TiC-deposited AISI316 bipolar plates for proton exchange membrane fuel cells  

Science Journals Connector (OSTI)

TiN and TiC were deposited on AISI316 bipolar plates for proton exchange membrane fuel cells (PEMFCs) and their effects on the corrosion resistance and overall cell performance were investigated. TiN with a Ti...

Hee Yeol Lee; Jae Woong Choi; Gil Ho Hwang…

2006-04-01T23:59:59.000Z

406

Narrow band defect luminescence from Al-doped ZnO probed by scanning tunneling cathodoluminescence  

E-Print Network (OSTI)

Institute of Physics. Related Articles Effect of CdS film thickness on the photoexcited carrier lifetime of TiO2/CdS core-shell nanowires Appl. Phys. Lett. 99, 153111 (2011) Current underestimationNarrow band defect luminescence from Al-doped ZnO probed by scanning tunneling cathodoluminescence

Russell, Kasey

407

E-Print Network 3.0 - al2o3 fgm joints Sample Search Results  

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

5 . D-10587 Berlin Summary: to such kind of FGMs as: some ce- ramicceramic FGMs, i.e. TiCSiC, MoSi2Al2O3 and MoSi2SiC, and also some ce... the behavior of cracks in a graded...

408

Ann bay lodyans 1 / se Bryant Freeman ("Tonton Liben") ki pare ti liv sa a  

E-Print Network (OSTI)

Ian santi sa 11 ap manje a. Li pa menm di bonjou menm. Li di li konsa: "Granmoun, kote 2 pou m fe pou m al lakay Bondye?" Granmoun Ian we li malelve, li reponn: "Fe sa. Ou a twouve kay Bondye." Wout sa a mennen nan yon twou djab. Vwala, neg la... pou I rive lakay Bondye. Ti granmoun Ian di I menm bagay: "Fe sa." Msye a swiv menm wout la, e tchoup! Djab yo manje I menm jan. Le manman an pa we 2 pitit li yo, ke li sote. Tchikata, twazyem gason an, di: "Manman, kite m al we kote yo ye...

Freeman, Bryant C., ed.

2000-01-01T23:59:59.000Z

409

Geometric structures of thin film: Pt on Pd(110) and NiO on Ni(100)  

SciTech Connect

This thesis is divided into 3 papers: dynamical low-energy electron- diffraction investigation of lateral displacements in topmost layer of Pd(110); determination of (1{times}1) and (1{times}2) structures of Pt thin films on Pd(110) by dynamical low-energy electron-diffraction analysis; and structural determination of a NiO(111) film on Ni(100) by dynamical low-energy electron-diffraction analysis.

Warren, O.L.

1993-07-01T23:59:59.000Z

410

X-ray Absorption Measurements on Nickel Cathode of Sodium-beta Alumina batteries: Fe-Ni-CI Chemical Associations  

SciTech Connect

Sections of Na-Al-NiCl2 cathodes from sodium-beta alumina ZEBRA batteries have been characterized with X-ray fluorescence mapping, and XANES measurements to probe the microstructure, elemental correlation, and chemical speciation after voltage cycling. Cycling was performed under identical load conditions at either 240 or 280 °C operating temperature and subsequently quenched in either the charged or discharged state. X-ray fluorescence mapping and XANES measurements were made adjacent to the current collector and ?"-Al2O3 solid electrolyte interfaces to detect possible gradients in chemical properties across the cathode. An FeS additive, introduced during battery synthesis, was found to be present as either Fe metal or an Fe(II) chloride in all cathode samples. X-ray fluorescence mapping reveals an operating temperature and charge-state dependent spatial correlation between Fe, Ni, and Cl concentration. XANES measurements indicate that both Ni and Fe are chemically reactive and shift between metallic and chloride phases in the charged and discharged states, respectively. However the percentage of chemically active Ni and Fe is significantly less in the cell operated at lower temperature. Additionally, the cathode appeared chemically homogeneous at the scale of our X-ray measurements.

Bowden, Mark E.; Alvine, Kyle J.; Fulton, John L.; Lemmon, John P.; Lu, Xiaochuan; Webb-Robertson, Bobbie-Jo M.; Heald, Steve M.; Balasubramanian, Mahalingam; Mortensen, Devon R.; Seidler, Gerald T.; Hess, Nancy J.

2014-02-01T23:59:59.000Z

411

Corrosion resistance and friction of sintered NdFeB coated with Ti/TiN multilayers  

E-Print Network (OSTI)

Corrosion resistance and friction of sintered NdFeB coated with Ti/TiN multilayers Yuanyuan Cheng Polarization Fretting corrosion Ti/TiN multilayers were deposited on sintered NdFeB by radio frequency magnetron sputtering. The film grain size decreased with the number of multilayers in the stack. Corrosion

Volinsky, Alex A.

412

Science DMZ for ALS  

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

ALS Science Engagement Move your data Programs & Workshops Science Requirements Reviews Case Studies OSCARS Case Studies Science DMZ Case Studies Science DMZ @ UF Science DMZ @ CU...

413

Flüssiger Wasserstoff als Kraftstoff  

Science Journals Connector (OSTI)

Seit mehr als hundert Jahren stellen Kohlenwasserstoffe aus Rohöl fast ausschließlich die Basis für alle im Verkehr verwendeten Kraftstoffe dar. Ein Verkehr ohne Benutzung von Kraftstoffen auf Kohlenwasserstof...

