National Library of Energy BETA

Sample records for ni ti al

  1. The thermal stability of TiB[sub 2] in Ni-43 a% Al

    SciTech Connect (OSTI)

    Korinko, P.S. (General Motors, Indianapolis, IN (United States). Allison Gas Turbine Div.); Duquette, D.J. (Rensselaer Polytechnic Inst., Troy, NY (United States))

    1994-02-01

    The intermetallic compound NiAl has been suggested for use as a matrix for high temperature composites. Interest in this compound is derived from its low density compared to conventional superalloys, high melting point, and excellent oxidation resistance. It has been demonstrated that a composite of stoichiometric NiAl and TiB[sub 2] is stable when exposed at elevated temperatures for extended periods of time. However, it has been shown that a composite consisting of Ni[sub 3]Al and TiB[sub 2] is not stable in the same temperature range. In the case of Ni[sub 3]Al, the TiB[sub 2] particles dissolve and the matrix is enriched with Ti and transforms to Ni[sub 3](Al,Ti) and NiTi. If stoichiometric NiAl reinforced with TiB[sub 2] is used in a high temperature oxidizing atmosphere, then there is also a possibility that the Al may be depleted as it is oxidized. If this occurs, the composition of the matrix may shift to nickel-rich NiAl or even to Ni[sub 3]Al. This work was conducted to determine if TiB[sub 2] is used in a high temperature oxidizing atmosphere, then there is also a possibility that the Al may be depleted as it is oxidized. If this occurs, the composition of the matrix may shift to nickel-rich NiAl or even to Ni[sub 3]Al. This work was conducted to determine if TiB[sub 2] is stable in nickel-rich NiAl. The Ni-Al phase diagram is shown, and the composition of NiAl used in this study is indicated.

  2. Observation of Precipitation Evolution in Fe-Ni-Mn-Ti-Al Maraging Steel using Atom Probe Tomography

    SciTech Connect (OSTI)

    Pereloma, E. V.; Stohr, R A; Miller, Michael K; Ringer, S. P.

    2009-01-01

    We describe the full decomposition sequence in an Fe-Ni-Mn-Ti-Al maraging steel during isothermal annealing at 550 C. Following significant pre-precipitation clustering reactions within the supersaturated martensitic solid solution, (Ni,Fe){sub 3}Ti and (Ni,Fe){sub 3}(Al,Mn) precipitates eventually form after isothermal aging for {approx}60 seconds. The morphology of the (Ni,Fe){sub 3}Ti particles changes gradually during aging from predominantly plate-like to rod-like, and, importantly, Mn and Al were observed to segregate to these precipitate/matrix interfaces. The (Ni,Fe){sub 3}(Al,Mn) precipitates occurred at two main locations: uniformly within the matrix and at the periphery of the (Ni,Fe){sub 3}Ti particles. We relate this latter mode of precipitation to the Mn-Al segregation.

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

    SciTech Connect (OSTI)

    Okulov, I. V. Marr, T.; Schultz, L.; Eckert, J.; Kühn, U.; Freudenberger, J.; Oertel, C.-G.; Skrotzki, W.

    2014-02-17

    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.

  4. Brazing ZrO{sub 2} ceramic to Ti–6Al–4V alloy using NiCrSiB amorphous filler foil: Interfacial microstructure and joint properties

    SciTech Connect (OSTI)

    Cao, J., E-mail: cao_jian@hit.edu.cn [Shandong Provincial Key Laboratory of Special Welding Technology, Harbin Institute of Technology at Weihai, Weihai 264209 (China); State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Song, X.G., E-mail: song_xiaoguohit@yahoo.com.cn [Shandong Provincial Key Laboratory of Special Welding Technology, Harbin Institute of Technology at Weihai, Weihai 264209 (China); State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Li, C., E-mail: li_chun1989@yahoo.cn [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Zhao, L.Y., E-mail: Zhao_ly@163.com [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Feng, J.C., E-mail: feng_jicai@163.com [Shandong Provincial Key Laboratory of Special Welding Technology, Harbin Institute of Technology at Weihai, Weihai 264209 (China); State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China)

    2013-07-15

    Reliable brazing of ZrO{sub 2} ceramic and Ti–6Al–4V alloy was achieved using NiCrSiB amorphous filler foil. The interfacial microstructure of ZrO{sub 2}/Ti–6Al–4V joints was characterized by scanning electron microscope, energy dispersive spectrometer and micro-focused X-ray diffractometer. The effects of brazing temperature on the interfacial microstructure and joining properties of brazed joints were investigated in detail. Active Ti of Ti–6Al–4V alloy dissolved into molten filler metal and reacted with ZrO{sub 2} ceramic to form a continuous TiO reaction layer, which played an important role in brazing. Various reaction phases including Ti{sub 2}Ni, Ti{sub 5}Si{sub 3} and ?-Ti were formed in brazed joints. With an increasing of brazing temperature, the TiO layer thickened gradually while the Ti{sub 2}Ni amount reduced. Shear test indicated that brazed joints tend to fracture at the interface between ZrO{sub 2} ceramic and brazing seam or Ti{sub 2}Ni intermetallic layer. The maximum average shear strength reached 284.6 MPa when brazed at 1025 °C for 10 min. - Graphical Abstract: Interfacial microstructure of ZrO{sub 2}/TC4 joint brazed using NiCrSiB amorphous filler foil was: ZrO{sub 2}/TiO/Ti{sub 2}Ni + ?-Ti + Ti{sub 5}Si{sub 3}/?-Ti/Widmanstätten structure/TC4. - Highlights: • Brazing of ZrO{sub 2} ceramic and Ti-6Al-4V alloy was achieved. • Interfacial microstructure was TiO/Ti{sub 2}Ni + ? + Ti{sub 5}Si{sub 3}/?/Widmanstätten structure. • The formation of TiO produced the darkening effect of ZrO{sub 2} ceramic. • The highest joining strength of 284.6MPa was obtained.

  5. Effects of thermo-mechanical treatment on the shape memory behavior of NiTi and CoNiAl alloys 

    E-Print Network [OSTI]

    Karaca, Haluk Ersin

    2004-09-30

    Nickel-Titanium (NiTi) shape memory alloys have been the focus of extensive research due to its unique characteristics such as high recoverable strain and ductility. However, solutionized samples of NiTi do not demonstrate good shape memory...

  6. Microstructural Characterization and Shape Memory Response of Ni-Rich NiTiHf and NiTiZr High Temperature Shape Memory Alloys 

    E-Print Network [OSTI]

    Evirgen, Alper

    2014-08-14

    NiTiHf and NiTiZr high temperature shape memory alloys (HTSMAs) have drawn a great deal of attention as cheaper alternatives to Pt, Pd and Au alloyed NiTi-based HTSMAs while NiTiZr alloys also providing at least 20% weight reduction then its Ni...

  7. Engineering the Martensitic Transformation Hysteresis of Ni-Rich NiTi Alloys 

    E-Print Network [OSTI]

    Franco, Brian Eelan

    2014-12-18

    The shape memory behavior in NiTi alloys can be exploited for a wide variety of applications that require active materials. The application dictates the transformation temperatures and hysteresis of the alloy. NiTi alloys ...

  8. TiNi shape memory alloy thin films for microactuator application

    E-Print Network [OSTI]

    Fu, Yongqing

    TiNi films were prepared by co-sputtering TiNi target and a separate Ti target. Crystalline structure and phase transformation behaviors of TiNi films were investigated. Results showed that TiNi films had fine grain size ...

  9. Transformation Induced Fatigue of Ni-Rich NiTi Shape Memory Alloy Actuators 

    E-Print Network [OSTI]

    Schick, Justin Ryan

    2011-02-22

    In this work the transformation induced fatigue of Ni-rich NiTi shape memory alloys (SMAs) was investigated. The aerospace industry is currently considering implementing SMA actuators into new applications. However, before ...

  10. The combustion synthesis of Ni-Ti shape memory alloys

    SciTech Connect (OSTI)

    Moore, J.J.; Yi, H.C. (Colorado School of Mines, Golden (USA))

    1990-08-01

    Combustion synthesis of Ni-Ti-series shape-memory alloys yields both time and energy savings over conventional production methods. The solidified combustion synthesis process products have been cold-rolled into plates which exhibit the shape-memory effect, and it was noted that shape-memory transition temperatures may be tailored over a -78 to 460 C temperature range through the substitution of a third element for Ni; this element may be Pd or Fe. Accounts are given of the experimental combustion syntheses of Ni-Ti-Fe and Ti-Ni-Pd. 24 refs.

  11. TiNi-based thin films for MEMS applications

    E-Print Network [OSTI]

    Fu, Yongqing

    In this paper, some critical issues and problems in the development of TiNi thin films were discussed, including preparation and characterization considerations, residual stress and adhesion, frequency improvement, fatigue ...

  12. Electronic circuits having NiAl and Ni.sub.3 Al substrates

    DOE Patents [OSTI]

    Deevi, Seetharama C. (Midlothian, VA); Sikka, Vinod K. (Oak Ridge, TN)

    1999-01-01

    An electronic circuit component having improved mechanical properties and thermal conductivity comprises NiAl and/or Ni.sub.3 Al, upon which an alumina layer is formed prior to applying the conductive elements. Additional layers of copper-aluminum alloy or copper further improve mechanical strength and thermal conductivity.

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

    E-Print Network [OSTI]

    Kockar, Benat

    2009-05-15

    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 ...

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

    E-Print Network [OSTI]

    Meyers, Marc A.

    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

  15. Synthesis, electrochemistry and First Principles Calculation studies of layered Li-Ni-Ti-O compounds

    E-Print Network [OSTI]

    Kang, Kisuk

    New layered cathode materials, Li?.?Ni?.??Ti?.??O?, were synthesized by means of ion-exchange from Na?.?Ni?.??Ti?.??O?. The degree of cation disordering in the material depends critically on the synthesis conditions. Longer ...

  16. A Ni/surface-modified Diamond Composite Electroplating Coating on Superelastic NiTi Alloy as Potential Dental Bur Design

    E-Print Network [OSTI]

    Zheng, Yufeng

    A Ni/surface-modified Diamond Composite Electroplating Coating on Superelastic NiTi Alloy: Composite Electroplating; Surface-modified Diamond Particles; Interfacial Adhesion; NiTi alloy; Dental Bur into nickel coating, and its shank made of stainless steel. There are strong demands from the dentist

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

    E-Print Network [OSTI]

    2010-01-01

    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

  18. A=17Al (1993TI07)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01) (Not93TI07) (Not1959AJ76) (See the71AJ02)93TI07)Al

  19. The corrosion behavior and hemocompatibility of TiNi alloys coated with DLC by plasma based ion implantation

    E-Print Network [OSTI]

    Zheng, Yufeng

    The corrosion behavior and hemocompatibility of TiNi alloys coated with DLC by plasma based ion successfully deposited on Ti­50.8 at.% Ni alloys using plasma based ion implantation (PBII) technique on the surface modification of TiNi alloys, including ion implan- tation, multi arc ion-plating as well as Ti

  20. AlTiN layer effect on mechanical properties of Ti-doped diamond-like carbon composite coatings

    E-Print Network [OSTI]

    Volinsky, Alex A.

    AlTiN layer effect on mechanical properties of Ti-doped diamond-like carbon composite coatings Adhesion Ti/Ti-doped diamond-like carbon (DLC) and Ti/AlTiN/Ti-DLC composite coatings were deposited on the properties of these composite coatings was investigated through microstructure and mechanical properties

  1. Effect of Aging Heat Treatments on Ni52Ti48 Shape Memory Alloy 

    E-Print Network [OSTI]

    Akin, Erhan

    2011-10-21

    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...

  2. Lanthanide Al-Ni base Ericsson cycle magnetic refrigerants

    DOE Patents [OSTI]

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

    1995-10-31

    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.

  3. Irradiation study of Ti6Al4V and Ti6Al4V1B for FRIB beam dump: Experimental plan

    E-Print Network [OSTI]

    McDonald, Kirk

    Irradiation study of Ti6Al4V and Ti6Al4V1B for FRIB beam dump: Experimental plan Aida Amroussia;Motivation · Study of irradiation damage in Ti-6Al-4V and Ti-6Al-4V-1B · Irradiation with different particles boron addition improves mechanical properties of Ti-6Al-4V after irradiation? Are the changes

  4. Solution-based thermodynamic modeling of the Ni-Al-Mo system...

    Office of Scientific and Technical Information (OSTI)

    (Al,Mo,Ni)0.75(Al,Mo,Ni)0.25. Thus, -fcc and -Ni3Al are modeled with a single Gibbs free energy function with appropriate treatment of the chemical ordering contribution. In...

  5. Stable atomic structure of NiTi austenite

    SciTech Connect (OSTI)

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

    2014-08-01

    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.

  6. Biomaterials 24 (2003) 39313939 Corrosion and wear-corrosion behavior of NiTi modified

    E-Print Network [OSTI]

    Crone, Wendy C.

    2003-01-01

    Biomaterials 24 (2003) 3931­3939 Corrosion and wear-corrosion behavior of NiTi modified by plasma, aerospace, and automotive industries. NiTi alloys are important materials for biomedical and dental devices. The alloy has been used for making orthodontic dental arch wires and medical guide wires for diagnostic

  7. Superelastic and cyclic response of NiTi SMA at various strain rates and temperatures

    E-Print Network [OSTI]

    Nemat-Nasser, Sia

    in the range of 77­400 K. The influence of the annealing temperature on the fatigue response is also examined of NiTi SMAs depend on the annealing temperature; (2) in cyclic loading, the dissipated energy over loading rates, NiTi SMAs show properties similar to ordinary steels, as has been established by the first

  8. Features of a priori heavy doping of the n-TiNiSn intermetallic semiconductor

    SciTech Connect (OSTI)

    Romaka, V. A.; Rogl, P.; Romaka, V. V.; Hlil, E. K.; Stadnyk, Yu. V.; Budgerak, S. M.

    2011-07-15

    The crystal structure, the distribution of electron density, and the energy, kinetic, and magnetic properties of the n-TiNiSn intermetallic semiconductor are investigated. It is shown that a priori doping of n-TiNiSn with donors originates from partial, up to 0.5 at %, redistribution of Ti and Ni atoms in crystallographic sites of Ti atoms. The correlation is established between the donor concentration, amplitude of modulation of the continuous energy bands, and degree of filling of low-scale fluctuation potential wells with charge carriers. The results obtained are discussed within the Shklovskii-Efros model of a heavily doped and compensated semiconductor.

  9. A numerical method for predicting the bending fatigue life of NiTi and stainless steel root canal

    E-Print Network [OSTI]

    Zheng, Yufeng

    A numerical method for predicting the bending fatigue life of NiTi and stainless steel root canal. A numerical method for predicting the bending fatigue life of NiTi and stainless steel root canal instruments­titanium alloy (NiTi) and stainless steel (SS) endodontic files using finite element analysis. Methodology

  10. Electronic and structural influence of Ni by Pd substitution on the hydrogenation properties of TiNi

    SciTech Connect (OSTI)

    Emami, Hoda; Souques, Raphaeel; Crivello, Jean-Claude; Cuevas, Fermin

    2013-02-15

    In Ti (Ni,Pd) compounds, the hydrogen capacity and the stability of their hydrides decreases when Ni is partially substituted by larger in size Pd atoms. To understand this peculiar behaviour, the crystal structure of TiNi{sub 1-x}Pd{sub x}D{sub y} (x=0.1, 0.3 and 0.5) deuterides and the stability of TiNi{sub 1-x}Pd{sub x} (0{<=}x{<=}0.5) intermetallics and their hydrides have been investigated by both neutron diffraction experiments and Density Functional Theory (DFT) calculations. Neutron diffraction shows that at x=0.1 and 0.3, deuterium absorption induces tetragonal distortion in intermetallics sublattice whereas at x=0.5 the cubic symmetry is preserved. The structural properties and the heat of formation of TiNi{sub 1-x}Pd{sub x} (0{<=}x{<=}0.5) intermetallics and their hydrides have been determined by DFT. These results show that Pd substitution increases the stability of the intermetallics and decreases the stability of the hydrides, which confirms the rule of reverse stability. - Graphical abstract: Crystal structure of Ti(Ni,Pd)Hy hydrides in the I4/mmm space group. Highlights: Black-Right-Pointing-Pointer Neutron Diffraction and DFT calculations have been done on TiNi{sub 1-x}Pd{sub x}H{sub y} compounds. Black-Right-Pointing-Pointer Electronic effect of Pd substitution governs the hydrogenation properties in TiNi. Black-Right-Pointing-Pointer The rule of reverse stability in intermetallics/hydrides is observed with Pd substitution. Black-Right-Pointing-Pointer The hydrogen atoms in the I4/mmm structure prefer to occupy the 16n site.

  11. Nanoscale compositional analysis of NiTi shape memory alloy films deposited by DC magnetron sputtering

    SciTech Connect (OSTI)

    Sharma, S. K.; Mohan, S.; Bysakh, S.; Kumar, A.; Kamat, S. V.

    2013-11-15

    The formation of surface oxide layer as well as compositional changes along the thickness for NiTi shape memory alloy thin films deposited by direct current magnetron sputtering at substrate temperature of 300 °C in the as-deposited condition as well as in the postannealed (at 600 °C) condition have been thoroughly studied by using secondary ion mass spectroscopy, x-ray photoelectron spectroscopy, and scanning transmission electron microscopy-energy dispersive x-ray spectroscopy techniques. Formation of titanium oxide (predominantly titanium dioxide) layer was observed in both as-deposited and postannealed NiTi films, although the oxide layer was much thinner (8 nm) in as-deposited condition. The depletion of Ti and enrichment of Ni below the oxide layer in postannealed films also resulted in the formation of a graded microstructure consisting of titanium oxide, Ni{sub 3}Ti, and B2 NiTi. A uniform composition of B2 NiTi was obtained in the postannealed film only below a depth of 200–250 nm from the surface. Postannealed film also exhibited formation of a ternary silicide (Ni{sub x}Ti{sub y}Si) at the film–substrate interface, whereas no silicide was seen in the as-deposited film. The formation of silicide also caused a depletion of Ni in the film in a region ?250–300 nm just above the film substrate interface.

  12. Application of cluster-plus-glue-atom model to barrierless Cu–Ni–Ti and Cu–Ni–Ta films

    SciTech Connect (OSTI)

    Li, Xiaona, E-mail: lixiaona@dlut.edu.cn; Ding, Jianxin; Wang, Miao; Dong, Chuang [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024 (China); Chu, Jinn P. [Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China)

    2014-11-01

    To improve the thermal stability of copper and avoid its diffusion into surrounding dielectrics or interfacial reactions with them, the authors applied the cluster-plus-glue-atom model to investigate barrierless Cu–Ni–M (M?=?Ti or Ta) seed layers. The dissolution of the third element (Ti or Ta) in the Cu lattice with the aid of Ni significantly improved the thermal stability of the Cu seed layer. The appropriate M/Ni (M?=?Ti or Ta) ratio was selected to obtain a low resistivity: the resistivity was as low as 2.5??? cm for the (Ti{sub 1.5/13.5}Ni{sub 12/13.5}){sub 0.3}Cu{sub 99.7} film and 2.8??? cm for the (Ta{sub 1.1/13.1}Ni{sub 12/13.1}){sub 0.4}Cu{sub 99.6} film after annealing at 500?°C for 1?h. After annealing at 500?°C for 40?h, the two films remained stable without forming a Cu{sub 3}Si compound. The authors confirmed that the range of applications of the cluster-plus-glue-atom model could be extended. Therefore, a third element M with negative enthalpies of mixing with both Cu and Ni could be selected, under the premise that the mixing enthalpy of M–Ni is more negative than that of M–Cu.

  13. Thermomechanical behavior of 55Ni45Ti nitinol

    SciTech Connect (OSTI)

    Ford, D.S.; White, S.R. [Univ. of Illinois, Urbana, IL (United States)] [Univ. of Illinois, Urbana, IL (United States)

    1996-06-01

    Extensive and full range mechanical testing of 55Ni45Ti nitinol alloy wire up to failure over a wide range of testing temperatures is reported. Thermomechanical properties are obtained including: initial modulus, secondary modulus, critical martensitic start and finish stresses, plastic flow stress, recovery strain limit, failure stress and plastic modulus. The data is correlated with the Brinson constitutive model modified to account for full range loading. The ratio of austenite to martensite moduli was found to be 5.8 and the secondary modulus (stress-induced martensite) was found to be smaller by a factor of two when compared to the modulus of (stress-free) thermally induced martensite. The influence of the initial temperature treatment of the nitinol was shown to be pronounced within the transformation range. Reasonably accurate correlation is obtained with the modified Brinson constitutive model although there is some discrepancy in critical stress predictions which is partially attributed to experimental scatter.

  14. The first principle study of Ni{sub 2}ScGa and Ni{sub 2}TiGa

    SciTech Connect (OSTI)

    Özduran, Mustafa; Turgut, Kemal; Arikan, Nihat; ?yigör, Ahmet; Candan, Abdullah

    2014-10-06

    We computed the electronic structure, elastic moduli, vibrational properties, and Ni{sub 2}TiGa and Ni{sub 2}ScGa alloys in the cubic L2{sub 1} structure. The obtained equilibrium lattice constants of these alloys are in good agreement with available data. In cubic systems, there are three independent elastic constants, namely C{sub 11}, C{sub 12} and C{sub 44}. We calculated elastic constants in L2{sub 1} structure for Ni{sub 2}TiGa and Ni{sub 2}ScGa using the energy-strain method. The electronic band structure, total and partial density of states for these alloys were investigated within density functional theory using the plane-wave pseudopotential method implemented in Quantum-Espresso program package. From band structure, total and projected density of states, we observed metallic characters of these compounds. The electronic calculation indicate that the predominant contributions of the density of states at Fermi level come from the Ni 3d states and Sc 3d states for Ni{sub 2}TiGa, Ni 3d states and Sc 3d states for Ni{sub 2}ScGa. The computed density of states at Fermi energy are 2.22 states/eV Cell for Ni{sub 2}TiGa, 0.76 states/eV Cell for Ni{sub 2}ScGa. The vibrational properties were obtained using a linear response in the framework at the density functional perturbation theory. For the alloys, the results show that the L2{sub 1} phase is unstable since the phonon calculations have imagine modes.