Prof. Dr. Ing. habil. Walter Peschka

1984-01-01T23:59:59.000Z

414

Howes et al. Reply  

E-Print Network (OSTI)

Howes et al. Reply to Comment on "Kinetic Simulations of Magnetized Turbulence in Astrophysical Plasmas" arXiv:0711.4355

G. G. Howes; S. C. Cowley; W. Dorland; G. W. Hammett; E. Quataert; A. A. Schekochihin; T. Tatsuno

2008-12-12T23:59:59.000Z

415

Fabrication of TiO{sub 2} nanocrystallized glass  

SciTech Connect

Nanocrystallization of rutile and anatase was observed in a CaO-B{sub 2}O{sub 3}-Bi{sub 2}O{sub 3}-Al{sub 2}O{sub 3}-TiO{sub 2} crystallized glass. The color of the present crystallized glass was changed by the heat-treatment temperature, and x-ray diffraction (XRD) patterns of the crystallized glass show that the apparent color change is correlated with the formation of titania nanocrystallites. The particle size of crystallites observed in the transmission electron microscope image is comparable to that measured by XRD pattern. In addition, a large change of refractive index between the rutile particles and glass matrix, 0.8 or larger, was obtained. The present titania crystallized glass will be not only a photocatalytic material but also a promising candidate for random lasing devices.

Masai, Hirokazu; Fujiwara, Takumi; Mori, Hiroshi; Komatsu, Takayuki [Department of Applied Physics, Tohoku University, 6-6-05 Aoba, Sendai 980-8579 (Japan); Department of Materials Science and Technology, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka 940-2188 (Japan)

2007-02-19T23:59:59.000Z

416

Comparison of Three Ni-Hard I Alloys  

Office of Scientific and Technical Information (OSTI)

Comparison of Three Ni-Hard I Alloys Comparison of Three Ni-Hard I Alloys Ö. N. Do-an 1 , J.A. Hawk 1 , and J.Rice 2 1 U.S. Department of Energy, Albany Research Center, Albany, Oregon 2 Texaloy Foundry Co., Inc., Floresville, Texas Keywords: Ni-Hard white irons, Bainite, Martensite, Austenite, Abrasion resistant iron Abstract This report documents the results of an investigation which was undertaken to reveal the similarities and differences in the mechanical properties and microstructural characteristics of three Ni-Hard I alloys. One alloy (B1) is ASTM A532 class IA Ni-Hard containing 4.2 wt. pct. Ni. The second alloy (B2) is similar to B1 but higher in Cr, Si, and Mo. The third alloy (T1) also falls in the same ASTM specification, but it contains 3.3 wt. pct. Ni. The alloys were evaluated in both as-cast and

417

Calculator Tips for TI-30XA  

E-Print Network (OSTI)

TI-30XA Calculator Tips. Calculator Memory. - To use the memory function, hit the STO key to store a number in either memory 1, 2, or 3. o To store the product of ...

Owen Davis

2013-01-04T23:59:59.000Z

418

Science DMZ for ALS  

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

ALS ALS About ESnet Overview ESnet Staff Governance Our Network Case Studies OSCARS Case Studies Science DMZ Case Studies Science DMZ CU Science DMZ Penn State & VTTI Science DMZ NOAA Science DMZ NERSC Science DMZ ALS Multi-facility Workflow LCLS ESnet Strategic Plan ESnet Organizational Chart ESnet History Science Requirements Careers Contact Us Technical Assistance: 1 800-33-ESnet (Inside the US) 1 800-333-7638 (Inside the US) 1 510-486-7600 (Globally) 1 510-486-7607 (Globally) Report Network Problems: trouble@es.net Provide Web Site Feedback: info@es.net Science DMZ for ALS Many beamline scientists at Berkeley Lab's Advanced Light Source (ALS) are or will be experiencing slower network speeds because of instrument upgrades. These new instruments, or more specifically detectors, are

419

In-situ Spectroscopy of Water Oxidation at Ir Oxide Nanocluster Drivenby Visible TiOCr Charge-Transfer Chromophore in Mesoporous Silica  

SciTech Connect

An all-inorganic photocatalytic unit consisting of a binuclear TiOCr charge-transfer chromophore coupled to an Ir oxide nanocluster has been assembled on the pore surface of mesoporous silica AlMCM-41. In situ FT-Raman and EPR spectroscopy of an aqueous suspension of the resulting IrxOy-TiCr-AlMCM-41 powder reveal the formation of superoxide species when exciting the Ti(IV)OCr(III) --> Ti(III)OCr(IV) metal-to-metal charge-transfer chromophore with visible light. Use of H218O confirms that the superoxide species originates from oxidation of water. Photolysis in the absence of persulfate acceptor leads to accumulation of Ti(III) instead. The results are explained by photocatalytic oxidation of water at Ir oxide nanoclusters followed by trapping of the evolving O2 by transient Ti(III) centers to yield superoxide. Given the flexibility to select donor metals with appropriate redox potential, photocatalytic units consisting of a binuclear charge-transfer chromophore coupled to a water oxidation catalyst shown here constitute a step towards thermodynamically efficient visible light water oxidation units.

Frei, Heinz; Han, Hongxian; Frei, Heinz

2008-06-03T23:59:59.000Z

420

Structural and electrochemical characterization of lithium excess and Al-doped nickel oxides synthesized by the sol–gel method  

Science Journals Connector (OSTI)

The effects of excess lithium and aluminum doping in nickel oxide were investigated in an attempt to improve electrochemical properties of the layered LiNiO2. Li1+xNiO2 (x=0–0.02) and LiAlyNi1?yO2 (y=0–0.3) powders were synthesized by a sol–gel method using adipic acid as a chelating agent. The electrochemical properties of the synthesized materials were explored at room and high temperatures. Gas analysis during decomposition of gel precursors revealed that oxygen might play an important role in the synthesis of highly crystallized LiNiO2. Although the electrochemical test of the Al-doped samples showed a low initial discharge capacity of about 140 mAh g?1, the capacity loss with repeated cycling was very small at room temperature. Furthermore the fade in capacity of this cell at high temperature (50°C) was almost negligible. The Al-doping of the LiNiO2 cathode material was very effective in improving cycle performance at high temperature due to the enhanced stability of LiNiO2 structure.

Sang Ho Park; Ki Soo Park; Yang Kook Sun; Kee Suk Nahm; Yun Sung Lee; Masaki Yoshio

2001-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ni ti al" 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

SF 6432-NI (04-95)  

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

6/14/11 6/14/11 Page 1 of 14 Printed copies of this document are uncontrolled. Retrieve latest version electronically. SF 6432-NI (06/14/11) SECTION II STANDARD TERMS AND CONDITIONS FOR FIXED PRICE CONTRACTS WITH THE NEWLY INDEPENDENT STATES OF THE FORMER SOVIET UNION INDEX OF CLAUSES. THE FOLLOWING CLAUSES APPLY TO REQUESTS FOR QUOTATION AND CONTRACTS AS INDICATED UNLESS SPECIFICALLY DELETED, OR EXCEPT TO THE EXTENT THEY ARE SPECIFICALLY SUPPLEMENTED OR AMENDED IN WRITING IN THE SIGNATURE PAGE OR SECTION I. NI01 - ACCEPTANCE OF TERMS AND CONDITIONS Contractor, by signing this Agreement, beginning performance, and/or delivering Items or services ordered under this Agreement, agrees to comply with all the terms and conditions and all specifications and other documents that this Contract incorporated by

422

Microsoft Word - NiR.doc  

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Side-on Cu-Nitrosyl Coordination by Nitrite Reductase Side-on Cu-Nitrosyl Coordination by Nitrite Reductase Elitza I. Tocheva and Michael E. P. Murphy Department of Microbiology & Immunology, The University of British Columbia, Vancouver, BC, Canada V6T 1Z3. Nitric oxide (NO) is one of the smallest and simplest biologically active molecules. In mammals, NO is produced from arginine by isoforms of nitric oxide synthase, and it func- tions in signal transduction and as a cytoprotective or cytotoxic agent. In bacteria, NO is produced by nitrite reductase (NiR), a copper-containing enzyme, which is responsible for the reduction of nitrite to nitric oxide (NO) in the process of dissimilatory denitrification. Cu- containing NiRs are homotrimers with two distinct Cu sites per monomeric unit (1). The type

423

Magnetoelectric coupling tuned by competing single iron anisotropies in Mn1 xNixTiO3  

SciTech Connect

A flop of electric polarization from Pc to Pa is observed in MnTiO3 as a spin flop transtion is triggered by a c-axis magnetic field, Hc=7 T. The critical magnetic field for Pa is significantly reduced in Mn1 xNixTiO3 (x=0.33). Neutron diffraction measurements revealed similar magnetic arrangements for the two compositions where the ordered spins couple antiferromagnetically with their nearest intra- and inter-planar neighbors. In the x=0.33 system, the single ion anisotropies of Mn2+ and Ni2+ compete and give rise to an additional spin reorientation transition at TR. A magnetic field, Hc, aligns the spins along c for TRNi content increases to x=0.5 and 0.68, the ME effect disappears as a new magnetic phase emerges.

Chi, Songxue [ORNL; Ye, Feng [ORNL; Zhou, Haidong [ORNL; Choi, E. S. [National High Magnetic Field Laboratory (Magnet Lab), Florida; Cao, Huibo [ORNL; Hwang, J. [National High Magnetic Field Laboratory (Magnet Lab), Florida; Fernandez-Baca, Jaime A [ORNL; Hwang, J [Florida State University, Tallahassee

2014-01-01T23:59:59.000Z

424

Comparative investigation on chemical looping combustion of coal-derived synthesis gas containing H2S over supported NiO oxygen carriers  

SciTech Connect

Chemical looping combustion (CLC) of simulated coal-derived synthesis gas was conducted with NiO oxygen carriers supported on SiO2, ZrO2, TiO2, and sepiolite. The effect of H2S on the performance of these samples for the CLC process was also evaluated. Five-cycle thermogravimetric analysis (TGA) tests at 800 #1;C indicated that all oxygen carriers had a stable performance at 800 #1;C, except NiO/SiO2. Full reduction/oxidation reactions of the oxygen carrier were obtained during the five-cycle test. It was found that support had a significant effect on reaction performance of NiO both in reduction and oxidation rates. The reduction reaction was significantly faster than the oxidation reaction for all oxygen carriers, while the oxidation reaction is fairly slow due to oxygen diffusion on NiO layers. The reaction profile was greatly affected by the presence of H2S, but there was no effect on the capacity due to the presence of H2S in synthesis gas. The presence of H2S decreased reduction reaction rates significantly, but oxidation rates of reduced samples increased. X-ray diffraction (XRD) data of the oxidized samples after a five-cycle test showed stable crystalline phases without any formation of sulfides or sulfites/sulfates. Increase in reaction temperature to 900 #1;C had a positive effect on the performance.

Ksepko, E.; Siriwardane, R.; Tian, H.; Simonyi, T.; Sciazko, M.

2010-01-01T23:59:59.000Z

425

High Energy Density Na-S/NiCl2 Hybrid Battery  

SciTech Connect

High temperature (250-350°C) sodium-beta alumina batteries (NBBs) are attractive energy storage devices for renewable energy integration and other grid related applications. Currently, two technologies are commercially available in NBBs, e.g., sodium-sulfur (Na-S) battery and sodium-metal halide (ZEBRA) batteries. In this study, we investigated the combination of these two chemistries with a mixed cathode. In particular, the cathode of the cell consisted of molten NaAlCl4 as a catholyte and a mixture of Ni, NaCl and Na2S as active materials. During cycling, two reversible plateaus were observed in cell voltage profiles, which matched electrochemical reactions for Na-S and Na-NiCl2 redox couples. An irreversible reaction between sulfur species and Ni was identified during initial charge at 280°C, which caused a decrease in cell capacity. The final products on discharge included Na2Sn with 1< n < 3, which differed from Na2S3 found in traditional Na-S battery. Reduction of sulfur in the mixed cathode led to an increase in overall energy density over ZEBRA batteries. Despite of the initial drop in cell capacity, the mixed cathode demonstrated relatively stable cycling with more than 95% of capacity retained over 60 cycles under 10mA/cm2. Optimization of the cathode may lead to further improvements in battery performance.