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

    E-Print Network [OSTI]

    Vandygriff, Eric Layton

    2002-01-01

    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...

  16. Shape-Memory Transformations of NiTi: Minimum-Energy Pathways...

    Office of Scientific and Technical Information (OSTI)

    Details In-Document Search This content will become publicly available on December 24, 2015 Title: Shape-Memory Transformations of NiTi: Minimum-Energy Pathways between Austenite,...

  17. Low Spring Index NiTi Coil Actuators for Use in Active Compression Garments

    E-Print Network [OSTI]

    Holschuh, Bradley T.

    This paper describes the modeling, development, and testing of low spring index nickel titanium (NiTi) coil actuators designed for use in wearable compression garments, and presents a prototype tourniquet system using these ...

  18. The thermomechanical constitutive experimentation of NiTi shape memory alloy strips and rods 

    E-Print Network [OSTI]

    Howard, Stephen David

    1995-01-01

    The purpose of this thesis was to study the effect of temperature on the thermomechanical constitutive behavior of NiTi shape memory alloy strip and rod specimens. The stress-strain relationship is analyzed for isothermal monotonic tensile testing...

  19. Eutectic bonding of a Ti sputter coated, carbon aerogel wafer to a Ni foil

    SciTech Connect (OSTI)

    Jankowski, A.F.; Hayes, J.P.; Kanna, R.L.

    1994-06-01

    The formation of high energy density, storage devices is achievable using composite material systems. Alternate layering of carbon aerogel wafers and Ni foils with rnicroporous separators is a prospective composite for capacitor applications. An inherent problem exists to form a physical bond between Ni and the porous carbon wafer. The bonding process must be limited to temperatures less than 1000{degrees}C, at which point the aerogel begins to degrade. The advantage of a low temperature eutectic in the Ni-Ti alloy system solves this problem. Ti, a carbide former, is readily adherent as a sputter deposited thin film onto the carbon wafer. A vacuum bonding process is then used to join the Ni foil and Ti coating through eutectic phase formation. The parameters required for successfld bonding are described along with a structural characterization of the Ni foil-carbon aerogel wafer interface.

  20. Fabrication of NiTi shape memory alloy from elemental powders by hot isostatic pressing 

    E-Print Network [OSTI]

    McNeese, Matthew Doyle

    1997-01-01

    .0 and 50.6at.% Ni, packed and sealed into stainless steel containers, hot isostatically pressed (HIPed) at 20OMPa and 900-1050 'C, and machined to expose a gauge section of consolidated NiTi material for thennomechanical testing. Some samples of material...

  1. Finite Element Based Micromechanical Analysis of Precipitated NiTi Shape Memory Alloys 

    E-Print Network [OSTI]

    Cox, Austin Edward

    2015-07-22

    into the material and its thermomechanical response than ever before. The most widely modeled and produced SMA class in industry today is one which hosts Ni as a core component of its composition, and usually takes the form of NiTi. When these SMA materials are heat...

  2. TI--CR--AL--O thin film resistors

    DOE Patents [OSTI]

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

    2000-01-01

    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.

  3. Metallic glass alloys of Zr, Ti, Cu and Ni

    DOE Patents [OSTI]

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

    1997-01-01

    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.

  4. High strain rate deformation of NiAl

    SciTech Connect (OSTI)

    Maloy, S.A.; Gray, G.T. III; Darolia, R.

    1994-07-01

    NiAl is a potential high temperature structural material. Applications for which NiAl is being considered (such as rotating components in jet engines) requires knowledge of mechanical properties over a wide range of strain rates. Single crystal NiAl (stoichiometric and Ni 49.75Al 0.25Fe) has been deformed in compression along [100] at strain rates of 0.001, 0.1/s and 2000/s and temperatures of 76,298 and 773K. <111> slip was observed after 76K testing at a strain rate of 0.001/s and 298K testing at a strain rate of 2000/s. Kinking was observed after deformation at 298K and a strain rate of 0.001/s and sometimes at 298 K and a strain rate of 0.1/s. Strain hardening rates of 8200 and 4000 MPa were observed after 773 and 298K testing respectively, at a strain rate of 2000/s. Results are discussed in reference to resulting dislocation substructure.

  5. Production of Ni-Cr-Ti-natural fibres composite and investigation of mechanical properties

    SciTech Connect (OSTI)

    Pesmen, G.; Erol, A.

    2015-03-30

    Intermetallic materials such as Ni{sub 2}Ti, Cr{sub 2}Ti are among advanced technology materials that have outstanding mechanical and physical properties for high temperature applications. Especially creep resistance, low density and high hardness properties stand out in such intermetallics. The microstructure, mechanical properties of (%50Ni-%48Cr-%2Ti)-%10Naturel Fibres and (%64Ni-%32Cr-%4Ti)-%10Naturel Fibres powders were investigated using specimens produced by tube furnace sintering at 1000-1200-1400°C temperature. A composite consisting of ternary additions, a metallic phase, Ti,Cr and Ni have been prepared under Ar shroud and then tube furnace sintered. XRD, SEM (Scanning Electron Microscope), were investigated to characterize the properties of the specimens. Experimental results carried out for composition (%64Ni-%32Cr-%4Ti)-%10Naturel at 1400°C suggest that the best properties as 112.09HV and 5,422g/cm{sup 3} density were obtained at 1400°C.

  6. Three-dimensional multimodal imaging and analysis of biphasic microstructure in a Ti-Ni-Sn thermoelectric material

    E-Print Network [OSTI]

    Douglas, Jason E; Echlin, McLean P; Lenthe, William C; Seshadri, Ram; Pollock, Tresa M

    2015-01-01

    microstructure in a Ti–Ni–Sn thermoelectric material Jasonsolid-state option. Thermoelectric materials, which convertin biphasic hH- based thermoelectric materials. This work

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

    E-Print Network [OSTI]

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

    2006-06-12

    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

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

    SciTech Connect (OSTI)

    Saadi, Souheil

    2011-03-01

    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.

  9. Metallic glass alloys of Zr, Ti, Cu and Ni

    DOE Patents [OSTI]

    Lin, X.; Peker, A.; Johnson, W.L.

    1997-04-08

    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{minus}x}Ti{sub x}){sub a} Cu{sub b} (Ni{sub 1{minus}y}Co{sub y}){sub c} wherein x is from 0.1 to 0.3, y{center_dot}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. 2 figs.

  10. Strain-Dependence of the Structure and Ferroic Properties of Epitaxial NiTiO3Thin Films Grown on Different Substrates

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

    Varga, Tamas; Droubay, Timothy C.; Bowden, Mark E.; Kovarik, Libor; Hu, Dehong; Chambers, Scott A.

    2015-01-01

    Polarization-induced weak ferromagnetism has been predicted a few years back in perovskite MTiO3(M = Fe, Mn, and Ni). We set out to stabilize this metastable perovskite structure by growing NiTiO3epitaxially on different substrates and to investigate the dependence of polar and magnetic properties on strain. Epitaxial NiTiO3films were deposited on Al2O3, Fe2O3, and LiNbO3substrates by pulsed laser deposition and characterized using several techniques. The effect of substrate choice on lattice strain, film structure, and physical properties was investigated. Our structural data from X-ray diffraction and electron microscopy shows that substrate-induced strain has a marked effect on the structure and crystallinemore »quality of the films. Physical property measurements reveal a dependence of the weak ferromagnetism and lattice polarization on strain and highlight our ability to control the ferroic properties in NiTiO3thin films by the choice of substrate. Our results are also consistent with the theoretical prediction that the ferromagnetism in acentric NiTiO3is polarization induced. From the substrates studied here, the perovskite substrate LiNbO3proved to be the most promising one for strong multiferroism.« less

  11. Surface roughness and interface width scaling of magnetron sputter deposited Ni/Ti multilayers

    SciTech Connect (OSTI)

    Maidul Haque, S.; Biswas, A.; Tokas, R. B.; Bhattacharyya, D.; Sahoo, N. K.; Bhattacharya, Debarati

    2013-09-14

    Using an indigenously built r.f. magnetron sputtering system, several single layer Ti and Ni films have been deposited at varying deposition conditions. All the samples have been characterized by Grazing Incidence X-ray Reflectivity (GIXR) and Atomic Force Microscopy to estimate their thickness, density, and roughness and a power law dependence of the surface roughness on the film thickness has been established. Subsequently, at optimized deposition condition of Ti and Ni, four Ni/Ti multilayers of 11-layer, 21-layer, 31-layer, and 51-layer having different bilayer thickness have been deposited. The multilayer samples have been characterized by GIXR and neutron reflectivity measurements and the experimental data have been fitted assuming an appropriate sample structure. A power law correlation between the interface width and bilayer thickness has been observed for the multilayer samples, which was explained in the light of alternate roughening/smoothening of multilayers and assuming that at the interface the growth “restarts” every time.

  12. Compton Profile Study of Intermetallic Ti{sub 3}Al

    SciTech Connect (OSTI)

    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)

    2011-10-20

    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.

  13. A=16Al (1993TI07)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01) (Not illustrated)59AJ76) (See the Energy6 -93TI07)

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

    E-Print Network [OSTI]

    Ciobanu, Cristian

    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

  15. Effect of aspect ratios of in situ formed TiB whiskers on the mechanical properties of TiBw/Ti6Al4V composites

    E-Print Network [OSTI]

    Hong, Soon Hyung

    online 27 December 2011 Ti alloy matrix composites reinforced with nanosized TiB whiskers (TiBw/Ti­6Al­4V composites (TMCs) reinforced using disparate ceramics as reinforcing agents have been of great interest­4V composites Min Young Koo,a Jae Sung Park,a Min Kyu Park,b Kyung Tae Kimc and Soon Hyung Honga

  16. 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 by warming above 210 K. Adsorption and reaction of 1,3-butadiene on NiAl(001), and thin films of -Al2O3, have (LID-FTMS), AES, and LEED. We find that at 170 K, the 1,3-butadiene is irreversibly -bonded to NiAl(001

  17. Energies of Electronic States of Ni (II) Ion in NiO-Al2O3 Catalyst Prepared by Impregnation

    SciTech Connect (OSTI)

    Obadovic, D. Z.; Kiurski, J.; Marinkovic-Neducin, R. P.

    2007-04-23

    The behavior of NiO-Al2O3 catalysts is strongly dependent on the preparation method, as well as on pretreatment conditions. In the present work we investigated the influences of Ni(II) ion on NiO-Al2O3 catalysts properties due to the preparation by impregnation method. Based on experimental diffuse reflectance spectroscopy (DRS) data of electronic d-d transitions of Ni (II) promoter ion the energies of electronic states in spinel-like structure were calculated, and the most probable scheme of molecular orbital have been proposed.

  18. Surface characteristics and corrosion resistance properties of TiNi shape memory alloy coated with Ta

    E-Print Network [OSTI]

    Zheng, Yufeng

    for electroplated, crimped, or swaged metal bands that can be abrasive, loosen, crack, or fall off. For coatingSurface characteristics and corrosion resistance properties of TiNi shape memory alloy coated coated with tantalum by the arc ion plating method with the aim to improve their radiopacity. Surface

  19. Grain size dependence of fracture toughness and crack-growth resistance of superelastic NiTi

    E-Print Network [OSTI]

    Sun, Qing-Ping

    Available online xxxx Keywords: Shape memory alloys Martensitic phase transformation Microstructure to a reversible martensitic phase transformation (PT), superelastic (SE) NiTi shape memory alloys (SMAs with thickness of 1.7 mm were sandwiched in stainless steel sheets and were cold-rolled to 42% of thickness

  20. Tantalum coated NiTi alloy by PIIID for biomedical application Y. Zhou a,b

    E-Print Network [OSTI]

    Zheng, Yufeng

    by electrodeposition [14], magnetron sputtering [15], plasma immersion ion implantation (PIII) [16,17] and multi-arc November 2012 Keywords: PIIID Ta coating Corrosion resistance NiTi Plasma immersion ion implantation technique combines the advantages of plasma immer- sion ion implantation (PIII) and magnetron deposition

  1. Investigation of surface endothelialization on biomedical nitinol (NiTi) alloy: Effects of surface micropatterning combined

    E-Print Network [OSTI]

    Lee, James

    Investigation of surface endothelialization on biomedical nitinol (NiTi) alloy: Effects of surface outstanding biocompatibility in our previous studies. In this study, endothelialization on biomedical nitinol- trolled thickness between 40 and 50 nm were deposited onto micropatterned nitinol surface in a direct

  2. Deformation behavior and dislocation mechanisms in TiAl alloys

    SciTech Connect (OSTI)

    Sriram, S.; Vasudevan, V.K. [Univ. of Cincinnati, OH (United States). Dept. of Materials Science and Engineering; Dimiduk, D.M. [Wright Lab., Wright-Patterson AFB, OH (United States)

    1995-08-01

    Polycrystalline Ti-50 and Ti-52Al (in at.%) alloys, with large grain sizes (50Al-300{mu}m, 52Al-500{mu}m) and containing low ({approximately}250 wt.ppm) levels of oxygen were deformed under compression over a wide temperature range (77--1,173 K). The 0.2% proof stress-temperature profiles comprise of three distinct regimes: Regime 1 (between 77--{approximately}600 K), regime 2 (between {approximately}600--1,073 K), and regime 3 (above 1,073 K). Deformation temperature influences the types of dislocations present, the nature of superdislocation dissociations, and the morphological characteristics of both ordinary and super dislocations. Collectively, experiment and theory suggest that the flow properties at low temperatures (regime 1) are controlled by lattice friction, whereas at higher temperatures (regime 2) the properties are dislocation obstacle controlled.

  3. A Si Photocathode Protected and Activated with a Catalytic Ti and Ni Composite Film for Solar Hydrogen Production in Water

    E-Print Network [OSTI]

    Lai, Yi-Hsuan; Park, Hyun S.; Zhang, Jenny Z.; Matthews, Peter D.; Wright, Dominic S.; Reisner, Erwin

    2015-02-04

    is consistent with the Ni species having a higher formal oxidation state than TiNicat and similar electronic characteristics to Ni(OH)2 and NiO. The Fourier-transformed Ni extended X-ray absorption fine structure (FT EXAFS) c(k)k2 spectrum of hydro- lyzed Ti... -based O2 evolution electrocata- lysts and photoanodes are only functional in neutral or alkaline conditions. However, operating close to pH neutral conditions can give rise to a pH gradient at the electrode surface.[13] This may lead to a non-optimal fill...

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

    DOE Patents [OSTI]

    Tiegs, T.N.; McDonald, R.R.

    1990-04-24

    An improved ceramic-metal composite is described comprising a mixture of a ceramic material with a ductile intermetallic alloy, preferably Ni[sub 3]Al. 2 figs.

  5. Ductile Ni.sub.3 Al alloys as bonding agents for ceramic materials in cutting tools

    DOE Patents [OSTI]

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

    1991-01-01

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

  6. Ductile Ni[sub 3]Al alloys as bonding agents for ceramic materials in cutting tools

    DOE Patents [OSTI]

    Tiegs, T.N.; McDonald, R.R.

    1991-05-14

    An improved ceramic-metal composite comprising a mixture of a ceramic material with a ductile intermetallic alloy, preferably Ni[sub 3]Al is disclosed. 2 figures.

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

    E-Print Network [OSTI]

    Sparks, Donald L.

    Mechanism(s) of Ni Sorption on Al-Hydroxy-Interlayered Vermiculite Using Time-Resolved EXAFS D. R sorbed and the mechanism of Ni sorption. #12;

  8. Effect of pulse frequency on microstructural, nanomechanical, and wear properties of electrodeposited Ni–TiN composite coatings

    SciTech Connect (OSTI)

    Xia, Fafeng; Tian, Jiyu; Ma, Chunyang Guo, Xue; Potts, Matt

    2014-12-21

    The current paper reports successful syntheses of Ni–TiN composite coatings by pulse electrodeposition. The effect of pulse frequency on the microstructures, nanomechanical, and wear properties of the coatings was investigated using transmission electron microscopy, X–ray diffraction, nanoindenter, scanning electron microscopy, and wear test instrument. The results showed that the Ni–TiN composite coating prepared at the pulse frequency of 100?Hz showed the presence of a less number of TiN particles and some degrees of aggregation in micro-regions. By contrast, in the Ni–TiN coating deposited at the pulse frequency of 500?Hz, the TiN particles were large in number and dispersed homogeneously, thereby, offering the coating a uniform and fine structure. The average grain diameters of Ni and TiN in the coating prepared at 100?Hz were 154.7 and 44.8?nm, respectively, whereas those for the coating prepared at 500?Hz were 67.3 and 25.9?nm, respectively. The maximum TiN content in the Ni-TiN coating deposited at 800?Hz was approximately 10.5?wt.?%. The maximum microhardness and the Young's modulus values for the Ni–TiN composite coatings deposited at 800?Hz were 35.7?GPa and 167.4?GPa, respectively. Furthermore, the Ni–TiN composite coating prepared at 100?Hz had more severe damages, whereas the morphologies of worn surface of the coatings deposited at 500?Hz and 800?Hz were smooth and only a few small pits appeared on the surface.

  9. Adhesion evaluation of TiN and (Ti, Al)N coatings on titanium 6Al-4V

    SciTech Connect (OSTI)

    James, R.D.; Gruss, K.A.; Horie, Y.; Davis, R.F.; Paisley, D.L.; Parthasarthi, S.; Tittmann, B.R.

    1996-12-31

    The metallic components of gas turbine engines are continually subjected to hostile atmospheres. Nitride coatings improve the performance of the metallic compressor blades in these engines. To assess the adhesion of nitride coatings on metals, titanium 6% aluminum 4% vanadium substrates were coated with titanium nitride (TiN) using both cathodic arc and electron beam evaporation. Titanium aluminum nitride ((Ti, Al)N) was also deposited using cathodic arc evaporation. The interfaces of the coated samples were loaded in tension using a high speed shock wave which caused spallation either at the interface, in the coating or in the metal. Scanning acoustic microscopy analysis of the spalled samples detected delaminations at the interface in the samples deposited by cathodic arc evaporation. DYNA2D modeling of plate impact spallation experiments revealed the tensile adhesion strength for TiN deposited by both techniques was {approx} 2.0 GPa. The tensile adhesion strength for (Ti, Al)N was less than 1.5 GPa.

  10. Shape memory response and microstructural evolution of a severe plastically deformed high temperature shape memory alloy (NiTiHf) 

    E-Print Network [OSTI]

    Simon, Anish Abraham

    2006-04-12

    NiTiHf alloys have attracted considerable attention as potential high temperature Shape Memory Alloy (SMA) but the instability in transformation temperatures and significant irrecoverable strain during thermal cycling under constant stress remains a...

  11. Properties of Ni-Al under shock loading

    SciTech Connect (OSTI)

    Koskelo, A. C.; McClellan, K. J.; Brooks, J. D.; Paisley, Dennis L.; Swift, D. C.

    2002-01-01

    New models for the dynamic response of materials will be based increasingly on better understanding and representation of processes occurring at the microstructural level. These developments require advances in diagnostics and models which can be applied explicitly to microstructural response. Various phenomena occur at the microstructural level which are generally ignored or averaged out in continuum-level models. One example of such 'irregular hydrodynamics' is the roughness imparted to a shock wave as it propagates through a polycrystalline material. We have developed imaging techniques to study spatial variations in shock propagation through polycrystalline materials. In order to interpret spatially-resolved data from polycrystal samples, we need to compare with simulations which represent the microstructure. Here we describe work undertaken to develop a model of the dynamic response of individual grains. The material chosen was Ni-Al alloy, because it exhibits a relatively large degree of elastic anisotropy, and it is relatively easy to manufacture.

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

    SciTech Connect (OSTI)

    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)

    2014-08-15

    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.

  13. High Temperature coatings based on {beta}-NiAI

    SciTech Connect (OSTI)

    Severs, Kevin

    2012-07-10

    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.

  14. Structure and magnetic properties of Ce?(Ni/Al/Ga)??-A...

    Office of Scientific and Technical Information (OSTI)

    Ce(NiAlGa)-A new phase with the LaAl structure type Janka, Oliver Univ. of California, Davis, CA (United States); Westfalische Wilhelms-Universitat, Munster...

  15. Irradiation study of Ti6Al4V and Ti6Al4V1B for FRIB beam dump: Aida Amroussia, PhD Student

    E-Print Network [OSTI]

    McDonald, Kirk

    Irradiation study of Ti6Al4V and Ti6Al4V1B for FRIB beam dump: Aida Amroussia, PhD Student Chemical Engineering and Materials Science Michigan State University May 19, 2014 1 #12;Outline · Irradiation-EBSD · Nano-indentation tests · Vickers Hardness tests · Insitu-tensile tests 2 #12;Irradiation experiments

  16. Irradiation study of Ti6Al4V and Ti6Al4V1B for FRIB beam dump: Preliminary results

    E-Print Network [OSTI]

    McDonald, Kirk

    Irradiation study of Ti6Al4V and Ti6Al4V1B for FRIB beam dump: Preliminary results Aida Amroussia;Outline · Irradiation of samples with high energy heavy ions (NSCL- MSU)(Ca 40 @ 50 MeV/u) and low energy the same areas on the samples before and after irradiation. 2 #12;Observations · Deterioration

  17. Synthesis of mesoporous NiO doped TiO{sub 2} submicrosphere via spray hydrolysis

    SciTech Connect (OSTI)

    Bahadur, J.; Sen, D.; Prakash, J.; Singh, Ripandeep; Paul, B.; Mazumder, S.; Sathiyamoorthy, D.

    2012-06-05

    NiO doped TiO{sub 2} submicrosphere have been prepared via spray hydrolysis. The doping concentration has been varied form 2 wt% to 15 wt%. Morphology of the submicrospheres has been investigated using small-angle neutron scattering and scanning electron microscopy. Elemental analysis has been carried out by energy dispersive X-ray analysis which confirms the doping concentrations. The mesopores in submicrospheres possess cylindrical morphology.