Lu, Xiaochuan; Lemmon, John P.; Kim, Jin Yong; Sprenkle, Vincent L.; Yang, Zhenguo (Gary) [Gary

2013-02-15T23:59:59.000Z

426

ALS Beamlines Directory  

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ALS Beamlines Directory Print ALS Beamlines Directory Print Beamlines, Parameters, Contact Information, and Schedules Download a high-resolution version of the ALS Beamclock. See Beamclock to view the ALS energy-related beamlines beamclock. Beamline Parameters Beamline and endstation technical information is available through the links below. Unless otherwise noted, all beamlines are currently operational. Individual beamline schedules are posted when available. Please contact the responsible beamline scientist for additional schedule information. When calling from off-site, all beamline (BL) phone numbers that begin with a "2" are preceded by 495- (i.e., 495-2014); all others are preceded by 486-. Beamline Number Source Technique/ Group Name Energy Range Beamline Contact Schedule/BL Phone

427

ALS Beamlines Directory  

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

ALS Beamlines Directory Print ALS Beamlines Directory Print Beamlines, Parameters, Contact Information, and Schedules Download a high-resolution version of the ALS Beamclock. See Beamclock to view the ALS energy-related beamlines beamclock. Beamline Parameters Beamline and endstation technical information is available through the links below. Unless otherwise noted, all beamlines are currently operational. Individual beamline schedules are posted when available. Please contact the responsible beamline scientist for additional schedule information. When calling from off-site, all beamline (BL) phone numbers that begin with a "2" are preceded by 495- (i.e., 495-2014); all others are preceded by 486-. Beamline Number Source Technique/ Group Name Energy Range Beamline Contact Schedule/BL Phone

428

ALS User Meeting Archives  

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ALS User Meeting Archives ALS User Meeting Archives Past User Meeting Agendas, Workshops, and Awards Year Agenda Workshops David A. Shirley (Science) Klaus Halbach (Instrumentation) Tim Renner (Service) 2012 2012 User Meeting Agenda 2012 User Meeting Workshops 2012 ALS User Meeting Awards Carl Percival, Dudley Shallcross, Craig Taatjes and David Osborn (Sandia), for making the first direct measurements of the reactions of Criegee intermediates, and showing that their impact on tropospheric chemistry and climate may be substantially greater than previously assumed. 2012 ALS User Meeting Awards Jeff Dickert and Simon Morton of Berkeley Lab's Physical Biosciences Division for the invention and implementation of the Compact Variable Collimator (CVC), which has led to a dramatic increase in productivity of protein crystallography.

429

Hacking als Grenzüberschreitung  

Science Journals Connector (OSTI)

In der Vergangenheit hat es sich als nützlich erwiesen, am Anfang eines Vortrages erst einmal ein paar Worte zu dem Verein zu verlieren, in dessen Vorstand ich mitwirke. Der Chaos Computer Club (CCC) ist viele...

Frank Simon

1994-01-01T23:59:59.000Z

430

ALS Staff Photo  

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Staff Photo Print On May 14, 2013, members of ALS staff posed for a group photo in front of the dome. A hi-res version can be downloaded here. The last staff photo was taken in...

431

Flachglas Als Baustoff  

Science Journals Connector (OSTI)

Der Werkstoff Glas bezeichnet ein Schmelzprodukt, das in der Natur als erstarrte vulkanische Schmelze vorkommt und dem Mensch bereits vor 5000 Jahren für die Herstellung von Schmuck und Werkstücken diente. Im ...

2007-01-01T23:59:59.000Z

432

Fast Transporting ZnO–TiO2 Coaxial Photoanodes for Dye-Sensitized Solar Cells Based on ALD-Modified SiO2 Aerogel Frameworks  

Science Journals Connector (OSTI)

To circumvent this problem, we have explored here the idea of conformally coating the silica–ZnO aerogel structures with very thin layers of more robust metal oxides such as Al2O3, ZrO2, or TiO2 to create doubly coaxial structures. ... J–V characteristics of DSSCs featuring 25 ?m thick aerogel-based SiO2–ZnO films compared to similar films with ca. 3 and 4 Å coatings of Al2O3 and TiO2, respectively: (a) light performance; (b) dark performance. ... Figure 7. Plot showing the effects of increased layers of TiO2 coats over 6 nm ZnO-coated silica aerogels with respect to charge lifetimes from OCVD measurements. ...

Vennesa O. Williams; Nak Cheon Jeong; Chaiya Prasittichai; Omar K. Farha; Michael J. Pellin; Joseph T. Hupp

2012-06-21T23:59:59.000Z

433

E-Print Network 3.0 - al-ni intermetallic compound Sample Search...  

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Therefore, it is key that these intermetallic compounds are identified... the solderconductor interface toward the inside of the IMC ... Source: Ekere, Ndy - School of...

434

E-Print Network 3.0 - aluminum nickelide ni3al Sample Search...  

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

been considered a viable material for templated growth... no investigation into how pore growth is affected by confining the pre-anodized aluminum dimensions... to the nanometer...

435

Extended solid solution and nonequilibrium phase diagram for Ni-Al alloy formed during laser cladding  

Science Journals Connector (OSTI)

Due to rapid solidification in laser cladding, the composition of the solute in the cladding alloy often exceeds the solid solubility limit ... various process parameters on the composition of the cladding alloy ...