  18. The effect of substrate constraint on the martensitic transformation of Ni-Ti thin films

    SciTech Connect (OSTI)

    Mathews, S.A.; Wuttig, M.; Su, Q. [Univ. of Maryland, College Park, MD (United States). Dept. of Materials and Nuclear Engineering

    1996-09-01

    Previous work on an equiatomic alloy of nickel and titanium (nitinol) indicates that the martensitic transformation in thin films may be suppressed by interfacial constraint imposed by the substrate. Ni{sub 50}Ti{sub 50} films were deposited at room temperature on oxidized (100) Si substrates and tested to determine when the martensitic transformation occurred for both attached and free-standing conditions.

  19. Method For Making Electronic Circuits Having Nial And Ni3al Substrates

    DOE Patents [OSTI]

    Deevi, Seetharama C. (Midlothian, VA); Sikka, Vinod K. (Oak Ridge, TN)

    2001-01-30

    A method for making electronic circuit component having improved mechanical properties and thermal conductivity comprises steps of providing NiAl and/or Ni.sub.3 Al, and forming an alumina layer thereupon prior to applying the conductive elements. Additional layers of copper-aluminum alloy or copper further improve mechanical strength and thermal conductivity.

  20. Hydrogen dissociation and diffusion on Ni-and Ti-doped Mg,,0001... M. Pozzo,1,2

    E-Print Network [OSTI]

    Alfè, Dario

    Hydrogen dissociation and diffusion on Ni- and Ti-doped Mg,,0001... surfaces M. Pozzo,1,2 D. Alfè,1 functional theory investigation of hydrogen dissociation and surface diffusion over a Ni-doped surface show that the energy barrier for hydrogen dissociation on the pure Mg 0001 surface is high, while

  1. Ferromagnetism in Topochemically Prepared Layered Perovskite Li0.3Ni0.85La2Ti3O10

    E-Print Network [OSTI]

    Spinu, Leonard

    Ferromagnetism in Topochemically Prepared Layered Perovskite Li0.3Ni0.85La2Ti3O10 Doinita Neiner between the perovskite blocks of triple-layer Ruddlesden-Popper titanate Li2La2Ti3O10 by ion exchange

  2. Experimental study of the FeNiTi system L.I. Duarte a,b,*, U.E. Klotz a,1

    E-Print Network [OSTI]

    Giger, Christine

    system, which is relevant for many different materials such as steels, Ni-based superalloys, alloyed a mixture of Ni and Ti powders on an iron substrate and annealing at 1100, 1200 and 1250 C for 5­120 min

  3. Structure and magnetic properties of Ce?(Ni/Al/Ga)??—A new phase with the La?Al?? structure type

    SciTech Connect (OSTI)

    Janka, Oliver; Shang, Tian; Baumbach, Ryan E.; Bauer, Eric D.; Thompson, Joe D.; Kauzlarich, Susan M.

    2015-03-01

    Single crystals of Ce?(Ni/Al/Ga)?? were obtained from an Al flux reaction. Single crystals of the title compound crystallizing in the orthorhombic space group Immm (No. 71, Z = 2) with a = 436.38(14), b = 1004.5(3) and c = 1293.4(4) pm. This is a standardized unit cell of the previously published La?Al?? structure type. Wavelength dispersive microprobe provides the composition of Ce?.?????Ni?.?????Al?.?????Ga?.?????. Single crystal refinement provides the composition Ce?Ni?.??Al?.??Ga?.?? with substitution of the Ni and Ga on the Al1 and Al4 sites with the Al2 and Al3 solely occupied by Al. Magnetic susceptibility measurements reveal antiferromagnetic ordering with TN = 4.8 K and there is no evidence for a ferromagnetic ordering that has been reported for Ce?Al??. The effective magnetic moment was found to be ?eff = 1.9?B/Ce, which is lower than the expected value for trivalent Ce (2.54?B/Ce).

  4. HIGH-TEMPERATURE FRACTURE AND FATIGUE RESISTANCE OF A DUCTILE b-TiNb REINFORCED g-TiAl

    E-Print Network [OSTI]

    Ritchie, Robert

    are in part aimed at improving their low room-temperature ten- sile ductility and fracture toughness, bothHIGH-TEMPERATURE FRACTURE AND FATIGUE RESISTANCE OF A DUCTILE b-TiNb REINFORCED g the fracture toughness of g-TiAl, even at high temperatures, from about 12 to H40 MPa m1/2 , although

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

    E-Print Network [OSTI]

    Cao, Guozhong

    bottoms, and turbochargers.1 However, Al2TiO5 materials have a relatively low mechanical strength because

  6. Formation and Stability of Ni-Al Hydroxide Phases in Soils

    E-Print Network [OSTI]

    Sparks, Donald L.

    surface precipitate phases on kaolinite surfaces as the humic acid content of the system was increased. At 1% humic acid by weight, mixed Ni-Al hydroxide precipitates formed on the kaolinite surface after 4 days. At 5 wt % humic acid, however, precipitate formation was slower and resulted in Ni(OH)2

  7. Shape memory and superelasticity in polycrystalline Cu-Al-Ni microwires

    E-Print Network [OSTI]

    Chen, Ying

    We report a strategy to significantly improve the ductility and achieve large superelastic and shape memory strains in polycrystalline Cu–Al–Ni shape memory alloys that are normally brittle. We use a liquid-phase (Taylor) ...

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

    SciTech Connect (OSTI)

    Teng, Zhenke; Zhang, F; Miller, Michael K; Liu, Chain T; Huang, Shenyan; Chou, Y.T.; Tien, R; Chang, Y A; Liaw, Peter K

    2012-01-01

    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.

  9. Shape-Memory Transformations of NiTi: Minimum-Energy Pathways between Austenite, Martensites, and Kinetically Limited Intermediate States

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

    Zarkevich, N. A.; Johnson, D. D.

    2014-12-24

    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, butmore »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.« less

  10. A protocol to develop crack-free biomimetic coatings on Ti6Al4V substrates

    E-Print Network [OSTI]

    Tas, A. Cuneyt

    A protocol to develop crack-free biomimetic coatings on Ti6Al4V substrates Sahil Jalota,a) Sutapa/Kadikoy, Istanbul 34755, Turkey (Received 22 November 2006; accepted 16 February 2007) Biomimetic coating in implantology. While this paper specifically refers to coating Ti6Al4V, the results are valid with other related

  11. Irradiation-induced disordering and amorphization of Al3Ti-based intermetallic compounds

    E-Print Network [OSTI]

    Motta, Arthur T.

    Irradiation-induced disordering and amorphization of Al3Ti-based intermetallic compounds Jeong October 2015 Accepted 19 October 2015 Available online 21 October 2015 a b s t r a c t An in situ ion-irradiation irradiation-induced disordering and amorphization of Al3Ti-based intermetallic compounds. Thin foil samples

  12. Processing and Mechanical Properties of Ti2AlC Reinforced with Alumina Fibers 

    E-Print Network [OSTI]

    Jeon, Kwonguk

    2012-10-19

    The fabrication and mechanical properties of Ti2AlC composites reinforced with the alumina oxide fibers, such as NextelTM 720 and ALBF1, were described in this thesis. Alumina fibers and Ti2AlC powders were dispersed in the water and slip cast...

  13. Crystallization and phase transformations in amorphous NiTi thin films for microelectromechanical systems

    SciTech Connect (OSTI)

    Lee, Hoo-Jeong; Ramirez, Ainissa G. [Department of Mechanical Engineering, Yale University, New Haven, Connecticut 06520 (United States)

    2004-08-16

    Amorphous sputtered nickel-titanium thin films were deposited onto micromachined silicon-nitride membranes and subjected to heating and cooling conditions. Their associated microstructure was monitored directly and simultaneously with in situ transmission electron microscopy. These electron-transparent membranes constrained the NiTi films and rendered it possible for observation of the complete transformation cycle, which includes: the crystallization of the amorphous phase to austenite phase (cubic B2 structure) with heating; and the conversion of austenite (B2) to martensite (monoclinic B19{sup '} structure) with cooling. Electron micrographs show the nucleation and growth of grains occurs at a temperature of 470 deg. C and at a rate that indicates a polymorphic transformation. The onset of martensitic transformation occurs between 25 and 35 deg. C. Calorimetric measurements are consistent with the observed crystallization.

  14. An Experimental and Theoretical Multi-Mbar Study of Ti-6Al-4V

    SciTech Connect (OSTI)

    Tegner, B E; Macleod, S G; CYNN, H; Proctor, J; Evans, W J; McMahon, M I; Ackland, G J

    2011-04-13

    We report results from an experimental and theoretical study of the room temperature (RT) compression of the ternary alloy Ti-6Al-4V. In this work, we have extended knowledge of the equation of state (EOS) from 40 GPa to 221 GPa, and observed a different sequence of phase transitions to that reported previously for pure Ti.

  15. Synthesis of nanocrystalline aluminum matrix composites reinforced with in situ devitrified Al-Ni-La amorphous particles

    E-Print Network [OSTI]

    Zhang, Zhihui H; Han, B Q; Witkin, D; Ajdelsztajn, L; Laverna, E J

    2006-01-01

    metals, RE = rare earth metals) alloys [4] provides a newwith Al and Ni, the rare earth metal La, however, has the

  16. Activity and structure of hydrotreating Ni, Mo, and Ni-Mo sulfide catalysts supported on {gamma}-Al{sub 2}O{sub 3}--USY zeolite

    SciTech Connect (OSTI)

    Li, D.; Nishijima, A.; Morris, D.E.; Guthrie, G.D.

    1999-11-15

    The catalytic hydrocracking (HC) of diphenylmethane (DPM) and hydrodesulfurization (HDS) of dibenzothiophene (DBT) over Ni, Mo, and Ni-Mo sulfide catalysts supported on a mixed ultrastable Y (USY) zeolite and gamma-Al{sub 2}O{sub 3} were studied. The catalysts were characterized using NH{sub 3} temperature-programmed desorption (TPD), X-ray photoelectron spectroscopy (XPS), UV-Vis-NIR diffuse reflectance spectroscopy (DRS), high-resolution transmission electron microscopy (HRTEM), and chemical composition analysis. Because addition of zeolite to a conventional alumina support improves acidity, Ni, Mo, and Ni-Mo catalysts supported on the combined supports had much higher HC activity. Ni was found to be uniformly distributed throughout the catalysts; however, Mo preferentially entered the structure of {gamma}-Al{sub 2}O{sub 3} or was accommodated as oxide aggregates on {gamma}-Al{sub 2}O{sub 3}, rather than associating with zeolite. Ni and Mo catalysts supported on {gamma}-Al{sub 2}O{sub 3}-USY zeolite were good HDS catalysts and showed a shallow maximum in catalytic activity at a NiO and MoO{sub 3} content of 5 mol%. The higher activity at this content occurred because Ni or Mo species had higher surface concentrations, higher dispersion, and were more easily sulfided. Ni-Mo catalysts supported on {gamma}-Al{sub 2}O{sub 3}-USY zeolite had high HDS activity, which showed a prominent maximum at a NiO/(NiO + MoO{sub 3}) ratio of about 0.4, because at this ratio the surface species of Ni and Mo were well dispersed and more easily sulfided to form a Ni-Mo-S phase responsible for the high HDS activity. The Ni-Mo catalysts supported on gamma-Al{sub 2}O{sub 3}-USY zeolite have slightly higher HDS activity than {gamma}-Al{sub 2}O{sub 3}-USY zeolite have slightly higher HDS activity than {gamma}-Al{sub 2}O{sub 3}-supported Ni-Mo catalysts.

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

    DOE Patents [OSTI]

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

    2002-01-01

    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.

  18. Process for producing Ti-Cr-Al-O thin film resistors

    DOE Patents [OSTI]

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

    2001-01-01

    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.

  19. Adhesion strength of sputtered TiAlN-coated WC insert tool

    SciTech Connect (OSTI)

    Budi, Esmar; Razali, M. Mohd.; Nizam, A. R. Md.

    2013-09-09

    The adhesion strength of TiAlN coating that deposited by using DC magnetron sputtering on WC insert tool are studied. TiAlN coating are deposited on Tungsten Carbide (WC) insert tool by varying negatively substrate bias from 79 to 221 volt and nitrogen flow rate from 30 to 72 sccm. The adhesion strength are obtained by using Rockwell indentation test method with a Brale diamond at applied load of 60,100 and 150 kgf. The lateral diameter of indentation is plotted on three different applied loads and the adhesion strength of TiAlN coating was obtained from the curved slopes at 100 and 150 kgf. The lower curve slop indicated better adhesion strength. The results shows that the adhesion strength of sputterred TiAlN coating tend to increase as the negatively substrate bias and nitrogen flow rate are increased.

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

    E-Print Network [OSTI]

    Ciobanu, Cristian

    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

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

    E-Print Network [OSTI]

    Pennycook, Steve

    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 structural models have been proposed for de- cagonal quasicrystals based upon x-ray and neutron diffrac- tion

  2. Ni3Al-based alloys for die and tool application

    DOE Patents [OSTI]

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

    2001-01-01

    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.

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

    DOE Patents [OSTI]

    Liu, Chain T. (Oak Ridge, TN)

    2000-01-01

    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.

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

    SciTech Connect (OSTI)

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

    1996-12-31

    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.

  5. Aging effects in palladium and LaNi sub 4. 25 Al sub 0. 75 tritides

    SciTech Connect (OSTI)

    Nobile, A.; Wermer, J.R.; Walters, R.T.

    1991-01-01

    Palladium and LaNi{sub 5-x}Al{sub x} (x=0.30, 0.75, 0.85), which form reversible hydrides, are used for tritium processing and storage in the Savannah River Site (SRS) tritium facilities. As part of a program to develop technology based on the use of reversible metal hydrides for tritium processing and storage, the effects of aging on the thermodynamic behavior of palladium and LaNi{sub 4.25}Al{sub 0. 75} tritides are under investigation. During aging, the {sup 3}He tritium decay product remains in the tritide lattice and changes the thermodynamics of the tritium-metal tritide system. Aging effects in 755-day-aged palladium and 1423-day-aged LaNi{sub 4.25}Al{sub 0.75} tritides will be reported. Changes in the thermodynamics were determined by measuring tritium desorption isotherms on aging samples. In palladium, aging decreases the desorption isotherm plateau pressure and changes the {alpha}-phase portion of the isotherm. Aging-induced changes in desorption isotherms are more drastic in LaNi{sub 4.25}Al{sub 0.75}. Among the changes noted are: (1) decreased isotherm plateau pressure, (2) increased isotherm plateau slope, and (3) appearance of deep-trapped tritium, removable only by exchange with deuterium.

  6. Rapid Laser Induced Crystallization of Amorphous NiTi Films Observed by Nanosecond Dynamic Transmission Electron Microscopy (DTEM)

    SciTech Connect (OSTI)

    LaGrange, T; Campbell, G H; Browning, N D; Reed, B W; Grummon, D S

    2010-03-01

    The crystallization processes of the as-deposited, amorphous NiTi thin films have been studied in detail using techniques such as differential scanning calorimetry and, in-situ TEM. The kinetic data have been analyzed in terms of Johnson-Mehl-Avrami-Kolomogrov (JMAK) semi-empirical formula. The kinetic parameters determined from this analysis have been useful in defining process control parameters for tailoring microstructural features and shape memory properties. Due to the commercial push to shrink thin film-based devices, unique processing techniques have been developed using laser-based annealing to spatially control the microstructure evolution down to sub-micron levels. Nanosecond, pulse laser annealing is particularly attractive since it limits the amount of peripheral heating and unwanted microstructural changes to underlying or surrounding material. However, crystallization under pulsed laser irradiation can differ significantly from conventional thermal annealing, e.g., slow heating in a furnace. This is especially true for amorphous NiTi materials and relevant for shape memory thin film based microelectromechanical systems (MEMS) applications. There is little to no data on the crystallization kinetics of NiTi under pulsed laser irradiation, primarily due to the high crystallization rates intrinsic to high temperature annealing and the spatial and temporal resolution limits of standard techniques. However, with the high time and spatial resolution capabilities of the dynamic transmission electron microscope (DTEM) constructed at Lawrence Livermore National Laboratory, the rapid nucleation events occurring from pulsed laser irradiation can be directly observed and nucleation rates can be quantified. This paper briefly explains the DTEM approach and how it used to investigate the pulsed laser induced crystallization processes in NiTi and to determine kinetic parameters.

  7. Microstructure–property relationships in a high-strength 51Ni–29Ti–20Hf shape memory alloy

    SciTech Connect (OSTI)

    Coughlin, D. R.; Casalena, L.; Yang, F.; Noebe, R. D.; Mills, M. J.

    2015-09-18

    NiTiHf alloys exhibit remarkable shape memory and pseudoelastic properties that are of fundamental interest to a growing number of industries. In this study, differential scanning calorimetry and isothermal compression tests have revealed that the 51Ni–29Ti–20Hf alloy has useful shape memory properties that include a wide range of transformation temperatures as well as highly stable pseudoelastic behavior. These properties are governed by short-term aging conditions, which may be tailored to control transformation temperatures while giving rise to exceptionally high austenite yield strengths which aid transformation stability. The yield strength of the austenite phase can reach 2.1 GPa by aging for 3hrs at 500°C, while aging for 3hrs at 700°C produced an alloy with an austenite finish temperature (A f ) of 146°C. High-resolution scanning transmission electron microscopy has revealed a new precipitate phase, H-phase, under the homogenized and extruded condition and the aged 3 hrs at 500°C condition, but only the previously identified H-phase precipitate was observed after aging at temperatures of 600°C and 700°C for 3 hrs. Finally, dislocation analysis indicated that plastic deformation of the austenite phase occurred by <100> type slip, similar to that observed in binary NiTi.

  8. Microstructure–property relationships in a high-strength 51Ni–29Ti–20Hf shape memory alloy

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

    Coughlin, D. R.; Casalena, L.; Yang, F.; Noebe, R. D.; Mills, M. J.

    2015-09-18

    NiTiHf alloys exhibit remarkable shape memory and pseudoelastic properties that are of fundamental interest to a growing number of industries. In this study, differential scanning calorimetry and isothermal compression tests have revealed that the 51Ni–29Ti–20Hf alloy has useful shape memory properties that include a wide range of transformation temperatures as well as highly stable pseudoelastic behavior. These properties are governed by short-term aging conditions, which may be tailored to control transformation temperatures while giving rise to exceptionally high austenite yield strengths which aid transformation stability. The yield strength of the austenite phase can reach 2.1 GPa by aging for 3hrsmore »at 500°C, while aging for 3hrs at 700°C produced an alloy with an austenite finish temperature (A f ) of 146°C. High-resolution scanning transmission electron microscopy has revealed a new precipitate phase, H-phase, under the homogenized and extruded condition and the aged 3 hrs at 500°C condition, but only the previously identified H-phase precipitate was observed after aging at temperatures of 600°C and 700°C for 3 hrs. Finally, dislocation analysis indicated that plastic deformation of the austenite phase occurred by type slip, similar to that observed in binary NiTi.« less

  9. Industrial Application of Thin Films (TiAl)N Deposited on Thermo-Wells

    SciTech Connect (OSTI)

    Velez, G.; Jaramillo, S.; Arango, Y. C.; Devia, D.; Quintero, J.; Devia, A.

    2006-12-04

    The thermo-well is formed by two layers, one layer is a ceramic and the other layer is anviloy (comprised tungsten). They are used to coat the thermocouple in the control temperature system during the Aluminum-Silicon alloy melting process. After two weeks of continuous work at 750 deg. C of temperature (the alloy temperature), a high wear in this material is observed, affecting the ceramic. (TiAl)N thin films are deposited directly on the anviloy substrates by the PAPVD (Plasma Assisted Physics Vapor Deposition) in arc pulsed technique, using a TiAl target in a mono-vaporizer system, composed by a reactor and a power controlled system. Two opposite electrodes are placed into the reactor and discharge is produced by a controlled power system. The XRD (X-ray diffraction) patterns show the presence of the (TiAl)N thin film peaks. The morphological characteristics are studied by the scanning probe microscopy (SPM)

  10. Thermo-mechanical processing (TMP) of Ti-48Al-2Nb-2Cr based alloys

    SciTech Connect (OSTI)

    Fuchs, G.E.

    1995-02-01

    The effects of heat treatment and deformation processing on the microstructures and properties of {gamma}-TiAl based alloys produced by ingot metallurgy (I/M) and powder metallurgy (P/M) techniques were examined. The alloy selected for this work is the second generation {gamma}-TiAl based alloy -- Ti-48Al-2Nb-2Cr (at %). Homogenization of I/M samples was performed at a variety of temperatures, followed by hot working by isothermal forging. P/M samples were prepared from gas atomized powders, consolidated by both HIP and extrusion and some of the HIPed material was then hot worked by isothermal forging. The effects of processing, heat treatment and hot working on the microstructures and properties will be discussed.

  11. Improving the phase stability and oxidation resistance of B-NiAl

    SciTech Connect (OSTI)

    Brammer, Travis

    2011-08-15

    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

  12. Numerical prediction of the thermodynamic properties of ternary Al-Ni-Hf alloys

    SciTech Connect (OSTI)

    Romanowska, Jolanta; Kotowski, S?awomir; Zagula-Yavorska, Maryana

    2014-10-06

    Thermodynamic properties of ternary Al-Hf-Ni system, such as {sup ex}G, ?{sub Al}, ?{sub Ni} and ?{sub Zr} at 1373K were predicted on the basis of thermodynamic properties of binary systems included in the investigated ternary system. The idea of predicting {sup ex}G values was regarded as the calculation of excess Gibbs energy values inside a certain area (a Gibbs triangle) unless all boundary conditions, that is values of {sup ex}G on all legs of the triangle are known. {sup ex}G and L{sub ijk} ternary interaction parameters in the Muggianu extension of the Redlich-Kister formalism are calculated numerically using Wolfram Mathematica 9 software.

  13. Interfacial shear strength of cast and directionally solidified NiAl-sapphire fiber composites

    SciTech Connect (OSTI)

    Tewari, S.N.; Asthana, R. . Chemical Engineering Dept.); Noebe, R.D. . Intermetallics Branch)

    1993-09-01

    The feasibility of fabricating intermetallic NiAl-sapphire fiber composites by casting and zone directional solidification has been examined. The fiber-matrix interfacial shear strengths measured using a fiber push-out technique in both cast and directionally solidified composites are greater than the strengths reported for composites fabricated by powder cloth process using organic binders. Microscopic examination of fibers extracted from cast, directionally solidified (DS), and thermally cycled composites, and the high values of interfacial shear strengths suggest that the fiber-matrix interface does not degrade due to casting and directional solidification. Sapphire fibers do not pin grain boundaries during directional solidification, suggesting that this technique can be used to fabricate sapphire fiber reinforced NiAl composites with single crystal matrices.

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

    SciTech Connect (OSTI)

    Nan Mu

    2007-12-01

    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.%.

  15. Microstructure and mechanical properties of Ti/AlTiN/Ti-diamondlike carbon composite coatings on steel

    E-Print Network [OSTI]

    Volinsky, Alex A.

    for cutting tools.1­3 Some of these have already been applied in selected cases in modern machining techniquesTiN coating on hardened or austenitic stainless steels has been proven to improve cutting performance in heavy duty machining. These improvements were observed in different cutting operations due to the coat- ing

  16. Isothermal oxidation behavior and microstructure of plasma surface Ta coating on ?-TiAl

    SciTech Connect (OSTI)

    Song, Jian; Zhang, Ping-Ze Wei, Dong-Bo; Wei, Xiang-Fei; Wang, Ya

    2014-12-15

    The oxidation behavior of ?-TiAl with Ta surface coating fabricated by double glow plasma surface alloying technology was investigated by thermogravimetric method. Oxidation experiments were carried out at 750 °C and 850 °C in air for 100 h. The modification layer was comprised of deposition layer and diffusion layer, which metallurgically adhered to the substrate. Tantalum element decreased with the case depth. The oxidation morphology was studied by a scanning electron microscope and X-ray diffraction. The results highlighted that in the oxidizing process of the oxidation, the phase containing Ta-richer may restrain diffusing outward of the element Al in the matrix. Ti diffused outward, and formed the TiO{sub 2} scales, while the middle layer was rich in Al, and formed the continuous Al{sub 2}O{sub 3} scales after oxidation, which was effective to prevent further infiltration of oxygen atoms, and as a result the oxidation resistance increased immensely. - Highlights: • A Ta modified coating was prepared on ?-TiAl using DGP surface alloying technology. • The modification layer metallurgically adhered to the substrate. • The bonding force is about 60 N, satisfying the demands of practical use. • The oxidation resistance increased immensely at 750 °C and 850 °C.

  17. Influence of Cr and W alloying on the fiber-matrix interfacial shear strength in cast and directionally solidified sapphire NiAl composites

    SciTech Connect (OSTI)

    Asthana, R.; Tiwari, R.; Tewari, S.N.

    1995-08-01

    Sapphire-reinforced NiAl matrix composites with chromium or tungsten as alloying additions were synthesized using casting and zone directional solidification (DS) techniques and characterized by a fiber pushout test as well as by microhardness measurements. The sapphire-NiAl(Cr) specimens exhibited an interlayer of Cr rich eutectic at the fiber-matrix interface and a higher interfacial shear strength compared to unalloyed sapphire-NiAl specimens processed under identical conditions. In contrast, the sapphire-NiAl(W) specimens did not show interfacial excess of tungsten rich phases, although the interfacial shear strength was high and comparable to that of sapphire-NiAl(Cr). The postdebond sliding stress was higher in sapphire-NiAl(Cr) than in sapphire-NiAl(W) due to interface enrichment with chromium particles. The matrix microhardness progressively decreased with increasing distance from the interface in both DS NiAl and NiAl(Cr) specimens. The study highlights the potential of casting and DS techniques to improve the toughness and strength of NiAl by designing dual-phase microstructures in NiAl alloys reinforced with sapphire fibers.

  18. Process Modeling of Ti-6Al-4V Linear Friction Welding (LFW)

    E-Print Network [OSTI]

    Grujicic, Mica

    Process Modeling of Ti-6Al-4V Linear Friction Welding (LFW) Mica Grujicic, G. Arakere, B finite-element analysis of the linear friction welding (LFW) process is combined with the basic physical in the open literature revealed that the weld region consists of a thermo- mechanically affected zone (TMAZ

  19. Thermal protection of H13 steel by growth of (TiAl)N films by PAPVD pulsed arc technique

    SciTech Connect (OSTI)

    Jimenez, H.; Devia, D.M.; Benavides, V.; Devia, A. Arango, Y.C.; Arango, P.J.; Velez, J.M.

    2008-08-15

    (TiAl)N Films were grown on H13 steel by a plasma assisted repetitive pulsed arc discharge. To grow the coatings, a TiAl sintered cathode was used, 50% Ti-50% Al. The deposition system consists of a reaction chamber with two electrodes placed face to face. A pulsed power supply, which allows for control of parameters like time active arc, time between arcs, arc energy, and others, is used to generate the discharge. Thermal changes were carried out on H13 steel before and after growing the (TiAl)N films. X-ray diffraction (XRD) was employed to study the coatings, observing the H13 steel and (TiAl)N oxidation temperature. Morphological characteristics were analyzed by means of an Atomic Force Microscopy (AFM). Scanning electron microscopy (SEM) revealed the surface chemical composition of the films and morphological details of the samples.

  20. Locality and rapidity of the ultra-large elastic deformation of Nb nanowires in a NiTi phase-transforming matrix

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

    Wang, Shan; Cui, Lishan; Hao, Shijie; Jiang, Daqiang; Liu, Yinong; Liu, Zhenyang; Mao, Shengcheng; Han, Xiaodong; Ren, Yang

    2014-10-24

    This study investigated the elastic deformation behaviour of Nb nanowires embedded in a NiTi matrix. The Nb nanowires exhibited an ultra-large elastic deformation, which is found to be dictated by the martensitic transformation of the NiTi matrix, thus exhibiting unique characteristics of locality and rapidity. These are in clear contrast to our conventional observation of elastic deformations of crystalline solids, which is a homogeneous lattice distortion with a strain rate controlled by the applied strain. The Nb nanowires are also found to exhibit elastic-plastic deformation accompanying the martensitic transformation of the NiTi matrix in the case when the transformation strainmore »of the matrix over-matches the elastic strain limit of the nanowires, or exhibit only elastic deformation in the case of under-matching. Such insight provides an important opportunity for elastic strain engineering and composite design.« less

  1. Locality and rapidity of the ultra-large elastic deformation of Nb nanowires in a NiTi phase-transforming matrix

    SciTech Connect (OSTI)

    Wang, Shan; Cui, Lishan; Hao, Shijie; Jiang, Daqiang; Liu, Yinong; Liu, Zhenyang; Mao, Shengcheng; Han, Xiaodong; Ren, Yang

    2014-10-24

    This study investigated the elastic deformation behaviour of Nb nanowires embedded in a NiTi matrix. The Nb nanowires exhibited an ultra-large elastic deformation, which is found to be dictated by the martensitic transformation of the NiTi matrix, thus exhibiting unique characteristics of locality and rapidity. These are in clear contrast to our conventional observation of elastic deformations of crystalline solids, which is a homogeneous lattice distortion with a strain rate controlled by the applied strain. The Nb nanowires are also found to exhibit elastic-plastic deformation accompanying the martensitic transformation of the NiTi matrix in the case when the transformation strain of the matrix over-matches the elastic strain limit of the nanowires, or exhibit only elastic deformation in the case of under-matching. Such insight provides an important opportunity for elastic strain engineering and composite design.

  2. Tribological properties of self-lubricating NiAl/Mo-based composites containing AgVO{sub 3} nanowires

    SciTech Connect (OSTI)

    Liu, Eryong; Gao, Yimin; Bai, Yaping; Yi, Gewen; Wang, Wenzhen; Zeng, Zhixiang; Jia, Junhong

    2014-11-15

    Silver vanadate (AgVO{sub 3}) nanowires were synthesized by hydrothermal method and self-lubricating NiAl/Mo-AgVO{sub 3} composites were fabricated by powder metallurgy technique. The composition and microstructure of NiAl/Mo-based composites were characterized and the tribological properties were investigated from room temperature to 900 °C. The results showed that NiAl/Mo-based composites were consisted of nanocrystalline B2 ordered NiAl matrix, Al{sub 2}O{sub 3}, Mo{sub 2}C, metallic Ag and vanadium oxide phase. The appearance of metallic Ag and vanadium oxide phase can be attributed to the decomposition of AgVO{sub 3} during sintering. Wear testing results confirmed that NiAl/Mo-based composites have excellent tribological properties over a wide temperature range. For example, the friction coefficient and wear rate of NiAl/Mo-based composites containing AgVO{sub 3} were significantly lower than the composites containing only metallic Mo or AgVO{sub 3} lubricant when the temperature is above 300 °C, which can be attributed to the synergistic lubricating action of metallic Mo and AgVO{sub 3} lubricants. Furthermore, Raman results indicated that the composition on the worn surface of NiAl-based composites was self-adjusted after wear testing at different temperatures. For example, Ag{sub 3}VO{sub 4} and Fe{sub 3}O{sub 4} lubricants were responsible for the improvement of tribological properties at 500 °C, AgVO{sub 3}, Ag{sub 3}VO{sub 4} and molybdate for 700 °C, and AgVO{sub 3} and molybdate for 900 °C of NiAl-based composites with the addition of metallic Mo and AgVO{sub 3}. - Highlights: • NiAl/Mo-AgVO{sub 3} nanocomposites were prepared by mechanical alloying and sintering. • AgVO{sub 3} decomposed to metallic Ag and vanadium oxide during the sintering process. • NiAl/Mo-AgVO{sub 3} exhibited superior tribological properties at a board temperature range. • Phase composition on the worn surface was varied with temperatures. • Self-adjusted action was responsible for the improvement of tribological properties.

  3. Processing, properties, and wear resistance of aluminides. [Fe[sub 3]Al; Al[sub 3]Ti

    SciTech Connect (OSTI)

    Wright, R.N.; Rabin, B.H.; Wright, J.K.

    1993-03-01

    Fully dense alloys based on Fe[sub 3]Al were produced by reaction synthesis from low cost elemental powders using hot pressing, hot isostatic pressing or Ceracon process. The reaction proceeds by outward spreading of a transient liquid phase from the initial aluminum particle site and precipitation of the compound phase from the liquid. Combustion synthesized material has a very fine grain size that is resistant to coarsening at high temperature because of a high density of fine oxides from the prior particle boundaries. The fine grain size results in approximately twice the yield strength in the reaction synthesized material compared to hot extruded pre-alloyed powder. Combustion synthesis has also been successfully applied to joining Fe[sub 3]Al and to forming coatings on carbon steel substrates. Combustion synthesis has been shown to be viable for fabricating trialuminides from elemental powder compacts. Al[sub 3]Ti, Al[sub 73]Ti[sub 24]Cr[sub 3] and Al[sub 67]Ti[sub 25]Cr[sub 8] were examined. Fully dense, homogeneous materials exhibiting an equiaxed grain structure were produced by conducting reaction and homogenization under pressure, or in a furnace at ambient pressure and subsequently densifying the porous preform by hot consolidation. The tetragonal DO[sub 22] structure was the primary reaction product for all compositions. Most of the Cr remained undissolved after reaction and a homogenization heat treatment at 1200C or above was used to put the Cr into solution and form the desired L1[sub 2] phase.

  4. Influence of the Al distribution on the structure, elastic properties, and phase stability of supersaturated Ti{sub 1-x}Al{sub x}N

    SciTech Connect (OSTI)

    Mayrhofer, P. H.; Music, D.; Schneider, J. M.

    2006-11-01

    Ti{sub 1-x}Al{sub x}N films and/or their alloys are employed in many industrial applications due to their excellent mechanical and thermal properties. Synthesized by plasma-assisted vapor deposition, Ti{sub 1-x}Al{sub x}N is reported to crystallize in the cubic NaCl (c) structure for AlN mole fractions below 0.4-0.91, whereas at larger Al contents the hexagonal ZnS-wurtzite (w) structure is observed. Here we use ab initio calculations to analyze the effect of composition and Al distribution on the metal sublattice on phase stability, structure, and elastic properties of c-Ti{sub 1-x}Al{sub x}N and w-Ti{sub 1-x}Al{sub x}N. We show that the phase stability of supersaturated c-Ti{sub 1-x}Al{sub x}N not only depends on the chemical composition but also on the Al distribution of the metal sublattice. An increase of the metastable solubility limit of AlN in c-Ti{sub 1-x}Al{sub x}N from 0.64 to 0.74 is obtained by decreasing the number of Ti-Al bonds. This can be understood by considering the Al distribution induced changes of the electronic structure, bond energy, and configurational entropy. This may in part explain the large variation of the metastable solubility limit reported in the literature.

  5. Environmental effect on room-temperature ductility of isothermally forged TiAl-base alloys

    SciTech Connect (OSTI)

    Nakamura, Morihiko; Hashimoto, Kenki (National Research Inst. for Metals, Tokyo (Japan)); Itoh, Naoyuki (Nippon Steel Corp., Chiba (Japan)); Tsujimoto, Tokuzo (Ibaraki Univ. (Japan). Faculty of Engineering); Suzuki, Toshiyuki (Kougakuin Univ., Tokyo (Japan))

    1994-02-01

    Isothermally forged TiAl-base alloy (Al-rich, Mn-containing, and Cr-containing TiAl) were heat-treated in various conditions, and equiaxed grain structures consisting of [gamma] and [alpha][sub 2] or [beta] phases were obtained. The heat-treated alloys were tensile tested in vacuum and air at room temperature, and the environmental effect on tensile elongation was studied. The ductility of the alloys consisting of equiaxed [gamma] grains and a large amount of [alpha][sub 2] grains was not largely affecting by laboratory air, and a decrease in the amount of [alpha][sub 2] grains resulted in a large reduction of ductility in air. The [beta] phase in the Cr-containing alloy improved the ductility in vacuum, but it resulted in a large reduction of ductility in air.

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

    E-Print Network [OSTI]

    Ritchie, Robert

    ; Ti±6Al±4V 1. Introduction The high-cycle fatigue (HCF) of aircraft gas-turbine engine components has-cycle fatigue of Ti±6Al±4V J.O. Peters, R.O. Ritchie * Department of Materials Science and Mineral Engineering of small surface fatigue cracks in a Ti±6Al±4V alloy, processed for typical turbine blade applications

  7. Role of B19' martensite deformation in stabilizing two-way shape memory behavior in NiTi

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

    Benafan, O.; Padula, S. A.; Noebe, R. D.; Sisneros, T. A.; Vaidyanathan, R.

    2012-11-01

    Deformation of a B19' martensitic, polycrystallineNi49.9Ti50.1 (at. %) shape memoryalloy and its influence on the magnitude and stability of the ensuing two-way shape memory effect (TWSME) was investigated by combined ex situ mechanical experimentation and in situneutron diffraction measurements at stress and temperature. The microstructural changes (texture, lattice strains, and phase fractions) during room-temperature deformation and subsequent thermal cycling were captured and compared to the bulk macroscopic response of the alloy. With increasing uniaxial strain, it was observed that B19' martensite deformed by reorientation and detwinning with preferred selection of the (1¯50)M and (010)M variants, (201¯)B19' deformation twinning, and dislocationmore »activity. These mechanisms were indicated by changes in bulk texture from the neutron diffraction measurements. Partial reversibility of the reoriented variants and deformation twins was also captured upon load removal and thermal cycling, which after isothermal deformation to strains between 6% and 22% resulted in a strong TWSME. Consequently, TWSME functional parameters including TWSME strain, strain reduction, and transformation temperatures were characterized and it was found that prior martensite deformation to 14% strain provided the optimum condition for the TWSME, resulting in a stable two-way shape memory strain of 2.2%. Thus, isothermal deformation of martensite was found to be a quick and efficient method for creating a strong and stable TWSME in Ni??.?Ti??.?.« less

  8. The effect of cooling rate during rapid solidification on the structure and texture of NiTi

    SciTech Connect (OSTI)

    Pedraza, A.J.; Godbole, M.J.; Kenik, E.A.; Pedraza, D.F.; Lowndes, D.H.

    1986-01-01

    A study has been conducted on the effects of increasing cooling rate during rapid solidification of NiTi upon the phases that are produced. The hammer and anvil rapid solidification technique and laser melting with a nanosecond excimer laser were used, which allow the cooling rate to be varied by three to four orders of magnitude. Although 1/3 (110) superlattice reflections are seen in the selected area diffraction (SAD) patterns of the splat quenched (SQ) specimens, x-ray diffraction analyses show the presence of only B2 phase and martensite. On the other hand, laser treatment (LT) of the specimens produces a layer that has a Ll/sub 0/ structure with a slight monoclinic distortion. This phase can be envisaged as a small distortion of a B2 unit cell with a volume per atom approx.3.3% lower than the equilibrium B2 phase. Also martensite is present in the layer. SQ alloys exhibited a marked (200) texture due to columnar growth opposite to the direction of heat extraction, while LT produces epitaxial regrowth of the melted layer. No substantial disordering is obtained in NiTi rapidly solidified alloys.

  9. Spin-dependent transport across Co/LaAlO{sub 3}/SrTiO{sub 3} heterojunctions

    SciTech Connect (OSTI)

    Swartz, Adrian G.; Harashima, Satoshi; Xie, Yanwu; Kim, Bongju; Hwang, Harold Y.; Lu, Di; Bell, Christopher; Hikita, Yasuyuki

    2014-07-21

    The conducting interface formed between LaAlO{sub 3} and SrTiO{sub 3} exhibits high electron mobility, tunable carrier densities, and is theoretically predicted to have long spin lifetimes. Thus, the LaAlO{sub 3}/SrTiO{sub 3} heterostructure is a promising system for the transportation of spin information. We have investigated spin-dependent transport across Co/LaAlO{sub 3}/SrTiO{sub 3} heterostructures using an all electrical three terminal geometry and observed Lorentzian magnetoresistance typically associated with Hanle spin dephasing. However, such a picture fails to explain all the experimentally observed behavior. Further, experiments with spin-unpolarized Au/LaAlO{sub 3}/SrTiO{sub 3} heterojunctions support an alternative scenario involving current modulation by spin-dependent transport through defect states in the LaAlO{sub 3} barrier.

  10. Characterization of Mg/Al butt joints welded by gas tungsten arc filling with Zn–29.5Al–0.5Ti filler metal

    SciTech Connect (OSTI)

    Liu, Fei; Wang, Hongyang; Liu, Liming, E-mail: liulm@dlut.edu.cn

    2014-04-01

    The multivariate alloying design of a welding joint is used in the Mg to Al welding process. A Zn–29.5Al–0.5Ti alloy is added as filler metal in gas tungsten arc welding of Mg and Al alloy joint based on the analysis of Al and Mg alloy characteristics. The tensile strength, microstructure, and phase constitution of the weld seam are analyzed. The formation of brittle and hard Mg–Al intermetallic compounds is avoided because of the effects of Zn, Al, and Ti. The average tensile strength of the joint is 148 MPa. Al{sub 3}Ti is first precipitated and functions as the nucleus of heterogeneous nucleation during solidification. Moreover, the precipitated Al–MgZn{sub 2} hypoeutectic phase exhibited a feather-like structure, which enhances the property of the Mg–Al dissimilar joint. - Highlights: • Mg alloy AZ31B and Al alloy 6061 are butt welded by fusion welding. • The effect of Ti in filler metal is investigated. • The formation of Mg–Al intermetallic compounds is avoided.

  11. Sessile dislocations by reactions in NiAl severely deformed at room temperature

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

    Geist, D.; Gammer, C.; Rentenberger, C.; Karnthaler, H. P.

    2015-02-05

    B2 ordered NiAl is known for its poor room temperature (RT) ductility; failure occurs in a brittle like manner even in ductile single crystals deforming by single slip. In the present study NiAl was severely deformed at RT using the method of high pressure torsion (HPT) enabling the hitherto impossible investigation of multiple slip deformation. Methods of transmission electron microscopy were used to analyze the dislocations formed by the plastic deformation showing that as expected dislocations with Burgers vector a(100) carry the plasticity during HPT deformation at RT. In addition, we observe that they often form a(110) dislocations by dislocationmore »reactions; the a(110) dislocations are considered to be sessile based on calculations found in the literature. It is therefore concluded that the frequently encountered 3D dislocation networks containing sessile a(110) dislocations are pinned and lead to deformation-induced embrittlement. In spite of the severe deformation, the chemical order remains unchanged.« less

  12. Influence of fabrication technique on the fiber pushout behavior in a sapphire-reinforced NiAl matrix composite

    SciTech Connect (OSTI)

    Asthana, R.; Bowman, R.R. . Materials Division); Tewari, S.N. )

    1995-01-01

    Directional solidification (DS) of powder-cloth'' (PC) processed sapphire-NiAl composites was carried out to examined the influence of fabrication technique on the fiber-matrix interfacial shear strength, measured using a fiber-pushout technique. The DS process replaced the fine, equiaxed NiAl grain structure of the PC composites with an oriented grain structure comprised of large columnar NiAl grains aligned parallel to the fiber axis, with fibers either completely engulfed within the NiAl grains or anchored at one to three grain boundaries. The load-displacement behavior during the pushout test exhibited an initial pseudoelastic'' response, followed by an inelastic'' response, and finally a frictional'' sliding response. The fiber-matrix interfacial shear strength and the fracture behavior during fiber pushout were investigated using an interrupted pushout test and fractography, as functions of specimen thickness and fabrication technique. The composites fabricated using the PC and the DS techniques had different matrix and interface structures and appreciably different interfacial shear strengths. In the DS composites, where the fiber-matrix interfaces were identical for all the fibers, the interfacial debond shear stresses were larger for the fibers embedded completely within the NiAl grains and smaller for the fibers anchored at a few grain boundaries. The matrix grain boundaries coincident on sapphire fibers were observed to be the preferred sties for crack formation and propagation.