A. Kar; J. Mazumder

1989-03-01T23:59:59.000Z

436

tude de nouveaux matriaux composites de type Si/Sn-Ni/Al/C pour lectrode  

E-Print Network (OSTI)

-AIME, Montpellier (Président) LRCS, Amiens (Rapporteur) ICGM-AIME, Montpellier (Rapporteur) SAFT, Bordeaux la Recherche de SAFT, pour leur suivi appréciable et pour leur accueil au sein de la société SAFT lieu sans le soutien financier du CNRS et SAFT-batteries. Je suis extrêmement honorée que M. Christian

Paris-Sud XI, Université de

437

Fusion of radioactive $^{132}$Sn with $^{64}$Ni  

E-Print Network (OSTI)

Evaporation residue and fission cross sections of radioactive $^{132}$Sn on $^{64}$Ni were measured near the Coulomb barrier. A large sub-barrier fusion enhancement was observed. Coupled-channel calculations including inelastic excitation of the projectile and target, and neutron transfer are in good agreement with the measured fusion excitation function. When the change in nuclear size and shift in barrier height are accounted for, there is no extra fusion enhancement in $^{132}$Sn+$^{64}$Ni with respect to stable Sn+$^{64}$Ni. A systematic comparison of evaporation residue cross sections for the fusion of even $^{112-124}$Sn and $^{132}$Sn with $^{64}$Ni is presented.

J. F. Liang; D. Shapira; J. R. Beene; C. J. Gross; R. L. Varner; A. Galindo-Uribarri; J. Gomez del Campo; P. A. Hausladen; P. E. Mueller; D. W. Stracener; H. Amro; J. J. Kolata; J. D. Bierman; A. L. Caraley; K. L. Jones; Y. Larochelle; W. Loveland; D. Peterson

2007-04-05T23:59:59.000Z

438

Computing Free Energy Landscapes: Application to Ni-based Electrocatal...  

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Computing Free Energy Landscapes: Application to Ni-based Electrocatalysts with Pendant Amines for H2 Production and Oxidation. Computing Free Energy Landscapes: Application to...

439

Structure, Magnetism and Conductivity in Epitaxial Ti-doped ...  

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Magnetism and Conductivity in Epitaxial Ti-doped -Fe2O3 Hematite: Experiment and density functional theory Structure, Magnetism and Conductivity in Epitaxial Ti-doped -Fe2O3...

440

Oxygen Vacancies and Ferromagnetism in CoxTi–x–y...  

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Vacancies and Ferromagnetism in CoxTi–x–y. Oxygen Vacancies and Ferromagnetism in CoxTi–x–y. Abstract: Abstract: Cobalt-doped titanium dioxide, or CTO, has...

Note: This page contains sample records for the topic "ni ti al" 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

Co-doped Anatase TiO? Heteroepitaxy on Si(001)  

SciTech Connect

Pure anatase TiO? and CoxTi?-x O? (0.01 < x < 0.04) epitaxial thin films were deposited by oxygen-plasma-assisted molecular beam epitaxy (OPA-MBE) on Si(001) for evaluation as a potential dilute magnetic semiconductor material suitable for Si-based spintronic devices. Epitaxial growth on Si(001) was facilitated by the deposition of ¼or ½ ML Sr metal on the clean Si(001) surface to form an oxidation resistant silicide layer, followed by deposition of a thin SrTiO? buffer layer. Using ½ ML Sr metal to form the silicide allowed the deposition of 10 ML SrTiO? without oxidation of the Si interface. Epitaxial anatase could be grown on this heterostructure, although use of the oxygen plasma during deposition resulted in significant SiO? formation. Pure anatase films consisted of epitaxial anatase surface particles on a continuous anatase film. For Co-doped films, Co segregation to surface particles of epitaxial anatase was observed by Auger electron spectroscopy and transmission electron microscopy (TEM); faceting of the particles was observed for low Co doping concentrations. Although no secondary phases containing Co were observed in Co-doped anatase films by x-ray diffraction or TEM, x-ray absorption near edge spectroscopy indicated Co was present in the films as a mixture of Co(0), Co(II), and Co(III). All samples were ferromagnetic at room temperature; for lower Co concentrations, the ferromagnetic remanence (9%) and coercive field (100 Oe) were similar to phase-pure Co:TiO? / LaAlO?. However, the presence of Co(0) under strongly oxidizing growth conditions known to oxidize the Si interface implies that under no deposition conditions can Co metal be eliminated while simultaneously protecting the Si interface from oxidation.

Kaspar, Tiffany C.; Droubay, Timothy C.; Wang, Chong M.; Heald, Steve M.; Lea, Alan S.; Chambers, Scott A.

2005-04-01T23:59:59.000Z

442

TiSol | Open Energy Information  

Open Energy Info (EERE)

TiSol TiSol Jump to: navigation, search Name TiSol Place Pasadena, California Sector Solar Product California-based start up focused on the production of dye sensitized solar cells. Coordinates 29.690847°, -95.196308° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":29.690847,"lon":-95.196308,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

443

Modelling Tools for the Efficient Design of New Alloys C J Humphreys and H K D H Bhadeshia  

E-Print Network (OSTI)

will revolutionise the way gas turbine (and other) materials are developed. A wide range of computer modelling stress, heat transfer, solidification, residual stress, creep, fatigue, lifetime, etc. In this paper we) Cluster variation method modelling of a potential new turbine disc material: NiTi/Ni2TiAl. (iii) Ab

Cambridge, University of

444

Morphology, deformation, and defect structures of TiCr{sub 2} in Ti-Cr alloys  

SciTech Connect

The morphologies and defect structures of TiCr{sub 2} in several Ti-Cr alloys have been examined by optical metallography, x-ray diffraction, and transmission electron microscopy (TEM), in order to explore the room-temperature deformability of the Laves phase TiCr{sub 2}. The morphology of the Laves phase was found to be dependent upon alloy composition and annealing temperature. Samples deformed by compression have also been studied using TEM. Comparisons of microstructures before and after deformation suggest an increase in twin, stacking fault, and dislocation density within the Laves phase, indicating some but not extensive room-temperature deformability.

Chen, K.C.; Allen, S.M.; Livingston, J.D.

1992-12-31T23:59:59.000Z

445

Synthesis of Ti-based electrodes using Ti-salt flocculated sludge and their application in lithium-ion batteries  

SciTech Connect

We report a simple strategy to synthesize the nanostructured TiO{sub 2} samples by a solid state reaction using Ti-salt flocculated sludge. The structure and morphology of the Ti-salt flocculated sludge, nanostructured TiO{sub 2} samples and pure commercial Aldrich TiO{sub 2} powder were characterized by powder X-ray diffraction and field emission scanning electron microscopy (FE-SEM). The electrochemical performances were evaluated in coin type cells. Nanostructured TiO{sub 2} samples, obtained by Ti-salt flocculated sludge shows a higher capacity and better cycling performances than pure commercial Aldrich TiO{sub 2} powder at the cutoff of 1.0–2.5 V especially at high current rate. The enhanced cycling performance can be attributed to the facts that their high crystallinity and uniform nano-sized distribution.

Kang, Jungwon; Rai, Alok Kumar; Kim, Sungjin; Choi, Eunseok; Yoo, Insun [Department of Materials Science and Engineering, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju 500-757 (Korea, Republic of)] [Department of Materials Science and Engineering, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju 500-757 (Korea, Republic of); Kim, Jongho [School of Applied Chemical Engineering and the Research Institute for Catalysis, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju 500-757 (Korea, Republic of)] [School of Applied Chemical Engineering and the Research Institute for Catalysis, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju 500-757 (Korea, Republic of); Kim, Jaekook, E-mail: jaekook@chonnam.ac.kr [Department of Materials Science and Engineering, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju 500-757 (Korea, Republic of)] [Department of Materials Science and Engineering, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju 500-757 (Korea, Republic of)

2012-10-15T23:59:59.000Z

446

Band Offsets at the Epitaxial Anatase TiO2/n-SrTiO3(001) Interface...  

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

to measure valence band offsets at the epitaxial anatase TiO2(002)n-SrTiO3(001) heterojunction prepared by molecular beam epitaxy, Within experimental error, the valance band...

447

Enhanced photocatalytic efficiency in zirconia buffered n-NiO/p-NiO single crystalline heterostructures by nanosecond laser treatment  

SciTech Connect

We report the formation of NiO based single crystalline p-n junctions with enhanced photocatalytic activity induced by pulsed laser irradiation. The NiO epilayers were grown on Si(001) substrates buffered with cubic yttria-stabilized zirconia (c-YSZ) by using pulsed laser deposition. The NiO/c-YSZ/Si heterostructures were subsequently laser treated by 5 pulses of KrF excimer laser (pulse duration = 25 Multiplication-Sign 10{sup -9} s) at lower energies. Microstructural studies, conducted by X-ray diffraction ({theta}-2{theta} and {phi} techniques) and high resolution transmission electron microscope, showed a cube-on-cube epitaxial relationship at the c-YSZ/Si interface; the epitaxial relationship across the NiO/c-YSZ interface was established as NiO<111 > Double-Vertical-Line Double-Vertical-Line c-YSZ<001> and in-plane NiO<110> Double-Vertical-Line Double-Vertical-Line c-YSZ<100>. Electron microscopy studies showed that the interface between the laser annealed and the pristine region as well as the NiO/c-YSZ interface was atomically sharp and crystallographically continuous. The formation of point defects, namely oxygen vacancies and NiO, due to the coupling of the laser photons with the NiO epilayers was confirmed by XPS. The p-type electrical characteristics of the pristine NiO epilayers turned to an n-type behavior and the electrical conductivity was increased by one order of magnitude after laser treatment. Photocatalytic activity of the pristine (p-NiO/c-YSZ/Si) and the laser-annealed (n-NiO/p-NiO/c-YSZ/Si) heterostructures were assessed by measuring the decomposition rate of 4-chlorophenol under UV light. The photocatalytic reaction rate constants were determined to be 0.0059 and 0.0092 min{sup -1} for the as-deposited and the laser-treated samples, respectively. The enhanced photocatalytic efficiency was attributed to the suppressed charge carrier recombination in the NiO based p-n junctions and higher electrical conductivity. Besides, the oxygen vacancies ease the adsorption of 4-chlorophenol, hydroxyl, and water molecules to the surface. Thus, n-NiO/p-NiO single crystalline catalysts can be introduced as a potent candidate to remediate the environmental pollution.

Molaei, R.; Bayati, M. R.; Alipour, H. M.; Nori, S.; Narayan, J. [Department of Materials Science and Engineering, NC State University, EB-1, Raleigh, North Carolina 27695-7907 (United States)] [Department of Materials Science and Engineering, NC State University, EB-1, Raleigh, North Carolina 27695-7907 (United States)

2013-06-21T23:59:59.000Z

448

Carrier-Controlled Ferromagnetism in SrTiO3  

Magnetotransport and superconducting properties are investigated for uniformly La-doped SrTiO3 films and GdTiO3/SrTiO3 heterostructures, respectively. GdTiO3/SrTiO3 interfaces exhibit a high-density 2D electron gas on the SrTiO3 side of the interface, while, for the SrTiO3 films, carriers are provided by the dopant atoms. Both types of samples exhibit ferromagnetism at low temperatures, as evidenced by a hysteresis in the magnetoresistance. For the uniformly doped SrTiO3 films, the Curie temperature is found to increase with doping and to coexist with superconductivity for carrier concentrations on the high-density side of the superconducting dome. The Curie temperature of the GdTiO3/SrTiO3 heterostructures scales with the thickness of the SrTiO3 quantum well. The results are used to construct a stability diagram for the ferromagnetic and superconducting phases of SrTiO3.