  13. The Electrochemical Behavior and Surface Analysis of Ti49.6Ni45.1Cu5Cr0.3 Alloy for Orthodontic Usage

    E-Print Network [OSTI]

    Zheng, Yufeng

    : shape memory alloys; dental materials; Ni-Ti-Cu-Cr; electrochemical behavior; electrochemical impedance in various medical devi- ces, for example, dental archwire, endodontic file, orthope- dic instruments fluids has been reported,1 and the authors con- clude that nickel-containing dental alloys do not pose

  14. Improved magnetoelectric performance of the Ni-P/Ni/Pb(Zr,TiO)3 cylindrical layered composites

    E-Print Network [OSTI]

    Volinsky, Alex A.

    -metal layers into laminate composites of Terfenol-D and PZT. Using the flux concentration effect of MetglasH frequency in the Metglas layers laminated together with polyvinylidene- fluoride (PVDF) piezopolymer layers. Afterwards, Fang et al.16 obtained the ME coefficient of up to 21.5 V/cmÁOe for the Metglas/PVDF bilayered

  15. Calculations of structural, elastic, electronic, magnetic and phonon properties of FeNiMnAl by the first principles

    SciTech Connect (OSTI)

    U?ur, ?ule; ?yigör, Ahmet

    2014-10-06

    The electronic, elastic and dynamical properties of the quaternary alloy FeNiMnAl have been investigated using a pseudopotential plane wave method within the generalized gradient approximation (GGA). We determined the lattice parameters and the bulk modulus B. In addition, the elastic properties such as elastic constans (C{sub 11}, C{sub 12} and C{sub 44}), the shear modulus G, the young modulus E, the poisson's ratio ? and the B/G ratio are also given. The FeNiMnAl Heusler alloy exhibit a ferromagnetic half-metallic behavior with the total magnetic moment of 4.02 ?{sub B}. The phonon dispersion of FeNiMnAl has been performed using the density functional theory and the direct method with 2×2×2 supercell.

  16. Influence of fabrication technique and matrix alloying on the interfacial shear strength of sapphire-NiAl composites

    SciTech Connect (OSTI)

    Asthana, R.; Bowman, R.R.; Tewari, S.N.

    1994-12-31

    The influence of fabrication technique and alloying on the fiber matrix interfacial shear strength, measured using a fiber push-out technique, has been examined in sapphire fiber-reinforced NiAl matrix composites. The composites were fabricated using the powder-cloth (P-C) process, a casting process, and the zone directional solidification (DS) process. The NiAl matrix was alloyed with Cr, W or Yb. The results showed that, in general, cast and DS composites had higher interfacial shear strengths compared to the P-C composites containing binders. Neither matrix alloying nor casting and DS impaired the interface strength. The study highlights the potential of the DS process in designing dual-phase ductile microstructures in sapphire-reinforced NiAl alloys for improved toughness and strength.

  17. Electronic and mechanical properties of Zr{sub 2}TiAl: A first principles study

    SciTech Connect (OSTI)

    Reddy, P. V. Sreenivasa, E-mail: kanchana@iith.ac.in; Kanchana, V., E-mail: kanchana@iith.ac.in [Department of Physics, Indian Institute of Technology Hyderabad, Ordnance Factory Estate, Yeddumailaram-502205, Andhra Pradesh (India)

    2014-04-24

    First principles study of electronic and mechanical properties of ternary phase Zr{sub 2}TiAl intermetallic compound has been carried out by using full potential linear augmented plane wave (FP-LAPW) method. Our calculated lattice parameter is in good agreement with the experiment. We find the magnetic phase of the compound to be stable with a magnetic moment of 1.95 ?{sub B}. The major contribution to the total magnetic moment arises mainly from the Ti atom with the local magnetic moment of 1.22 ?{sub B}. From the density of states plots we find the Ti-d and Zr-d to dominate at the Fermi level (E{sub F}) with enhanced crystal field splitting and exchange splitting found in Ti. The mechanical stability of the compound is confirmed from the calculated elastic constants, and we find the compound to be ductile in nature from the calculated Pugh’s ratio and Cauchy’s pressure.

  18. Shell model description of Gamow-Teller strengths for $^{42}$Ti, $^{46}$Cr, $^{50}$Fe and $^{54}$Ni

    E-Print Network [OSTI]

    Kumar, Vikas; Hirsch, Jorge G

    2015-01-01

    A systematic shell model description of the experimental Gamow-Teller transition strength distributions in $^{42}$Ti, $^{46}$Cr, $^{50}$Fe and $^{54}$Ni is presented. These transitions have been recently measured via $\\beta$ decay of these $T_z$=-1 nuclei, produced in fragmentation reactions at GSI and also with ($^3${He},$t$) charge-exchange (CE) reactions corresponding to $T_z = + 1$ to $T_z = 0$ carried out at RCNP-Osaka. The calculations are performed in the $pf$ model space, using the GXPF1a and KB3G effective interactions. Qualitative agreement is obtained for the individual transitions, while the calculated summed transition strengths closely reproduce the observed ones.

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

    SciTech Connect (OSTI)

    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)

    2014-11-01

    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.

  20. Duplex precipitates and their effects on the room-temperature fracture behaviour of a NiAl-strengthened ferritic alloy

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

    Sun, Zhiqian; Song, Gian; Ilavsky, Jan; Liaw, Peter K.

    2015-03-23

    Duplex precipitates are presented in a NiAl-strengthened ferritic alloy. They were characterized by the ultra-small angle X-ray scattering and transmission electron microscope. Fine cooling precipitates with the size of several to tens of nanometres harden the matrix considerably at room temperature. Cracks are likely to initiate from precipitates, and coalesce and propagate quickly through the matrix due to the excessive hardening effect of cooling precipitates, which lead to the premature fracture of NiAl-strengthened ferritic alloys.

  1. Hetero-twin formation during growth of nano-scale Al-TiN composites - experimental and DFT studies

    SciTech Connect (OSTI)

    Bhattacharyya, Dhriti [Los Alamos National Laboratory; Liu, Xiang - Yang [Los Alamos National Laboratory; Hoagland, Richard G [Los Alamos National Laboratory; Misra, Amit [Los Alamos National Laboratory; Genc, A [MSE, OSU; Fraser, H L [MSE, OSU

    2009-01-01

    It is well known that high stacking fault energy metals such as Al do not form either growth twins or mechanical twins easily. Although mechanical twins in nanocrystalline Al have been observed under certain conditions, growth twins have never been observed. In this work, the authors report for the first time, through transmission electron microscopy (TEM), that Al layers, when deposited on TiN layers, tend to grow in a twin relationship to both the TiN layer and the underlying Al layer. The TiN layers assume the orientation of the Al layers below. Calculations using density functional theory (DFT) show that nitrogen termination in the {l_brace}111{r_brace} growth plane of the TiN layers favors the growth of twin oriented Al layers over these TiN layers. This finding provides a way to create a twin-modulated structure in Al with the inclusion of intermediate nm-scale layer of an ionic solid such as TiN. Al metal is resistant to twinning, as it has a high stacking fault energy (SFE) of > 150 mJ/m. Although twins have been observed in nano-scale grains of Al, and predicted by molecular dynamics (MD) simulations in conditions when the nanoscale grains are plastically deformed, no process or phenomenon has been reported yet in which the deposition of an intermediate layer of a different material phase causes the subsequent layer of Al to be deposited in the twin orientation. The authors show in this paper that it is possible to form Al layers in twin orientation to each other across polar TiN layers, if these are grown so that both the Al and TiN layers have a {l_brace}111{r_brace} surface as their growth front. Since the deposition of Al and TiN layers is used in the formation of diffusion barriers, and the mechanical properties of these nanoscale multilayers are also seen to be exceptional, it is important to investigate and understand their structure at the nanometer length scale, and thence to be able to control it. Moreover, these findings point out a method of introducing nano-scale twins in high SFE materials in general, and can potentially improve the properties of nano-layered materials.

  2. Composition, morphology and mechanical properties of sputtered TiAlN coating

    SciTech Connect (OSTI)

    Budi, Esmar; Razali, M. Mohd.; Nizam, A. R. Md.

    2014-03-24

    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.

  3. Characteristics of a new creep regime in polycrystalline NiAl

    SciTech Connect (OSTI)

    Raj, S.V.; Farmer, S.C. )

    1995-02-01

    Constant-load creep tests were conducted on fine-grained ([approximately]23 [mu]m) Ni-50.6 (at. pct) Al in the temperature range of 1,000 to 1,400 K. Power-law creep with a stress exponent, n [approx] 6.5, and an activation energy, Q[sub c] [approx] 290 kJ mol[sup [minus]1], was observed above 25 MPa, while a new mechanism with n [approx] 2 and Q[sub c] [approx] 100 kJ mol[sup [minus]1] dominates when [sigma] < 25 MPa, where [sigma] is the applied stress. A comparison of the creep behavior of fine- and course-grained NiAl established that the mechanism in the n [approx] 2 region was dependent on grain size, and the magnitude of the grain-size exponent was estimated to be about 2. Transmission electron microscopy (TEM) observations of the deformed specimens revealed a mixture of dislocation tangles, dipoles, loops, and subboundary networks in the power-law creep regime. The deformation microstructures were inhomogeneous in the n [approx] 2 creep regime, and many grains did not reveal any dislocation activity. However, bands of dislocation loops were observed in a few grains, where these loops appeared to have been emitted from the grain boundaries. The observed creep characteristics of the low-stress region suggest the dominance of an accommodated grain-boundary sliding (GBS) mechanism, although the experimental creep rates were lower than those predicted by theoretical models by over seven orders of magnitude. The low value of Q[sub c] in this region, which is approximately one-third that for lattice self-diffusion, is attributed to the possible existence of interconnected vacancy flow channels, or nanotubes'', at the grain boundaries.

  4. Materials Science and Engineering A 394 (2005) 4352 NiAl bond coats made by a directed vapor deposition approach

    E-Print Network [OSTI]

    Wadley, Haydn

    2005-01-01

    Materials Science and Engineering A 394 (2005) 43­52 NiAl bond coats made by a directed vapor materials in thermal barrier coating systems applied to nickel base super alloy components. They are usually to nickel base su- peralloy components used in gas turbine engines [1]. In these systems, a metallic bond

  5. Aging effects in palladium and LaNi{sub 4.25}Al{sub 0.75} tritides

    SciTech Connect (OSTI)

    Nobile, A.; Wermer, J.R.; Walters, R.T.

    1991-12-31

    Palladium and LaNi{sub 5-x}Al{sub x} (x=0.30, 0.75, 0.85), which form reversible hydrides, are used for tritium processing and storage in the Savannah River Site (SRS) tritium facilities. As part of a program to develop technology based on the use of reversible metal hydrides for tritium processing and storage, the effects of aging on the thermodynamic behavior of palladium and LaNi{sub 4.25}Al{sub 0. 75} tritides are under investigation. During aging, the {sup 3}He tritium decay product remains in the tritide lattice and changes the thermodynamics of the tritium-metal tritide system. Aging effects in 755-day-aged palladium and 1423-day-aged LaNi{sub 4.25}Al{sub 0.75} tritides will be reported. Changes in the thermodynamics were determined by measuring tritium desorption isotherms on aging samples. In palladium, aging decreases the desorption isotherm plateau pressure and changes the {alpha}-phase portion of the isotherm. Aging-induced changes in desorption isotherms are more drastic in LaNi{sub 4.25}Al{sub 0.75}. Among the changes noted are: (1) decreased isotherm plateau pressure, (2) increased isotherm plateau slope, and (3) appearance of deep-trapped tritium, removable only by exchange with deuterium.

  6. Simulation par la théorie de la fonctionnelle de la densité de l'interaction de l'ion uranyle avec les surfaces de $TiO_{2}$ et de $NiFe_{2}O_4$

    E-Print Network [OSTI]

    Perron, Hadrien

    2007-01-01

    Simulation par la théorie de la fonctionnelle de la densité de l'interaction de l'ion uranyle avec les surfaces de $TiO_{2}$ et de $NiFe_{2}O_4$

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

    SciTech Connect (OSTI)

    Bhattacharyya, Dhriti; Mara, Nathan A; Dickerson, Patricia O; Misra, Amit; Hoagland, R G

    2009-01-01

    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.

  8. Ab initio study of irradiation tolerance for different M{sub n+1}AX{sub n} phases: Ti{sub 3}SiC{sub 2} and Ti{sub 3}AlC{sub 2}

    SciTech Connect (OSTI)

    Zhao, Shijun; Xue, Jianming, E-mail: jmxue@pku.edu.cn; Wang, Yugang [State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871 (China); Center for Applied Physics and Technology, Peking University, Beijing 100871 (China); Huang, Qing [Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, Zhejiang (China)

    2014-01-14

    Layered ternary M{sub n+1}AX{sub n} (MAX) materials are recently proposed to be promising candidates for future fission and fusion programmes because of their unique properties inherited from both ceramics and metals. However, different M{sub n+1}AX{sub n} materials demonstrate different behaviors when exposed to energetic neutron or ion irradiations. Based on first-principles calculations, we have investigated the irradiation tolerance of two typical M{sub n+1}AX{sub n} materials: Ti{sub 3}SiC{sub 2} and Ti{sub 3}AlC{sub 2} from two aspects. First, we make a detailed analysis on the interatomic bonding characters, which are believed to be responsible for the resistance to radiation-induced amorphization. Second, the formation energies of various intrinsic and antisite defects in these two compounds are calculated in order to elucidate their amorphization mechanism. Our results show that the absence of orbitals overlap of Al-C in Ti{sub 3}AlC{sub 2} renders it more resistant to amorphization compared to Ti{sub 3}SiC{sub 2}. In addition, the antisite defects Al{sub Ti(1)} and Al{sub Ti(2)} in Ti{sub 3}AlC{sub 2} have much lower formation energies compared to Si{sub Ti(1)} and Si{sub Ti(2)} in Ti{sub 3}SiC{sub 2}, which implies that the replacement of Ti with Al is easier than Si, thus providing an alternative way to accommodate the defects resulted from irradiation damage cascades. These results indicate that Ti{sub 3}AlC{sub 2} is more irradiation tolerant than Ti{sub 3}SiC{sub 2}, in accordance with experimental observations. Our results have profound implications for the choice of appropriate MAX phase with best performance to be used in next reaction reactors.

  9. Characterization of Ti-6%Al-4%V and VascoMax C-350

    SciTech Connect (OSTI)

    Sunwoo, A J

    2005-02-07

    The {alpha}-{beta} Ti-6% Al-4% V (Ti64) alloy can be heat treated to meet the specified requirements of the applications. The as-received material from SLAC was given a solution heat treatment (SHT) to have a good strength and ductility combination. The SHT was done at 200 C below the Beta transus of 990 C for 15 min and air-cooled to 20 C. The designed microstructure consists of {beta} phase precipitates within the {alpha} phase matrix. The characterization of the as-received Ti64 alloy sheet microstructure reveals equiaxed, 10 {micro}m-sized grains on the flat surface and finer, 8 {micro}m-sized grains in the through thickness. Figures 1 and 2 show the microstructure of the alloy. The typical Ti64 microstructure is lamellar structure, consisting of alternating {alpha} and {beta} phases. In order for the alloy to have the micron sized, equiaxed grains, it had to undergo extensive wrought processing. The Vicker's microhardness numbers (VHN) showed that the slightly larger grained flat surface had a higher averaged value than the through thickness; 33 kg/mm{sup 2} vs. 30 kg/mm{sup 2}. The residual effect of wrought processing is still present even after the SHT to cause the small difference in the hardness values. The results of tensile tests conducted at LLNL and at BNL are given in Tables 2 and 1 in Appendices 1 and 2, respectively. The effects of the irradiation dosage damage on the tensile properties of the Ti64 are presented in Appendix 2. The as-received tensile specimens are not the standard specimens for testing. As shown in Attachment, Figure 1, only the 6 mm length is used in the reduced gage section of the specimens. As a result, a small change in the gage length will translate to a higher percentage change in elongation, giving higher elongation values than using the 30 mm length of the specimen. Since most of the deformation is concentrated in the reduced gage section, the present results are more accurate measurement of ductility. The Ti64 specimens failed in the center of the gage section. The Ti64 alloy contains extra low interstitials (ELI). There are an advantage and a disadvantage to having ELI. The advantage is that the alloy can exhibit good ductility since there is no effective deformation hindrance to mitigate the deformation twinning. The strength of the alloy is predominantly obtained from fine, equiaxed a grains. Given only the SHT, the alloy exhibits an adequate strength and ductility combination. The disadvantage of ELI is that the Young's modulus is sensitive to composition and heat treatment. The present alloy displays slightly lower Young's modulus values than the reported value of 108 GPa with the comparable SHT [1]. If needed, higher Young's modulus and strength can be obtained with subsequent aging treatment. The fracture surfaces of the specimens suggest ductile, dimple failure. Figure 3 shows the representative fracture characteristics of SHT Ti64. The cross-sectional view of the broken specimen has the appearance of extensive deformation prior to fracture (see Fig. 3a). The contribution of microstructure is clearly seen in the fracture surface, where the larger dimples represent the {alpha} phase since the dimple sizes are equivalent to the grain size. The smaller dimples are surmised to be {beta} precipitates. In addition to dimples, the fracture surface contained some sheared grains, indicated by the arrow in Figure 3b. It is inferred that since the deformation mechanism is twinning, it could be the twin interface separation.

  10. Mon. Not. R. Astron. Soc. 370, 19912003 (2006) doi:10.1111/j.1365-2966.2006.10624.x [Ti II] and [Ni II] emission from the strontium filament of Carinae

    E-Print Network [OSTI]

    2006-01-01

    ] and [Ni II] emission from the strontium filament of Carinae M. A. Bautista,1 H. Hartman,2 T. R. Gull,3 N filament found in the ejecta of Carinae. To this purpose, we employ multilevel models of the Ti II and Ni II systems, which are used to investigate the physical condition of the filament and the excitation

  11. Effect of Ti-Al cathode composition on plasma generation and plasma transport in direct current vacuum arc

    SciTech Connect (OSTI)

    Zhirkov, I. Petruhins, A.; Dahlqvist, M.; Ingason, A. S.; Rosen, J.; Eriksson, A. O.

    2014-03-28

    DC arc plasma from Ti, Al, and Ti{sub 1-x}Al{sub x} (x?=?0.16, 0.25, 0.50, and 0.70) compound cathodes was characterized with respect to plasma chemistry and charge-state-resolved ion energy. Scanning electron microscopy, X-ray diffraction, and Energy-dispersive X-ray spectroscopy of the deposited films and the cathode surfaces were used for exploring the correlation between cathode-, plasma-, and film composition. Experimental work was performed at a base pressure of 10{sup ?6}?Torr, to exclude plasma-gas interaction. The plasma ion composition showed a reduction of Al of approximately 5 at. % compared to the cathode composition, while deposited films were in accordance with the cathode stoichiometry. This may be explained by presence of neutrals in the plasma/vapour phase. The average ion charge states (Ti?=?2.2, Al?=?1.65) were consistent with reference data for elemental cathodes, and approximately independent on the cathode composition. On the contrary, the width of the ion energy distributions (IEDs) were drastically reduced when comparing the elemental Ti and Al cathodes with Ti{sub 0.5}Al{sub 0.5}, going from??150 and ?175?eV to ?100 and ?75?eV for Ti and Al ions, respectively. This may be explained by a reduction in electron temperature, commonly associated with the high energy tail of the IED. The average Ti and Al ion energies ranged between ?50 and ?61?eV, and ?30 and ?50?eV, respectively, for different cathode compositions. The attained energy trends were explained by the velocity rule for compound cathodes, which states that the most likely velocities of ions of different mass are equal. Hence, compared to elemental cathodes, the faster Al ions will be decelerated, and the slower Ti ions will be accelerated when originating from compound cathodes. The intensity of the macroparticle generation and thickness of the deposited films were also found to be dependent on the cathode composition. The presented results may be of importance for choice of cathodes for thin film depositions involving compound cathodes.

  12. Tribological Characteristics of Single-phase AlMgB14 and Nanocomposite AlMgB14-TiB2 Superhard Coatings

    SciTech Connect (OSTI)

    Qu, Jun; Blau, Peter Julian; Zhu, Dong; Cook, Bruce A; Elmoursi, Alaa A

    2008-01-01

    This study investigated the friction and wear characteristics of AlMgB14 and AlMgB14-TiB2 superhard coatings, produced by pulse laser deposition (PLD) and physical vapor deposition (PVD), respectively. Tests were conducted under unidirectional and reciprocating sliding against AISI 52100 bearing steel in both dry and oil-lubricated conditions. The AlMgB14 coating exhibited an encouraging but short-lived low friction stage (u = 0.2) in dry sliding. The AlMgB14-TiB2 coating reduced the wear rates by one order of magnitude for itself and three orders of magnitude for the counterface compared with the uncoated M2 tool steel in dry sliding. This nanocomposite coating also demonstrated significant extension (>2.5X) of the low friction (non-scuffing) stage in a lubricant starvation sliding.

  13. Microstructure characterization of laser welded Ti-6Al-4V fusion zones

    SciTech Connect (OSTI)

    Xu, Pei-quan; Li, Leijun, E-mail: leijun.li@ualberta.ca; Zhang, Chunbo

    2014-01-15

    The as-welded microstructure of laser-welded Ti-6Al-4V is characterized as a function of CO2 key-hole mode laser welding speed. Martensitic ?? is the predominant phase, with some ? and retained ?. Phase transformation is affected by the cooling rate through laser welding speed. A higher welding speed of 1.6 to 2.0 m/min produced more martensite ?? and less retained ? in the welds. 1.4 m/min welding speed produced small amounts of ?, besides the martensite ??. A trace of ? titanium hydride phase seems to have formed in the weld fusion zone. Moiré fringes are a common feature in the TEM microstructure, due to abundance of multi-phase interfaces. Tensile twins and clusters of dislocations indicate that plastic deformation has happened in the as-welded microstructure, indicating the local stress levels to be approaching the yield stress on-cooling during laser welding.

  14. PHYSICAL REVIEW B 88, 035405 (2013) Influence of atomic termination on the LaAlO3/SrTiO3 interfacial polar rearrangement

    E-Print Network [OSTI]

    Marrucci, Lorenzo

    2013-01-01

    PHYSICAL REVIEW B 88, 035405 (2013) Influence of atomic termination on the LaAlO3/SrTiO3 spectroscopy of LaAlO3 films grown on SrTiO3 (001) substrates having either TiO2 or SrO atomic terminations. The atomic termination is found to have a large effect on the observed spectra, with a strong dependence

  15. Mixed-Mode, High-Cycle Fatigue-Crack Growth Thresholds in Ti-6Al-4V

    E-Print Network [OSTI]

    Ritchie, Robert

    and control of failure due to high cycle fatigue (HCF) in turbine engine components is currently one and Engineering University of California, Berkeley, CA 94720-1760 ABSTRACT: There are few experimental results-cycle fatigue-crack growth thresholds with crack size and shape are reported for a Ti-6Al-4V turbine blade alloy

  16. Short and Large Crack, Mixed-Mode Fatigue-Crack Growth Thresholds in Ti-6Al-4V1

    E-Print Network [OSTI]

    Ritchie, Robert

    and control of failures due to high cycle fatigue (HCF) in turbine engine components is currently one, Dr. J. P. Campbell and Professor R. O. Ritchie2 Department of Materials Science and Engineering-crack growth thresholds with crack size and shape are reported for a Ti-6Al-4V turbine blade alloy, heat

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

    SciTech Connect (OSTI)

    Tuilier, M.-H.; Pac, M.-J.; Girleanu, M.; Covarel, G.; Arnold, G.; Louis, P.; Rousselot, C.; Flank, A.-M.

    2008-04-15

    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.

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

    E-Print Network [OSTI]

    Thawabi, Hassan S

    2013-04-16

    . 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...

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

    SciTech Connect (OSTI)

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

    2012-08-01

    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.

  20. Deformation and fracture behavior of Ni-Mo-Al (. gamma. /. gamma. -. cap alpha. ) in-situ composite

    SciTech Connect (OSTI)

    Siramamurthy, A.M.; Tewari, S.N.

    1984-10-01

    Tensile properties for directionally solidified (DS) eutectic alloy of a nominal composition Ni-33 Mo-5.7 Al (weight percent) have been investigated at room and elevated temperatures. The microstructure-mechanical property relationship has been studied for the as-DS and heat-treated conditions. Changes in yield strength, work hardening behavior, and fracture morphology are explained in terms of microstructural changes due to heat treatment. The yield drops are attributed to microdebonding due to segregation of impurities at the fiber-matrix interface and partly to strain aging.

  1. High-temperature phase transformation in Cr added TiAl base alloy

    SciTech Connect (OSTI)

    Abe, E.; Niinobe, K.; Nobuki, M.; Nakamura, M.; Tsujimoto, T.

    1999-07-01

    The authors have investigated a microstructure evolution of a Ti-48Al-3.5Cr (in at.%) alloy at high-temperatures ({gt} 1,473K). In the alloy annealed at 1673K for 1.8ks, followed by air-cooling, a characteristic microstructure with a feathery fashion was uniformly formed. From a cooling-rate-controlling study, it was found that formation of the feathery structure is accomplished during continuous cooling from 1673K to 1573K, within the {alpha} + {gamma} two-phase region. Transmission electron microscopy revealed that the feathery structure is composed of lamellar colonies (5--10{micro}m) which are crystallographically tilted slightly (a few degree) with their neighbors. A surprising fact is that lamellae in each colony are mostly the {gamma} phase with few {alpha}{sub 2} phase less than 5% in volume. This suggests that the feathery structure is a metastable product and has not resulted from the {alpha} {r{underscore}arrow} {alpha} + {gamma} transformation above 1,573 K. Instead, the feathery structure formation should be attributed to the non-equilibrium {alpha} {r{underscore}arrow} {gamma} transformation which occurs at high-temperatures with a small degree of supercooling. The authors discuss this interesting phase transformation in terms of the {alpha} {r{underscore}arrow} {gamma} massive transformation, based on the continuous-cooling-transformation (CCT) diagram constructed for the present alloy.

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

    E-Print Network [OSTI]

    Sparks, Donald L.

    , industrial waste disposal, atmospheric deposition, and application of fertilizers and pesticides (1 and Soil Sciences, University of Delaware, 147 Townsend Hall, Newark, Delaware 19717-1303, and Waste Management Laboratory, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland The kinetics of mixed Ni

  3. Direct Measurement of the Nanoscale Mechanical Properties of NiTi Shape Memory Gordon A. Shaw1

    E-Print Network [OSTI]

    Crone, Wendy C.

    .035 µm with Nitinol (roughly 49.5 atomic % Ni). Subsequent to annealing, the 10 and 1.7 µm films were

  4. Equivalence of optical and electrical noise equivalent power of hybrid NbTiN-Al microwave kinetic inductance detectors

    SciTech Connect (OSTI)

    Janssen, R. M. J.; Endo, A.; Visser, P. J. de; Klapwijk, T. M.; Baselmans, J. J. A.

    2014-11-10

    We have measured and compared the response of hybrid NbTiN-Al Microwave Kinetic Inductance Detectors (MKIDs) to changes in bath temperature and illumination by sub-mm radiation. We show that these two stimulants have an equivalent effect on the resonance feature of hybrid MKIDs. We determine an electrical noise equivalent power (NEP) from the measured temperature responsivity, quasiparticle recombination time, superconducting transition temperature, and noise spectrum, all of which can be measured in a dark environment. For the two hybrid NbTiN-Al MKIDs studied in detail, the electrical NEP is within a factor of two of the optical NEP, which is measured directly using a blackbody source.

  5. Recyclability study on Inconel 718 and Ti-6Al-4V powders for use in electron beam melting

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

    Nandwana, Peeyush; Peter, William H.; Lowe, Larry E.; Dehoff, Ryan R.; Medina, Francisco; Babu, Sudarsanam Suresh; Kirka, Michael M.

    2015-10-20

    In this study, powder bed based additive manufacturing technologies offer a big advantage in terms of reusability of the powders over multiple cycles that result in cost savings. However, currently there are no standards to determine the factors that govern the powder reuse times. This work presents the results from a recyclability study conducted on Inconel 718 and Ti-6Al-4V powders. It has been found that the Inconel 718 powders are chemically stable over a large number of cycles and their reuse time is limited by physical characteristics of powders such as flowability. Ti-6Al-4V, on the other hand, finds its reusemore »time governed by the oxygen pick up that occurs during and in between build cycles. The detailed results have been presented.« less

  6. Production of 26Al, 44Ti and 60Fe in Supernovae-sensitivity to the helium burning rates

    E-Print Network [OSTI]

    Clarisse Tur; Alexander Heger; Sam M. Austin

    2010-12-21

    We have studied the sensitivity of supernova production of the gamma emitting nuclei 26Al, 44Ti and 60Fe to variations of the rates of the triple alpha and 12C(alpha, gamma) reactions. Over a range of twice their experimental uncertainties we find variations in the production of 60Fe by more than a factor of five. Smaller variations, about a factor of two to three, were observed for 26Al and 44Ti. The yields of these isotopes change significantly when the abundances of Lodders (2003) are used instead of those of Anders and Grevesse (1989). These sensitivities will limit conclusions based on a comparison of observed gamma ray intensities and stellar models until the helium burning rates are better known. Prospects for improving the helium burning rates are discussed and a new version of the Boyes rate for 12C(alpha, gamma} is presented.

  7. Directly correlated transmission electron microscopy and atom probe tomography of grain boundary oxidation in a Ni-Al binary alloy exposed to high-temperature water.

    SciTech Connect (OSTI)

    Schreiber, Daniel K.; Olszta, Matthew J.; Bruemmer, Stephen M.

    2013-10-30

    Intergranular oxidation of a Ni-4Al alloy exposed to hydrogenated, high-temperature water was characterized using directly correlated transmission electron microscopy and atom probe tomography. These combined analyses revealed that discrete, well-separated oxides (NiAl2O4) precipitated along grain boundaries in the metal. Aluminum was depleted from the grain boundary between oxides and also from one side of the boundary as a result of grain boundary migration. The discrete oxide morphology, disconnected from the continuous surface oxidation, suggests intergranular solid-state internal oxidation of Al. Keywords: oxidation; grain boundaries; nickel alloys; atom probe tomography; transmission electron microscopy (TEM)

  8. Electronic Charges and Electric Potential at LaAlO3/SrTiO3 Interfaces Studied by Core-Level Photoemission Spectroscopy

    SciTech Connect (OSTI)

    Hwang, Harold

    2011-08-19

    We studied LaAlO{sub 3}/SrTiO{sub 3} interfaces for varying LaAlO{sub 3} thickness by core-level photoemission spectroscopy. In Ti 2p spectra for conducting 'n-type' interfaces, Ti{sup 3+} signals appeared, which were absent for insulating 'p-type' interfaces. The Ti{sup 3+} signals increased with LaAlO{sub 3} thickness, but started well below the critical thickness of 4 unit cells for metallic transport. Core-level shifts with LaAlO{sub 3} thickness were much smaller than predicted by the polar catastrophe model. We attribute these observations to surface defects/adsorbates providing charges to the interface even below the critical thickness.

  9. Catalytic Nonoxidation Dehydrogenation of Ethane Over Fe-Ni Catalysts Supported on Mg (Al)O to Produce Hydrogen and Easily Purified Carbon Nanotubes

    SciTech Connect (OSTI)

    Shen,W.; Wang, Y.; Shi, X.; Shah, N.; Huggins, F.; Bollineni, S.; Seehra, M.; Huffman, G.

    2007-01-01

    Nonoxidative decomposition of ethane was conducted over monometallic Ni and bimetallic Fe-Ni catalysts on basic Mg(Al)O support to produce H2 free of CO and CO2 and easily purified carbon nanotubes, a potentially valuable byproduct. The Mg(Al)O support was prepared by calcination of synthetic MgAl-hydrotalcite with a Mg to Al ratio of 5. The catalysts were prepared by incipient wetness with total metal loadings of 5 wt %. The dehydrogenation of undiluted ethane was conducted at temperatures of 500, 650, and 700 C. At 500 C, the Ni/Mg(Al)O catalyst was highly active and very stable with 100% conversion of ethane to 20 vol % H2 and 80 vol % CH4. However, the bimetallic Fe-Ni/Mg(Al)O exhibited its best performance at 650 C, yielding 65 vol % H2, 10 vol % CH4, and 25 vol % unreacted ethane. The product carbon was in the form of carbon nanotubes (CNT) at all three reaction temperatures, but the morphology of the CNT depended on both the catalyst composition and reaction temperature. The CNTs were formed by a tip-growth mechanism over the Mg(Al)O supported catalysts and were easily purified by a one-step dilute nitric acid treatment. Mossbauer spectroscopy, X-ray absorption fine structure spectroscopy, N2 adsorption-desorption isotherms, TEM, STEM, TGA, and XRD were used to characterize the catalysts and the CNT, revealing the catalytic mechanisms.

  10. Stoichiometry dependence of potential screening at La ( 1 - ? ) Al ( 1 + ? ) O 3 / SrTiO 3 interfaces

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

    Weiland, Conan; Sterbinsky, George E.; Rumaiz, Abdul K.; Hellberg, C. Stephen; Woicik, Joseph C.; Zhu, Shaobo; Schlom, Darrell G.

    2015-04-03

    Hard x-ray photoelectron spectroscopy (HAXPES) and variable kinetic energy x-ray photoelectron spectroscopy (VKE-XPS) analyses have been performed on ten-unit-cell-thick La(1-?)Al(1+?)O? films, with La:Al ratios of 1.1, 1.0, and 0.9, deposited on SrTiO?. Only Al-rich films are known to have a conductive interface. VKE-XPS, coupled with maximum entropy analysis, shows significant differences in the compositional depth profile among the Al-rich, La-rich, and stoichiometric films: significant La enrichment at the interface is observed in the La-rich and stoichiometric films, while the Al-rich film shows little to no intermixing. Additionally, the La-rich and stoichiometric films show a high concentration of Al at themore »surface, which is not observed in the Al-rich film. HAXPES valence band (VB) analysis shows a broadening of the VB for the Al-rich sample relative to the stoichiometric and La-rich samples. This broadening is consistent with an electric field across the Al-rich film. These results are consistent with a defect-driven electronic reconstruction.« less

  11. Stoichiometry dependence of potential screening at La ( 1 - ? ) Al ( 1 + ? ) O 3 / SrTiO 3 interfaces

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

    Weiland, Conan; Sterbinsky, George E.; Rumaiz, Abdul K.; Hellberg, C. Stephen; Woicik, Joseph C.; Zhu, Shaobo; Schlom, Darrell G.

    2015-04-01

    Hard x-ray photoelectron spectroscopy (HAXPES) and variable kinetic energy x-ray photoelectron spectroscopy (VKE-XPS) analyses have been performed on ten-unit-cell-thick La(1-?)Al(1+?)O? films, with La:Al ratios of 1.1, 1.0, and 0.9, deposited on SrTiO?. Only Al-rich films are known to have a conductive interface. VKE-XPS, coupled with maximum entropy analysis, shows significant differences in the compositional depth profile among the Al-rich, La-rich, and stoichiometric films: significant La enrichment at the interface is observed in the La-rich and stoichiometric films, while the Al-rich film shows little to no intermixing. Additionally, the La-rich and stoichiometric films show a high concentration of Al at the surface, which is not observed in the Al-rich film. HAXPES valence band (VB) analysis shows a broadening of the VB for the Al-rich sample relative to the stoichiometric and La-rich samples. This broadening is consistent with an electric field across the Al-rich film. These results are consistent with a defect-driven electronic reconstruction.

  12. Microstructure and oxidation behavior of NiCoCrAl/YSZ microlaminates produced by EB-PVD

    SciTech Connect (OSTI)

    Shi Guodong, E-mail: gdshi@dlut.edu.cn [State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian 116024 (China); Wang Zhi; Liu Mincong [State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian 116024 (China); Liang Jun [Center for Composite Materials, Harbin Institute of Technology, Harbin, 150001 (China); Wu Zhanjun [State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian 116024 (China)

    2011-11-15

    Two NiCoCrAl/ZrO{sub 2}-Y{sub 2}O{sub 3} microlaminates (A and B) were fabricated by electron beam physical vapor deposition, which were different in layer number and metal-layer thickness. The layer number was 20 and 26, respectively. And the metal-layer thickness was 35 and 14 {mu}m, respectively. The microstructure and isothermal oxidation behavior were investigated. During the exposure in air at 1000 deg. C for 100 h, the t to m phase transformation occurred in the ceramic layers, and oxide scales formed at the surfaces of not only the outer metal-layers but also the internal metal-layers for the microlaminates. The oxidation rate of microlaminate B was greater than that of microlaminate A. Their overall mass gains were significantly dependent on the number and thickness of the metal-layers. The oxidation products were also influenced by metal-layer thickness. Oxide scales of the 35 {mu}m thick metal-layer microlaminate (A) consisted mainly of {alpha}-Al{sub 2}O{sub 3} and {theta}-Al{sub 2}O{sub 3}, while the oxidation products of the 14 {mu}m thick metal-layer microlaminate (B) were the mixture of {alpha}-Al{sub 2}O{sub 3}, {theta}-Al{sub 2}O{sub 3} and Cr{sub 2}O{sub 3}. It was also found that the growth of the oxide scale adjacent to the top YSZ layer was controlled by the oxygen diffusion, and that the growth of the oxide scale adjacent to the internal YSZ layer was controlled by the metal ionic diffusion. - Highlights: {yields} Effect of laminate structure on oxidation behavior of microlaminates was studied. {yields} Oxygen diffusion through YSZ layers led to the oxidation of internal metal-layers. {yields} The thinner NiCoCrAl layer was more difficult to form the stable Al{sub 2}O{sub 3} scale. {yields} Control of oxide scale growth by the oxygen diffusion in the outer metal-layers. {yields} Control of oxide scale growth by the metal ionic diffusion in internal metal-layers.

  13. An investigation on microstructure evolution and mechanical properties during liquid state diffusion bonding of Al2024 to Ti–6Al–4V

    SciTech Connect (OSTI)

    Samavatian, Majid; Halvaee, Ayoub; Amadeh, Ahmad Ali; Khodabandeh, Alireza

    2014-12-15

    Joining mechanism of Ti/Al dissimilar alloys was studied during liquid state diffusion bonding process using Cu/Sn/Cu interlayer at 510 °C under vacuum of 7.5 × 10{sup ?5} Torr for various bonding times. The microstructure and compositional changes in the joint zone were analyzed by scanning electron microscopy equipped with energy dispersive spectroscopy and X-ray diffraction. Microhardness and shear strength tests were also applied to study the mechanical properties of the joints. It was found that with an increase in bonding time, the elements of interlayer diffused into the parent metals and formed various intermetallic compounds at the interface. Diffusion process led to the isothermal solidification and the bonding evolution in the joint zone. The results from mechanical tests showed that microhardness and shear strength values have a straight relation with bonding time so that the maximum shear strength of joint was obtained for a bond made with 60 min bonding time. - Highlights: • Liquid state diffusion bonding of Al2024 to Ti–6Al–4V was performed successfully. • Diffusion of the elements caused the formation of various intermetallics at the interface. • Microhardness and shear strength values have a straight relation with bonding time. • The maximum shear strength reached to 36 MPa in 60 min bonding time.

  14. Influence of interfacial reactions on the fiber-matrix interfacial shear strength in sapphire fiber-reinforced NiAl(Yb) composites

    SciTech Connect (OSTI)

    Tewari, S.N.; Smith, J. . Dept. of Chemical Engineering); Asthana, R.; Bowman, R.R. . Materials Division); Tiwari, R. )

    1995-02-01

    The influence of microstructure of the fiber-matrix interface on the interfacial shear strength, measured using a fiber-pushout technique, has been examined in a sapphire-fiber-reinforced NiAl(Yb) matrix composite under the following conditions: (1) as-fabricated powder metallurgy (PM) composites, (2) PM composites after solid-state heat treatment (HT), and (3) PM composites after directional solidification (DS). The fiber-pushout stress-displacement behavior consisted of an initial pseudoelastic'' region, wherein the stress increased linearly with displacement, followed by an inelastic'' region, where the slope of the stress-displacement plot decrease until a maximum stress was reached, and the subsequent gradual stress decreased to a frictional'' stress. Energy-dispersive spectroscopy (EDS) and X-ray analyses showed that the interfacial region in the PM NiAl(Yb) composites was comprised of Yb[sub 2]O[sub 3], O-rich NiAl and some spinel oxide (Yb[sub 3]Al[sub 5]O[sub 12]), whereas the interfacial region in the HT and DS composites was comprised mainly of Yb[sub 3]Al[sub 5]O[sub 12]. A reaction mechanism has been proposed to explain the presence of interfacial species observed in the sapphire-NiAl(Yb) composite. The extent of interfacial chemical reactions and severity of fiber surface degradation increased progressively in this order: PM < HT < DS.

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

    SciTech Connect (OSTI)

    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)

    2011-01-01

    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.

  16. Surface characterization and immersion tests of TiNi alloy coated with Ta Y. Cheng*, W. Cai, Y.F. Zheng, H.T. Li, L.C. Zhao

    E-Print Network [OSTI]

    Zheng, Yufeng

    Surface characterization and immersion tests of TiNi alloy coated with Ta Y. Cheng*, W. Cai, Y shape memory effect, superelasticity as well as excellent biocom- patibility [1­4]. With the miniature the stricture vessel by shape memory effect or supereclasticity. The improvement of the radiopacity of stents

  17. Understanding the Nucleation and Growth of Metals on TiO2: Co Compared to Au, Ni, and Pt

    E-Print Network [OSTI]

    Henkelman, Graeme

    The Co-TiO2 system has also been used for other industrially relevant catalytic processes, including the steam reforming of ethanol,24 preferential oxidation of CO in hydrogen,25 and oxidative dehydrogenation

  18. Converse magnetoelectric coupling in NiFe/Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}–PbTiO{sub 3} nanocomposite thin films grown on Si substrates

    SciTech Connect (OSTI)

    Feng, Ming; Key Laboratory of Functional Materials Physics and Chemistry of the Ministry of Education, Jilin Normal University, Siping 136000 ; Hu, Jiamian; Wang, Jianjun; Li, Zheng; Shu, Li; Nan, C. W.

    2013-11-04

    Multiferroic NiFe (?30 nm)/Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}–PbTiO{sub 3}(PMN–PT, ?220 nm) bilayered thin films were grown on common Pt/Ti/SiO{sub 2}/Si substrates by a combination of off-axis magnetron sputtering and sol-gel spin-coating technique. By using AC-mode magneto-optical Kerr effect technique, the change in the Kerr signal (magnetization) of the NiFe upon applying a low-frequency AC voltage to the PMN–PT film was in situ acquired at zero magnetic field. The obtained Kerr signal versus voltage loop essentially tracks the electromechanical strain curve of the PMN–PT thin film, clearly demonstrating a strain-mediated converse magnetoelectric coupling, i.e., voltage-modulated magnetization, in the NiFe/PMN–PT nanocomposite thin films.

  19. Structure and magnetic properties of Ce?(Ni/Al/Ga)??-A...

    Office of Scientific and Technical Information (OSTI)

    Z 2) with a 436.38(14), b 1004.5(3) and c 1293.4(4) pm. This is a standardized unit cell of the previously published LaAl structure type. Wavelength dispersive...

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

    E-Print Network [OSTI]

    Harmouche, Mahmoud Redwan

    1984-01-01

    element alloying addition, and high potential for plastic flow at high temperatures. In addition, they have remarkable mechanical properties [2] . The melting temperature for the CoA1 and NiA1 systems is about 1900 K while that of the FeA1 is about..., measurements are a lot more time consum- ing. This is usually the case in physical and mechanical property . measurements but the actual time required to run a test (after preparation) is less than one hour. The validity of the measured Young's moduli using...