Moetakef, Pouya; Williams, James R.; Ouellette, Daniel G.; Kajdos, Adam P.; Goldhaber-Gordon, David; Allen, S. James; Stemmer, Susanne

2012-06-01T23:59:59.000Z

449

Ab initio Molecular Dynamics and Elastic Properties of TiC and TiN Nanoparticles A. V. Postnikov and P. Entel  

E-Print Network (OSTI)

Ab initio Molecular Dynamics and Elastic Properties of TiC and TiN Nanoparticles A. V. Postnikov composition and compared to frozen phonon and molecular dynamics calculations for crystalline TiC and Ti range of frequencies, including the phonon band gap of pure crystalline TiC (near 15 THz). Similar

Entel, P.

450

ALS in the News  

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

feed-image feed-image Digg: ALSBerkeleyLab Facebook Page: 208064938929 Flickr: advancedlightsource Twitter: ALSBerkeleyLab YouTube: AdvancedLightSource Home About the ALS ALS in the News ALS in the News Roman Seawater Concrete Holds the Secret to Cutting Carbon Emissions Print Tuesday, 04 June 2013 00:00 An international team led by Paulo Monteiro of the Advanced Light Source and UC Berkeley has analyzed samples of Roman concrete from harbor installations that have survived 2,000 years of chemical attack and wave action, "one of the most durable construction materials on the planet," says UC Berkeley's Marie Jackson, a leading member of the team. Says Monteiro, "It's not that modern concrete isn't good, but manufacturing Portland cement accounts for seven percent of the carbon dioxide that industry puts into the air." The carbon footprint of Roman concrete, made from lime, volcanic ash, and seawater, is much smaller.

451

ALS Beamlines Directory  

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

Beamlines Directory Beamlines Directory ALS Beamlines Directory Print Beamlines, Parameters, Contact Information, and Schedules Download a high-resolution version of the ALS Beamclock. See Beamclock to view the ALS energy-related beamlines beamclock. Beamline Parameters Beamline and endstation technical information is available through the links below. Unless otherwise noted, all beamlines are currently operational. Individual beamline schedules are posted when available. Please contact the responsible beamline scientist for additional schedule information. When calling from off-site, all beamline (BL) phone numbers that begin with a "2" are preceded by 495- (i.e., 495-2014); all others are preceded by 486-. Beamline Number Source Technique/ Group Name Energy Range Beamline Contact Schedule/BL Phone

452

Unusual activation of novel Au/TiO2/AI2O3 xH2O catalysts by calcination  

SciTech Connect

Au/Al{sub 2}O{sub 3} {center_dot} xH{sub 2}O and Au/TiO{sub 2}/Al{sub 2}O{sub 3} {center_dot} xH{sub 2}O (x = 0-3) catalysts were prepared by assembling gold nanoparticles on neat and TiO{sub 2}-modified Al{sub 2}O{sub 3}, AlOOH, and Al(OH){sub 3} supports, and their catalytic activity in CO oxidation was tested either as synthesized or after on-line pretreatment in O{sub 2}-He at 500 C. A promotional effect of TiO{sub 2} on the activity of gold catalysts was observed upon 500 C-pretreatment. The catalyst stability as a function of time on stream was tested in the absence or presence of H{sub 2}, and physiochemical characterization applying BET, ICP-OES, XRD, TEM, and {sup 27}Al MAS NMR was conducted.

Yan, Wenfu [ORNL; Ma, Zhen [ORNL; Mahurin, Shannon Mark [ORNL; Overbury, Steven {Steve} H [ORNL; Dai, Sheng [ORNL

2008-01-01T23:59:59.000Z

453

Paramagnetic neutron scattering from Ni (invited)  

Science Journals Connector (OSTI)

New polarized beammeasurements have been carried out in the paramagnetic phase of 6 0Ni in order to enlarge the (q ?) range previously studied by Steinsvoll e t a l. Magnetic scattering has been detected up to halfway to the zone boundary. The results can be successfully interpreted in terms of a diffusive?type scattering function over an unexpected wide (q ?) range qneutron data are also compared with the predictions of the very recent band model by Callaway. Finally we point out important similarities and differences in the paramagnetic scattering from localized systems such as EuO and itinerant systems and discuss the universality of the paramagnetic scattering function.

P. Böni; G. Shirane

1985-01-01T23:59:59.000Z

454

Reaction Mechanisms in the Li3AlH6/LiBH4 and Al/LiBH4 Systems for Reversible Hydrogen Storage. Part 1: H capacity and Role of Al  

SciTech Connect

Lithium-based complex hydrides, including lithium aluminum hydrides (LiAlH4, Li3AlH6) and lithium borohydride (LiBH4), are some of the most attractive materials for hydrogen storage due to their high hydrogen contents. In the present work, we investigated the hydrogen storage properties of combined systems of Li3AlH6-LiBH4 and Al-LiBH4, both of which exhibit favorable hydrogen storage properties owing to the formation of AlB2 during dehydrogenation. TGA data showed that TiCl3-doped Li3AlH6/2LiBH4 and 0.5Al/LiBH4 release ~ 8.8 and ~ 8.4 wt.% H2, respectively, with ~ 3.8 and ~ 5.8 wt.% release after rehydrogenation of the dehydrogenation product. XRD results identified LiH and AlB2 phases in the dehydrogenated products, which has suggested a mechanism by which Al contributes to the remarkable improvement of the reversible storage properties of LiBH4 in terms of the temperature and pressure for H2 release/uptake.

Choi, Young Joon; Lu, Jun; Sohn, Hong Yong; Fang, Zhigang Zak

2011-04-07T23:59:59.000Z

455

Effect of Pd on the Ni{sub 2}Si stress relaxation during the Ni-silicide formation at low temperature  

SciTech Connect

The thermally induced solid-state reaction between a 50-nm-thick Ni(6%Pd) layer and a Si(100) substrate was investigated using in situ and simultaneous x-ray diffraction and sheet resistance. The reaction begins with the growth of the stressed {delta}-Ni{sub 2}Si phase, and the transient {theta}-Ni{sub 2}Si. At the end of the {theta}-Ni{sub 2}Si consumption, a NiSi seed is formed. Then, the {delta}-Ni{sub 2}Si relaxation occurs simultaneously with its subsequent growth and the Pd out diffusion from the unreacted Ni(Pd) layer. It is suggested that the driving force for the Pd diffusion out of the metal layer is linked to both the higher solubility of Pd in NiSi compared to Ni{sub 2}Si and to the Ni{sub 2}Si relaxation.

Putero, M.; Mangelinck, D. [Aix-Marseille Univ., IM2NP, Faculte des Sciences de Jerome, F-13397 Marseille (France); CNRS, IM2NP-UMR 7334, Faculte des Sciences de Jerome, F-13397 Marseille (France)

2012-09-10T23:59:59.000Z

456

Effects of preformed alumina scales on the behavior of FeCrAl alloys in simulated coal-gasifier atmospheres  

Science Journals Connector (OSTI)

Iron-based mechanical alloys containing 3.2–6.6 Al, 16.0–24.7 Cr, 0.5 Ti, and 0.5 Y2O3 (mass%) were preoxidized in air at 1373 K for 10–180 min. Alumina scales were formed. Scales were isolated and examined in a ...

J. K. Richard Weber; M. G. Hocking

1989-08-01T23:59:59.000Z

457

Brambilla, et al. Reply  

E-Print Network (OSTI)

Brambilla, et al. Reply: van Megen and Williams (vMW) question our recent claim that dense colloidal hard spheres enter at large volume fraction \\phi a dynamical regime not observed in earlier work and not described by the mode-coupling theory (MCT) of the glass transition.

Giovanni Brambilla; Djamel El Masri; Matteo Pierno; Ludovic Berthier; Luca Cipelletti; George Petekidis; Andrew B. Schofield

2010-08-27T23:59:59.000Z

458

''Bare'' single-particle energies in Ni-56  

E-Print Network (OSTI)

The structure of the low-lying levels in the mirror nuclei Ni-57 and Cu-57 is described within the extended unified model. The problem of single-particle energies in Ni-56 is treated in detail. ''Bare'' single-particle energies are extracted from...

Trache, L.; Kolomiets, A.; Shlomo, S.; Heyde, K.; Dejbakhsh, H.; Gagliardi, Carl A.; Tribble, Robert E.; Zhou, XG; Jacob, VE; Oros, AM.

1996-01-01T23:59:59.000Z

459

Phase relations in the system Ni-As  

Science Journals Connector (OSTI)

...n' ' , / / I , 852(N_i,As)+VN',Asz+L+V ima+L+v/IpnncC;rVrlrl+V(NiAs)+NisAsz+V-, , I I// INIs.xAs +mama+ncll Ni,_xAS,+V/i +V +VJ[ Inc+prm+V , , , , , , , .i,, .! , . I0 20 30 40 50 60 70 Weight per...

R. A. Yund

460

Low temperature epitaxial growth of Ge on cube- textured Ni  

SciTech Connect

Quasi- single crystal Ge films were grown on [001]<010> textured Ni substrate at a temperature of 350 oC using an insulating buffer layer of CaF2. A direct deposition of Ge on Ni at 350 oC was shown to alloy with Ni. From x- ray pole figure analysis, it was shown that Ge grew epitaxially with the same orientation as CaF2 and the dispersions in the out- of- plane and in- plane directions were found to be 1.7 0.1o and 6 1o, respectively. In the out- of- plane direction, Ge[111]||CaF2[111]||Ni[001]. In addition, the Ge consisted of four equivalent in- plane oriented domains such that two mutually orthogonal directions: Ge 211 and Ge 011 are parallel to mutually orthogonal directions: Ni 110 and Ni 110 , respectively of the Ni(001) surface. This was shown to be originated from the four equivalent in- plane oriented domains of CaF2 created to minimize the mismatch strain between CaF2 and Ni in those directions.

GIARE, C [Rensselaer Polytechnic Institute (RPI); Palazzo, J [Rensselaer Polytechnic Institute (RPI); Goyal, Amit [ORNL; WANG, G [Rensselaer Polytechnic Institute (RPI); LU, T [Rensselaer Polytechnic Institute (RPI)

2012-01-01T23:59:59.000Z

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461

Autocatalytic decomposition of water on Ni(110)  

SciTech Connect

The interaction of water with clean Ni(110) at temperatures between 425 and 770 K has been studied by work function ([Delta][phi]), desorption mass analysis, and low-energy electron diffraction (LEED). Water is observed to dissociate on clean Ni(110), forming adsorbed oxygen and H[sub 2](g) in a process which is itself catalyzed (and hence termed autocatalytic) by the adsorbed oxygen product. Initial dissociation of water is believed to originate on defects where adsorbed oxygen then promotes growth of O (2 [times] 1) islands in a process which becomes self-poisoning in the limit of saturation of the (2 [times] 1) phase (0.5 ML (ML = monolayer)). The growth kinetics indicate the autocatalysis process is most active when the oxygen coverage is 0.1 ML. A statistical theory supported by computer simulation is developed which models the autocatalytic growth kinetics in terms of nucleation of islands along step edges. The temperature dependence of autocatalysis exhibits a maximum at approx. 600 K. This complex temperature dependence is explained in terms of transition-state theory. 25 refs., 10 figs.

Callen, B.W.; Griffiths, K.; Norton, P.R. (Univ. of Western Ontario, London (Canada)); Harrington, D.A. (Univ. of Victoria, British Columbia (Canada))

1992-12-24T23:59:59.000Z

463

Eine analytische Brennstoffzelle als Alkoholsensor  

Science Journals Connector (OSTI)

Es wird eine analytische Brennstoffzelle zur quantitativen Bestimmung von Alkoholen beschrieben. Als...

H. Huck