  1. Mechanisms of structural evolutions associated with the high current pulsed electron beam treatment of a NiTi shape memory alloy

    SciTech Connect (OSTI)

    Zhang, K. M.; Zou, J. X.; Grosdidier, T.; Gey, N.; Weber, S.; Yang, D. Z.; Dong, C. [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China) and State Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Dalian University of Technology, Dalian 116024 (China); School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); State Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Dalian University of Technology, Dalian 116024 (China); and Laboratoire d'Etude des Textures et Applications aux Materiaux (LETAM, UMR-CNRS 7078), Universite Paul Verlaine de Metz, Ile du Saulcy, 57012 Metz (France); Laboratoire d'Etude des Textures et Applications aux Materiaux (LETAM, UMR-CNRS 7078), Universite Paul Verlaine de Metz, Ile du Saulcy, 57012 Metz (France); Laboratoire de Physique des Materiaux (LPM, UMR-CNRS 7556), Ecole des Mines, Parc de Saurupt, 54042 Nancy (France); School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China) and State Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Dalian University of Technology, Dalian 116024 (China)

    2007-01-15

    The aim of this study was to investigate, for the first time, the surface modifications associated with the use the recently developed high current pulsed electron beam technique for modifying the surface of an intermetallic NiTi alloy. Samples were treated with the same electron beam parameters but different numbers of pulses (i.e., five and ten pulses) and the present article concentrates on a detailed characterization of their texture and microstructure modifications. The observation of surface features such as craters, wavy surfaces with protrusions, chemistry modifications, and the development of specific texture components are discussed as the consequence of the combination of surface melting and evaporation mechanisms. It is also shown that in the subsurface, below the melted layer, the martensitic transformation was triggered due to the effects of the thermal stresses and shock waves propagating in the material.

  2. Bull. Mater. Sci., Vol. 37, No. 4, June 2014, pp. 837842. Indian Academy of Sciences. CO impurities effect on LaNi47Al03 hydrogen storage alloy

    E-Print Network [OSTI]

    Volinsky, Alex A.

    impurities effect on LaNi47Al03 hydrogen storage alloy hydrogenation/dehydrogenation properties QI WAN1 and differential thermal analyses (TG + DTA). The hydrogen storage prop- erties were studied by the pressure in hydrogen containing 300 ppm CO at 30 °C, but hydrogen storage capacity did not degrade when tested at 80 °C

  3. Effect of Water Vapor on the 1100oC Oxidation Behavior of Plasma-Sprayed TBCs with HVOF NiCoCrAlX Bond Coatings

    SciTech Connect (OSTI)

    Haynes, James A; Unocic, Kinga A; Pint, Bruce A

    2013-01-01

    With the goal of investigating the reported detrimental effect of water vapor on thermal barrier coating (TBC) performance, furnace cycle experiments were conducted in dry O2 and air with 10 and 50% water vapor at 1100 C. The TBC systems evaluated were air plasma-sprayed (APS), yttria-stabilized zirconia (YSZ) top coatings with high velocity oxy fuel (HVOF)-deposited NiCoCrAlY or NiCoCrAlYHfSi bond coating. Average TBC lifetime was reduced by ~30% in air with 10% water vapor compared to cycling in dry O2, using 1h cycle durations. Superalloy substrates with Y and La additions also were investigated but showed no statistical change in the average TBC lifetime compared to the base CMSX4 superalloy. In all cases, the bond coating with Hf and Si additions increased YSZ lifetime by 20% or more. Experiments that increased water vapor to 50% showed no further decrease in TBC lifetime. Increasing the cycle frequency to 100h resulted in a large increase in TBC lifetime, especially for the NiCoCrAlYHfSi bond coatings. Co-doping the NiCoCrAl bond coat with Y and Hf was beneficial to TBC lifetime, but did not mitigate the detrimental impact of water vapor.

  4. Perpendicular local magnetization under voltage control in Ni films on ferroelectric BaTiO3 substrates

    E-Print Network [OSTI]

    Ghidini, Massimo; Maccherozzi, Francesco; Moya, Xavier; Phillips, Lee C.; Yan, Wenjing; Soussi, Jordane; Métallier, Nicolas; Vickers, Mary E.; Steinke, Nina -J.; Mansell, Rhodri; Barnes, Crispin H. W.; Dhesi, Sarnjeet S.; Mathur, Neil D.

    2015-01-12

    University of Cambridge Cambridge, CB3 0HE , UK Dr. N.-J. Steinke ISIS, Harwell Science and Innovation Campus Didcot , Oxfordshire, OX11 0QX , UK DOI: 10.1002/adma.201404799 and destroy an OOP anisotropy in large contiguous areas of Ni fi lms...

  5. The characterization of fluorocarbon films on NiTi alloy by magnetron sputtering *, F.T. Zi a

    E-Print Network [OSTI]

    Zheng, Yufeng

    reported. In our study, we used PTFE as the target, while the fluorocarbon films were prepared on Ni ultrasonically in acetone, methanol for 30 min, respec- tively, prior to being held on the cathode. A PTFE target between the substrates and the PTFE target was 85 mm and base pressure was 6.0 Â 10À4 Pa. The structure

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

    SciTech Connect (OSTI)

    Fister, T. T.; Hruszkewycz, S. O.; Proffit, D. L.; Eastman, J. A.; Fuoss, P. H.; Baldo, P. M.; Fong, D. D.; Zhou, H.; Luo, Z.; Seo, S. S. A.; Lee, H. N.

    2014-02-01

    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.

  7. 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]

    Ritchie, IAltenberger, RKNalla, YSano LWagner, RO

    2013-01-01

    high-cycle fatigue in a turbine engine Ti–6Al–4V alloy. Int.surface treatment in the turbine engine industry, although

  8. Lattice distortions and octahedral rotations in epitaxially strained LaNiO{sub 3}/LaAlO{sub 3} superlattices

    SciTech Connect (OSTI)

    Kinyanjui, M. K. E-mail: benckise@fkf.mpg.de; Kaiser, U.; Lu, Y.; Wu, M.; Wochner, P.; Christiani, G.; Logvenov, G.; Habermeier, H.-U.; Keimer, B.; Benckiser, E. E-mail: benckise@fkf.mpg.de; Gauquelin, N.; Botton, G. A.; Frano, A.; Reehuis, M.

    2014-06-02

    Using a complementary combination of x-ray diffraction and atomically resolved imaging we investigated the lattice structure of epitaxial LaNiO{sub 3}/LaAlO{sub 3} superlattices grown on a compressive-strain inducing LaSrAlO{sub 4} (001) substrate. A refinement of the structure obtained from the x-ray data revealed the monoclinic I 2/c 1 1 space group. The (Ni/Al)O{sub 6} octahedral rotation angle perpendicular to the superlattice plane is enhanced, and the one parallel to the plane is reduced with respect to the corresponding bulk values. High-angle annular dark field imaging was used to determine the lattice parameters within the superlattice unit cell. High-resolution electron microscopy images of the oxygen atoms are consistent with the x-ray results.

  9. Tunable bilayer two-dimensional electron gas in LaAlO{sub 3}/SrTiO{sub 3} superlattices

    SciTech Connect (OSTI)

    Ma, H. J. Harsan E-mail: phyarian@nus.edu.sg; Annadi, A.; Zeng, S. W.; Ariando E-mail: phyarian@nus.edu.sg; Huang, Z.; Lü, W. M.; Wong, L. M.; Wang, S. J.; Venkatesan, T.

    2014-07-07

    We report magnetotransport properties of double heterointerfaces in LaAlO{sub 3}/SrTiO{sub 3}/LaAlO{sub 3}/SrTiO{sub 3}(001) (LAO/STO/LAO/STO). A strong nonlinearity in the Hall resistivity is found when the temperature is below 80?K. This effect is attributed to multichannel conduction of interfacial charges generated in double heterostructures of LAO/STO where two-dimensional electron gas (2DEG) is produced. The multichannel conduction is confirmed by back gating modulation of Hall effect. Our result suggests the possibility to achieve coupled bilayer 2DEG layers in LAO/STO superlattices.

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

    SciTech Connect (OSTI)

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

    2013-12-01

    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.

  11. Built-in and Induced Polarization Across LaAlO3/SrTiO3 Heterojunctions

    SciTech Connect (OSTI)

    Guneeta, Singh-Bhalla

    2011-08-15

    Ionic crystals terminated at oppositely charged polar surfaces are inherently unstable and expected to undergo surface reconstructions to maintain electrostatic stability. Essentially, an electric field that arises between oppositely charged atomic planes gives rise to a built-in potential that diverges with thickness. Here we present evidence of such a built-in potential across polar LaAlO{sub 3} thin films grown on SrTiO{sub 3} substrates, a system well known for the electron gas that forms at the interface. By performing tunneling measurements between the electron gas and metallic electrodes on LaAlO{sub 3} we measure a built-in electric field across LaAlO{sub 3} of 80.1 meV/{angstrom}. Additionally, capacitance measurements reveal the presence of an induced dipole moment across the heterostructure. We forsee use of the ionic built-in potential as an additional tuning parameter in both existing and novel device architectures, especially as atomic control of oxide interfaces gains widespread momentum.

  12. High-cycle fatigue behavior of Ti-5Al-2.5Sn ELI alloy forging at low temperatures

    SciTech Connect (OSTI)

    Ono, Yoshinori; Yuri, Tetsumi; Ogata, Toshio; Demura, Masahiko; Matsuoka, Saburo; Sunakawa, Hideo

    2014-01-27

    High-cycle fatigue properties of Ti-5Al-2.5Sn Extra Low Interstitial (ELI) alloy forging were investigated at low temperatures. The high-cycle fatigue strength at low temperatures of this alloy was relatively low compared with that at ambient temperature. The crystallographic orientation of a facet formed at a fatigue crack initiation site was determined by electron backscatter diffraction (EBSD) method in scanning electron microscope (SEM) to understand the fatigue crack initiation mechanism and discuss on the low fatigue strength at low temperature. Furthermore, in terms of the practical use of this alloy, the effect of the stress ratio (or mean stress) on the high-cycle fatigue properties was evaluated using the modified Goodman diagram.

  13. Surface Quality of Ti-6%Al-4%V ELI When Machined Using CVD-Carbide Tools at High Cutting Speed

    SciTech Connect (OSTI)

    Gusri, A. I.; Che Hassan, C. H.; Jaharah, A. G.; Yasir, A.; Zaid, Y.; Yanuar, B.

    2011-01-17

    Machining of Ti-6Al-4V ELI becomes more interested topic due to extremely weight-to-strength ratio and resistance to corrosion at elevated temperature. Quality of machined surface is presented by surface roughness, surface texture and damages of microstructure of titanium alloys. The turning parameters evaluated are cutting speed of 55-95 m/min, feed rate of 0.15-0.35 mm/rev, depth of cut of 0.10-0.20 mm and tool grade of CVD carbide tools. The results show the trend lines of surface roughness value are higher at the initial machining and the surface texture profile has a strong correlation with the feed rate. At the machining condition of cutting speed of 95 m/min, feed rate of 0.35 mm/rev and depth of cut of 0.10 mm produced the with layer with thickness of 2.0 {mu}m.

  14. Structural Comparison of n-type and p-type LaAlO3/SrTiO3 Interfaces

    SciTech Connect (OSTI)

    Bell, Christopher

    2011-08-19

    Using a surface x-ray diffraction technique, we investigated the atomic structure of two types of interfaces between LaAlO{sub 3} and SrTiO{sub 3}, that is, p-type (SrO/AlO{sub 2}) and n-type (TiO{sub 2}/LaO) interfaces. Our results demonstrate that the SrTiO{sub 3} in the sample with the n-type interface has a large polarized region, while that with the p-type interface has a limited polarized region. In addition, the atomic intermixing was observed to extend deeper into STO substrate at the n-type interface than at the p-type. These differences result in different degrees of band bending, which likely contributes to the striking difference in electrical conductivity between the two types of interfaces.

  15. Microstructural evolution and characterisation of interfacial phases in Al2O3/Ag-Cu-Ti/Al2O3 braze joints

    E-Print Network [OSTI]

    Ali, M.; Knowles, K. M.; Mallinson, P. M.; Fernie, J. A.

    2015-06-14

    . With the 0.7 at% Ti alloy, wetting was controlled by a titanium oxide layer, resulting in a contact angle of 63°. With the 8.0 at% Ti alloy, a layer containing both Ti3Cu3O and Ti4Cu2O was observed, resulting in a similar contact angle to that obtained... inhomogeneous interfacial structures, with some regions of interface lacking evidence for preserving a chemical bond between the ABA and alumina. Other regions show significant development of the titanium oxide layer along with decomposition of the Ti3Cu3O...

  16. Effect of the overlapping factor on the microstructure and mechanical properties of pulsed Nd:YAG laser welded Ti6Al4V sheets

    SciTech Connect (OSTI)

    Gao, Xiao-Long; Liu, Jing; Zhang, Lin-Jie, E-mail: zhanglinjie@mail.xjtu.edu.cn; Zhang, Jian-Xun

    2014-07-01

    The effect of the overlapping factor on the microstructures and mechanical properties of pulsed Nd:YAG laser welded Ti6Al4V alloy sheets was investigated by microstructural observations, microhardness tests, tensile tests and fatigue tests. A microstructural examination shows that by increasing the overlapping factor, the grains in the fusion zone become coarser, and the width of the heat affected zone increases. As overlapping factor increases, the width of region composed completely of martensite ?? and the secondary ? phase in the heat affected zone increases, consequently the gradient of microstructure along the direction from the fusion zone to base metal decreases, so does the gradient of microhardness. The results of tensile and fatigue tests reveal that the joints made using medium overlapping factor exhibit better mechanical properties than those welded with low and high overlapping factors. Based on the experimental results, it can be stated that a sound weld of Ti6Al4V alloy can be obtained if an appropriate overlapping factor is used. - Highlights: • The weld quality of Ti6Al4V alloy under various overlapping factors was assessed. • Tensile and fatigue tests were conducted with as-welded specimen. • Localized strain across the weld was measured using DIC photogrammetry system. • A sound weld of Ti6Al4V alloy is obtained by using right overlapping factor.

  17. Effect of oxygen incorporation on the structure and elasticity of Ti-Al-O-N coatings synthesized by cathodic arc and high power pulsed magnetron sputtering

    SciTech Connect (OSTI)

    Hans, M. Baben, M. to; Music, D.; Ebenhöch, J.; Schneider, J. M.; Primetzhofer, D.; Kurapov, D.; Arndt, M.; Rudigier, H.

    2014-09-07

    Ti-Al-O-N coatings were synthesized by cathodic arc and high power pulsed magnetron sputtering. The chemical composition of the coatings was determined by means of elastic recoil detection analysis and energy dispersive X-ray spectroscopy. The effect of oxygen incorporation on the stress-free lattice parameters and Young's moduli of Ti-Al-O-N coatings was investigated by X-ray diffraction and nanoindentation, respectively. As nitrogen is substituted by oxygen, implications for the charge balance may be expected. A reduction in equilibrium volume with increasing O concentration is identified by X-ray diffraction and density functional theory calculations of Ti-Al-O-N supercells reveal the concomitant formation of metal vacancies. Hence, the oxygen incorporation-induced formation of metal vacancies enables charge balancing. Furthermore, nanoindentation experiments reveal a decrease in elastic modulus with increasing O concentration. Based on ab initio data, two causes can be identified for this: First, the metal vacancy-induced reduction in elasticity; and second, the formation of, compared to the corresponding metal nitride bonds, relatively weak Ti-O and Al-O bonds.

  18. Influence of Microstructure on Residual Thermal Stresses in TiCxN1-x and -Al2O3 Coatings on WC-Co Tool Inserts

    E-Print Network [OSTI]

    Rohrer, Gregory S.

    deposited coatings on four tool inserts have been comprehensively characterized using electron backscatter to enhance the performance, durability, and wear resistance of cemented carbide cutting tool insertsInfluence of Microstructure on Residual Thermal Stresses in TiCxN1-x and -Al2O3 Coatings on WC

  19. Experiments and finite element simulations on micro-milling of Ti6Al4V alloy with uncoated and cBN coated micro-tools

    E-Print Network [OSTI]

    Ozel, Tugrul

    BN coated micro-tools T. O¨ zel (2)a, *, T. Thepsonthi a , D. Ulutan a , B. Kaftanoglu (1)b a Manufacturing. In these micro-tools, sharp cutting edges cannot be fabricated due to the limited edge strength; hence often of titanium alloys [8] and particularly advantages of cubic boron nitrite (cBN) coatings in cutting of Ti­6Al

  20. Evaluation of the interfacial shear strength and residual stress of TiAlN coating on ZIRLOTM fuel cladding using a modified shear-lag model

    E-Print Network [OSTI]

    Motta, Arthur T.

    Evaluation of the interfacial shear strength and residual stress of TiAlN coating on ZIRLOTM fuel Accepted 2 June 2015 Available online xxx Keywords: ATF (accident tolerant fuel) coating Micromechanical modelling Metal-coating interface Fission Zirconium Accident tolerant fuels (ATF) a b s t r a c t This paper

  1. Interfacial reactions in epitaxial Al/TiN(111) model diffusion barriers: Formation of an impervious self-limited wurtzite-structure AIN(0001) blocking layer

    SciTech Connect (OSTI)

    Chun, J.-S.; Desjardins, P.; Lavoie, C.; Shin, C.-S.; Cabral, C.; Petrov, I.; Greene, J. E.

    2001-06-15

    Single-crystal TiN(111) layers, 45 nm thick, were grown on MgO(111) by ultrahigh vacuum reactive magnetron sputter deposition in pure N{sub 2} discharges at T{sub s}=700{degree}C. Epitaxial Al(111) overlayers, 160 nm thick, were then deposited at T{sub s}=100{degree}C in Ar without breaking vacuum. Interfacial reactions and changes in bilayer microstructure due to annealing at 620 and 650{degree}C were investigated using x-ray diffraction and transmission electron microscopy (TEM). The interfacial regions of samples annealed at 620{degree}C consist of continuous {approx_equal}7-nm-thick epitaxial wurtzite-structure AlN(0001) layers containing a high density of stacking faults, with {approx_equal}22 nm thick tetragonal Al{sub 3}Ti(112) overlayers. Surprisingly, samples annealed at the higher temperature are more stable against Al{sub 3}Ti formation. TEM analyses of bilayers annealed at 650{degree}C (10{degree}C below the Al melting point!) reveal only the self-limited growth of an {approx_equal}3-nm-thick interfacial layer of perfect smooth epitaxial wurtzite-structure AlN(0001) which serves as an extremely effective deterrent for preventing further interlayer reactions. {copyright} 2001 American Institute of Physics.

  2. Structural and magnetic properties of Co{sub 2}Ti{sub 1?x}Fe{sub x}Al (0 ? x ? 0.5) alloys

    SciTech Connect (OSTI)

    Pal, Lakhan Gupta, Sachin Suresh, K. G.

    2014-04-24

    In this work we studied the effect of partial Fe substitution for Ti on the structural and magnetic properties of the Co{sub 2}TiAl. X-ray diffraction analysis indicates the presence of B2 type disorder for x > 0, (111) reflections are absent for x > 0 which is the characteristic of B2 type disorder. XRD analysis also shows presence of second phase. Magnetization measurements also confirm the presence of dual phase. Curie temperature of the alloys increases with increase in Fe concentration. Saturation magnetic moments agree very well with those calculated by Slater-Pauling rule.

  3. Influence of oxygen pressure and aging on LaAlO{sub 3} films grown by pulsed laser deposition on SrTiO{sub 3} substrates

    SciTech Connect (OSTI)

    Park, Jihwey; Aeppli, Gabriel [London Centre for Nanotechnology, University College London, London WC1H 0AH (United Kingdom); Soh, Yeong-Ah, E-mail: yeongahsoh@gmail.com [London Centre for Nanotechnology, University College London, London WC1H 0AH (United Kingdom); Department of Materials, Imperial College London, London SW7 2AZ (United Kingdom); David, Adrian; Lin, Weinan [Division of Physics and Applied Physics, Nanyang Technological University, Singapore 637371 (Singapore); Wu, Tom [Physical Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900 (Saudi Arabia)

    2014-02-24

    The crystal structures of LaAlO{sub 3} films grown by pulsed laser deposition on SrTiO{sub 3} substrates at oxygen pressure of 10{sup ?3} millibars or 10{sup ?5} millibars, where kinetics of ablated species hardly depend on oxygen background pressure, are compared. Our results show that the interface between LaAlO{sub 3} and SrTiO{sub 3} is sharper when the oxygen pressure is lower. Over time, the formation of various crystalline phases is observed while the crystalline thickness of the LaAlO{sub 3} layer remains unchanged. X-ray scattering as well as atomic force microscopy measurements indicate three-dimensional growth of such phases, which appear to be fed from an amorphous capping layer present in as-grown samples.

  4. Growth and transport properties of epitaxial lattice matched half Heusler CoTiSb/InAlAs/InP(001) heterostructures

    SciTech Connect (OSTI)

    Kawasaki, Jason K.; Johansson, Linda I. M.; Schultz, Brian D.; Palmstrøm, Chris J.

    2014-01-13

    We demonstrate the integration of the lattice matched single crystal epitaxial Half Heusler compound CoTiSb with In{sub 0.52}Al{sub 0.48}As/InP(001) heterostructures using molecular beam epitaxy. CoTiSb belongs to the subset of Half Heusler compounds that is expected to be semiconducting, despite being composed entirely of metallic constituents. The lattice matching and epitaxial alignment of the CoTiSb films were confirmed by reflection high energy electron diffraction and X-ray diffraction. Temperature dependent transport measurements indicate semiconducting-like behavior, with a room temperature Hall mobility of 530 cm{sup 2}/Vs and background Hall carrier density of 9.0?×?10{sup 17}?cm{sup ?3}, which is comparable to n-Si with similar carrier density. Below 100?K, the films show a large negative magnetoresistance, and possible origins of this negative magnetoresistance are discussed.

  5. O3-type layered transition metal oxide Na(NiCoFeTi)1/4O2 as a high rate and long cycle life cathode material for sodium ion batteries

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

    Yue, Ji -Li; Yang, Xiao -Qing; Zhou, Yong -Ning; Yu, Xiqian; Bak, Seong -Min; Fu, Zheng -Wen

    2015-10-09

    High rate capability and long cycle life are challenging goals for the development of room temperature sodium-ion batteries. Here we report a new single phase quaternary O3-type layer-structured transition metal oxide Na(NiCoFeTi)1/4O2 synthesized by a simple solid-state reaction as a new cathode material for sodium-ion batteries. It can deliver a reversible capacity of 90.6 mA h g–1 at a rate as high as 20C. At 5C, 75.0% of the initial specific capacity can be retained after 400 cycles with a capacity-decay rate of 0.07% per cycle, demonstrating a superior long-term cyclability at high current density. X-ray diffraction and absorption characterizationmore »revealed reversible phase transformations and electronic structural changes during the Na+ deintercalation/intercalation process. Ni, Co and Fe ions contribute to charge compensation during charge and discharge. Although Ti ions do not contribute to the charge transfer, they play a very important role in stabilizing the structure during charge and discharge by suppressing the Fe migration. Additionally, Ti substitution can also smooth the charge–discharge plateaus effectively, which provides a potential advantage for the commercialization of this material for room temperature sodium-ion batteries.« less

  6. Dielectric properties of <001>-oriented Ba{sub 0.6}Sr{sub 0.4}TiO{sub 3} thin films on polycrystalline metal tapes using biaxially oriented MgO/{gamma}-Al{sub 2}O{sub 3} buffer layers

    SciTech Connect (OSTI)

    Choi, W.; Kang, B.S.; Jia, Q.X.; Matias, V.; Findikoglu, A.T.

    2006-02-06

    We report the growth of <001>-oriented Ba{sub 0.6}Sr{sub 0.4}TiO{sub 3} (BST) thin films on polycrystalline Ni-alloy tapes by pulsed laser deposition using biaxially oriented, ion-beam-assisted deposited (IBAD) MgO and {gamma}-Al{sub 2}O{sub 3} buffer layers. Dielectric constant values of our BST films were up to {approx}85% of those in the epitaxial films prepared under similar conditions on single-crystal MgO substrates. No significant dispersion of the dielectric constant was observed for frequencies from 100 Hz to 1 MHz. These results demonstrate the versatility of using IBAD-textured MgO and {gamma}-Al{sub 2}O{sub 3} buffer layers to integrate highly oriented good-quality BST films with nonsingle-crystalline substrates.

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

    SciTech Connect (OSTI)

    Cook, Bruce A; Harringa, J; Anderegg, A; Russell, A M; Qu, Jun; Blau, Peter Julian; Higdon, Clifton; Elmoursi, Alaa A

    2010-01-01

    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.

  8. A study into effects of CO{sub 2} laser melting of nitrided Ti-6Al-4V alloy

    SciTech Connect (OSTI)

    Mohammed, M.A. [Saudi Aramco, Dhahran (Saudi Arabia); Hashmi, M.S.J. [Dublin City Univ. (Ireland); Yilbas, B.S. [KFDUPM, Dhahran (Saudi Arabia)

    1997-10-01

    Multiple treatment of engineering surfaces can provide improved surface properties that cannot be obtained by a single surface treatment. Consequently, this study investigates the effects of laser melting on the microstructures of plasma nitrided Ti-6Al-4V alloy. The study consists of two parts. In the first part, governing equations pertinent to the laser melting process are developed, and temperature variation across the melted zone is predicted. In the second, an experiment is conducted to nitride the surface of the alloy through plasma nitriding process and to melt the plasma nitrided and the untreated alloy surfaces with a CO{sub 2} laser beam. The resulting metallurgical changes are examined using x-ray diffraction (XRD), energy-dispersive spectrometry (EDS), and scanning electron microscopy (SEM) techniques. It is shown that three distinct nitride layers are formed in the vicinity of the alloy surface prior to the laser melting process, and that after the melting process nitrided species are depleted while cellular and dendritic structures are formed. In addition, the structure consisting of transformed {beta} containing coarse and fine acicular {alpha} is observed in the melted regions.

  9. Wear Mechanism of Chemical Vapor Deposition (CVD) Carbide Insert in Orthogonal Cutting Ti-6Al-4V ELI at High Cutting Speed

    SciTech Connect (OSTI)

    Gusri, A. I.; Che Hassan, C. H.; Jaharah, A. G.

    2011-01-17

    The performance of Chemical Vapor Deposition (CVD) carbide insert with ISO designation of CCMT 12 04 04 LF, when turning titanium alloys was investigated. There were four layers of coating materials for this insert i.e.TiN-Al2O3-TiCN-TiN. The insert performance was evaluated based on the insert's edge resistant towards the machining parameters used at high cutting speed range of machining Ti-6Al-4V ELI. Detailed study on the wear mechanism at the cutting edge of CVD carbide tools was carried out at cutting speed of 55-95 m/min, feed rate of 0.15-0.35 mm/rev and depth of cut of 0.10-0.20 mm. Wear mechanisms such as abrasive and adhesive were observed on the flank face. Crater wear due to diffusion was also observed on the rake race. The abrasive wear occurred more at nose radius and the fracture on tool were found at the feed rate of 0.35 mm/rev and the depth of cut of 0.20 mm. The adhesion wear takes place after the removal of the coating or coating delaminating. Therefore, adhesion or welding of titanium alloy onto the flank and rake faces demonstrates a strong bond at the workpiece-tool interface.

  10. Effect of Co on the thermal stability and magnetic properties of AlNiCo 8 alloys

    SciTech Connect (OSTI)

    Liu, Tao, E-mail: lt9980@hotmail.com; Li, Wei; Zhu, Minggang; Guo, Zhaohui; Li, Yanfeng [Division of Functional Material, Central Iron and Steel Research Institute, Beijing (China)

    2014-05-07

    The magnetic properties, microstructure, and reversible temperature coefficient of magnetic flux of Alnico 8 alloys with the different Co and Ti have been investigated in this paper. The Alnico alloys containing 34, 36, 38, and 40 mass percent cobalt were fabricated by the conventional casting method including thermomagnetic treatment. The transmission electron microscopy (TEM) testing shows that there are more ?1 phases particles with the diameter of less than 10?nm appearing in the matrix with the increasing of the content of Co and Ti. The thermal stability of Alnico 8 alloys deteriorates with the increasing of the content of Co and Ti, which are caused mainly by the decrease of the degree of particle alignment and particle perfection.

  11. Improvement in performance of electrically tunable devices based on nonlinear dielectric SrTiO{sub 3} using a homoepitaxial LaAlO{sub 3} interlayer

    SciTech Connect (OSTI)

    Jia, Q.X.; Findikoglu, A.T.; Reagor, D.; Lu, P.

    1998-08-01

    Improved structural and dielectric properties of nonlinear dielectric SrTiO{sub 3} thin films on LaAlO{sub 3} substrates were accomplished by incorporating a {ital homoepitaxial} LaAlO{sub 3} interlayer between the substrate and the dielectric film. Using this interlayer, the quality factor of SrTiO{sub 3} films with high-temperature superconducting YBa{sub 2}Cu{sub 3}O{sub 7{minus}x} electrodes on LaAlO{sub 3} substrates was improved by more than 50{percent} at 4.2 GHz and 4 K. This improvement, combined with no change in nonlinearity, led to greater than a 50{percent} enhancement of the finesse factor (defined as the product of the quality factor and the fractional shift resonant frequency) for the coplanar waveguide microwave resonators. The reduced planar defect density in the SrTiO{sub 3} films was attributed to this improvement. {copyright} {ital 1998 American Institute of Physics.}

  12. Large magnetic entropy change and adiabatic temperature rise of a Gd{sub 55}Al{sub 20}Co{sub 20}Ni{sub 5} bulk metallic glass

    SciTech Connect (OSTI)

    Xia, L., E-mail: xialei@shu.edu.cn [Key Laboratory for Microstructure and Institute of Materials, Shanghai University, Shanghai 200072 (China); Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hung Hom (Hong Kong); Tang, M. B. [Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 200050 (China); Chan, K. C. [Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hung Hom (Hong Kong); Dong, Y. D. [Key Laboratory for Microstructure and Institute of Materials, Shanghai University, Shanghai 200072 (China)

    2014-06-14

    Gd{sub 55}Al{sub 20}Co{sub 20}Ni{sub 5} bulk metallic glass (BMG) was synthesized by minor Ni substitution for Co in the Gd{sub 55}Al{sub 20}Co{sub 25} BMG in which excellent glass forming ability (GFA) and magneto-caloric effect were reported previously. The Gd{sub 55}Al{sub 20}Ni{sub 20}Co{sub 5} amorphous rod has a similar GFA to the Gd{sub 55}Al{sub 20}Co{sub 25} BMG but exhibits better magnetic properties. The peak value of magnetic entropy change (??S{sub m}{sup peak}) of the Gd{sub 55}Al{sub 20}Co{sub 20}Ni{sub 5} BMG is 9.8 Jkg{sup ?1} K{sup ?1}. The field dependence of ??S{sub m}{sup peak} follows a ??S{sub m}{sup peak}?H{sup 0.85} relationship. The adiabatic temperature rise of the rod is 4.74?K under 5 T and is larger than of other BMGs previously reported. The improved magnetic properties were supposed to be induced by the enhanced interaction between 4f electron in the rare-earth and 3d electron in the transition metal elements by means of a minor Ni substitution for Co.

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

    E-Print Network [OSTI]

    Cook, Lloyd Steven

    1989-01-01

    for internal friction 6. 3 The corstant C TABLE OF CONTENTS (Continued) CONCLUSIONS Page 17 REFERENCES VITA 00 LIST OF TABLES Table l. Alloy Compositions . 2. Measured Densities of Specimens 3. Polynomials for CTE Data 4. Dynamic Young's Modulus... in failure, the mechanical properties of coatings have not been a subject of much concern. Recently, however, plasma sprayed NiCrA1Y coatings have been used as "bond coats", intermediate between an insulating top coat and the protected structural member...

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

    SciTech Connect (OSTI)

    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)

    2014-02-01

    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.

  15. Epitaxial properties of Al-doped ZnO thin films grown by pulsed laser deposition on SrTiO{sub 3}(001)

    SciTech Connect (OSTI)

    Karger, M.; Schilling, M. [Technische Universitaet Braunschweig, Institut fuer Elektrische Messtechnik und Grundlagen der Elektrotechnik, Hans-Sommer-Strasse 66, D-38106 Braunschweig (Germany)

    2005-02-15

    Undoped and Al-doped ZnO films with dopant concentrations of nominally 1% and 10% and a thickness of 100 nm have been grown on SrTiO{sub 3}(001) by pulsed laser deposition at substrate temperatures between 650 deg. C and 820 deg. C. The epitaxial conditions were examined with high pressure in-situ reflection high energy electron diffraction (RHEED) and ex-situ x-ray diffraction (XRD) measurements in different geometries. The films are highly (1120)-oriented with a lattice mismatch between the SrTiO{sub 3}[110] direction and the c-axis of about 3%. Atomic force microscopy (AFM) revealed smooth surfaces with a roughness of d{sub rms}<5 nm and different sized islands.

  16. Corrosion resistance and friction of sintered NdFeB coated with Ti/TiN multilayers

    E-Print Network [OSTI]

    Volinsky, Alex A.

    . In industry, electroplated Ni, Zn, and Ni/Cu/Ni coatings are generally ap- plied because of their good technology, without liquid waste pollu- tion, opposite to electroplating. It can also produce coatingsCorrosion resistance and friction of sintered NdFeB coated with Ti/TiN multilayers Yuanyuan Cheng

  17. Effects of ductile phase volume fraction on the mechanical properties of Ti-Al?Ti metal-intermetallic laminate (MIL) composites

    E-Print Network [OSTI]

    Price, Richard David

    2010-01-01

    ductile behavior, and so should have had the highest fracture toughness.fracture toughness of 31.65MPa?m, indicating primarily ductilefracture toughness decreased steadily with decreasing Al volume fraction, indicating a reduction of ductile

  18. Influence of Bridgman solidification on microstructures and magnetic behaviors of a non-equiatomic FeCoNiAlSi high-entropy alloy

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

    Zuo, Tingting; Yang, Xiao; Liaw, Peter K.; Zhang, Yong

    2015-09-07

    The non-equiatomic FeCoNiAlSi alloy is prepared by the Bridgman solidification (BS) technique at different withdrawal velocities (V = 30, 100, and 200 ?m/s). Various characterization techniques have been used to study the microstructure and crystal orientation. The morphological evolutions accompanying the crystal growth of the alloy prepared at different withdrawal velocities are nearly the same, from equiaxed grains to columnar crystals. The transition of coercivity is closely related to the local microstructure, while the saturation magnetization changes little at different sites. The coercivity can be significantly reduced from the equiaxed grain area to the columnar crystal area when the appliedmore »magnetic field direction is parallel to the crystal growth direction, no matter what is the withdrawal velocity. As a result, the alloy possesses magnetic anisotropy when the applied magnetic field is in different directions.« less

  19. Effects of temperature on serrated flows of Al0.5CoCrCuFeNi high-entropy alloy

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

    Chen, Shuying; Xie, Xie; Chen, Bilin; Qiao, Junwei; Zhang, Yong; Ren, Yang; Dahmen, Karin A.; Liaw, Peter K.

    2015-08-14

    Compression behavior of the Al0.5CoCrCuFeNi high-entropy alloy (HEA) was studied at different temperatures from 673K to 873K at a low strain rate of 5 x 10-5/s to investigate the temperature effect on the mechanical properties and serration behavior. The face-centered cubic (FCC) structure is confirmed at the lower temperature of 673 K and 773 K, and a structure of mixed FCC and body-centered cubic (BCC) is identified at a higher temperature of 873 K after compression tests using high-energy synchrotron X-ray diffraction. As a result, by comparing the stress-strain curves at different temperatures, two opposite directions of serrations types weremore »found, named upward serrations appearing at 673 K and 773 K and downward serrations at 873 K, which may be due to dynamic strain aging.« less

  20. ccsd00003882, Structural relaxations around Ti, Cr and Fe impurities in -Al 2 O 3 probed by x-ray

    E-Print Network [OSTI]

    improve the voltage holdo#11; capability of insulating materials 1 , they are critical for the optical of solids. In the case of dilute elements in single crystals, especially at the K edge of 3d transitionccsd­00003882, version 1 ­ 12 Jan 2005 Structural relaxations around Ti, Cr and Fe impurities

  1. Formation of voids and secondary-phase precipitates in the Fe-16Cr-15Ni-2Mo-1Mn-Ti-Si steel under high-doze neutron irradiation and during post-irradiation annealing

    SciTech Connect (OSTI)

    Portnykh, I. A. Kozlov, A. V.; Shcherbakov, E. N.; Asiptsov, O. I.

    2009-12-15

    The effect of high-dose neutron irradiation on the structural changes in Fe-16Cr-15Ni-2Mo-1Mn-Ti-Si austenitic steel have been investigated. Samples irradiated at temperatures of 390, 500, and 600{sup o} to damage doses of 46, 86, and 46 dpa, respectively, were analyzed by electron microscopy and dilatometry. The quantitative characteristics of radiation voids and secondary-phase precipitates formed under neutron irradiation are obtained. Their behavior upon heating to 700{sup o}C and annealing at this temperature for 2 h is studied. It is shown that annealing leads to the dissociation of small voids, which is accompanied by the growth of large ones. The secondary-phase precipitates are partially dissolved upon annealing, and their volume fraction decreases.

  2. The influence of laser welding parameters on the microstructure and mechanical property of the as-jointed NiTi alloy wires

    E-Print Network [OSTI]

    Zheng, Yufeng

    The influence of laser welding parameters on the microstructure and mechanical property of the as September 2007; accepted 27 November 2007 Available online 4 December 2007 Abstract The Nd:YAG laser welding.%Ni) which had the same diameter of 1 mm. The wires were welded with different parameters, including impulse

  3. Acetic Acid (H3COOH): GaAs; Pb; Ti Hydrochloric Acid (HCl): Al; Cr; Cu; Fe2O3; Ga; GaAs; GaN; In; Fe; Pb; Ni; NiO, Ni2O3; Sn;

    E-Print Network [OSTI]

    Garmestani, Hamid

    ferrocyanide (s) KMnO4 : potassium permanganate (s) FeCl3 : ferric chloride (s) NH4SO5 : ammonium persulfate (s

  4. Enhancing mid-infrared spectral response at the LaAlO{sub 3}/SrTiO{sub 3} interface by magnetic field

    SciTech Connect (OSTI)

    Feng, Xin; Zhao, Kun Xi, Jian-Feng; Xiang, Wen-Feng; Lu, Zhi-Qing; Sun, Qi; Wu, Shi-Xiang; Ni, Hao

    2014-12-15

    Many unexpected properties have been found in the LaAlO{sub 3}/SrTiO{sub 3} heterostructure, but the interaction of the many ground states at its interface remains unclear. Here, we demonstrate an optical property of this n-type heterostructure where the mid-infrared spectral responsivity at the interface is enhanced by an external magnetic field. The field intensity ranged from 0.8 to 6 kOe at a low temperature (19?K) as measured with our spectral response measurement system. Two spectral peaks related to the spin-orbit coupling effect were also observed at wavelengths 2400?nm and 3700?nm. The intriguing phenomena relate to changes in the crystallographic structure and subband structure at the interface.

  5. HRTEM Study of Oxide Nanoparticles in 16Cr-4Al-2W-0.3Ti-0.3Y2O3 ODS Steel

    SciTech Connect (OSTI)

    Hsiung, L; Fluss, M; Wall, M; Kimura, A

    2009-11-18

    Crystal and interfacial structures of oxide nanoparticles in 16Cr-4Al-2W-0.3Ti-0.3Y{sub 2}O{sub 3} ODS ferritic steel have been examined using high-resolution transmission electron microscopy (HRTEM) techniques. Oxide nanoparticles with a complex-oxide core and an amorphous shell were frequently observed. The crystal structure of complex-oxide core is identified to be mainly monoclinic Y{sub 4}Al{sub 2}O{sub 9} (YAM) oxide compound. Orientation relationships between the oxide and matrix are found to be dependent on the particle size. Large particles (> 20 nm) tend to be incoherent and have a spherical shape, whereas small particles (< 10 nm) tend to be coherent or semi-coherent and have a faceted interface. The observations of partially amorphous nanoparticles lead us to propose three-stage mechanisms to rationalize the formation of oxide nanoparticles containing core/shell structures in as-fabricated ODS steels.

  6. Tunability of conduction at the LaAlO{sub 3}/SrTiO{sub 3} heterointerface: Thickness and compositional studies

    SciTech Connect (OSTI)

    Breckenfeld, E.; Bronn, N.; Mason, N.; Martin, L. W.

    2014-09-22

    The role of chemistry, film thickness, and oxygen pressure in influencing the electrical and thermal transport properties of LaAlO{sub 3}/SrTiO{sub 3} heterointerfaces is explored. Unit-cell precise growth was accomplished for films between 3 and 160 unit cells thick using reflection high-energy electron diffraction-assisted pulsed-laser deposition. Subsequent temperature-dependent studies of electrical resistivity reveal three important observations: (1) by tuning the laser fluence, we can systematically tune the interfacial conductance in a step-wise manner in this system, (2) all films exhibit a critical thickness of 3–4 unit cells for the onset of conduction, and (3) the nature of the conductance is highly influenced by the stoichiometry of the LaAlO{sub 3} film with La-deficient samples showing dramatic changes with thickness, while stoichiometric and La-excess films show little dependence. Time-domain thermoreflectance studies show a diminished interfacial thermal conductance for the La-deficient films when compared to La-excess and stoichiometric films, suggesting that the interfacial conductance is more influenced by extrinsic factors such as oxygen deficiency.

  7. 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 (OSTI)

    Janka, Oliver; Baumbach, Ryan E.; Thompson, Joe D.; Bauer, Eric D.; Kauzlarich, Susan M.

    2013-09-15

    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.

  8. Study of the microstructure of plasma sprayed coatings obtained from Al{sub 2}O{sub 3}–13TiO{sub 2} nanostructured and conventional powders

    SciTech Connect (OSTI)

    Góral, A.; ?órawski, W.; Lity?ska-Dobrzy?ska, L.

    2014-10-15

    The microstructure of coatings obtained from nanostructured or conventional Al{sub 2}O{sub 3}–13TiO{sub 2} powders and deposited by plasma spraying technique on low-carbon steel was examined by transmission electron microscopy techniques. The dominating phase in both coatings was ?-Al{sub 2}O{sub 3} phase. It has been observed that the grains of ?-Al{sub 2}O{sub 3} grew in various shapes and sizes, that are particularly visible in the case of coating sprayed from nanostructured powder. The coatings obtained from the fully melted conventional powders exhibited a typical lamellar microstructure, into which the strips of TiO{sub 2} phase were extended. The microstructure of coatings produced from agglomerates of nanostructured particles also revealed the regions consisting of partially melted ?-Al{sub 2}O{sub 3} powders surrounded by the net-like structure formed from fully melted oxides that improved the coating properties. Along with the observed morphology diversity some changes in the chemical composition on the cross sections of obtained coatings have been also noticed. - Highlights: • Plasma sprayed Al{sub 2}O{sub 3}–13TiO{sub 2} coatings reveal diversity of microstructure. • Microstructure of conventional coating was formed from fully melted crushed powders. • Nanostructured coating contains completely and partially melted initial agglomerates.

  9. Femtosecond laser-induced periodic surface structure on the Ti-based nanolayered thin films

    SciTech Connect (OSTI)

    Petrovi?, Suzana M.; Gakovi?, B.; Peruško, D.; Stratakis, E.; Department of Materials Science and Technology, University of Crete, 710 03 Heraklion, Crete ; Bogdanovi?-Radovi?, I.; ?ekada, M.; Fotakis, C.; Department of Physics, University of Crete, 714 09 Heraklion, Crete ; Jelenkovi?, B.

    2013-12-21

    Laser-induced periodic surface structures (LIPSSs) and chemical composition changes of Ti-based nanolayered thin films (Al/Ti, Ni/Ti) after femtosecond (fs) laser pulses action were studied. Irradiation is performed using linearly polarized Ti:Sapphire fs laser pulses of 40 fs pulse duration and 800 nm wavelength. The low spatial frequency LIPSS (LSFL), oriented perpendicular to the laser polarization with periods slightly lower than the irradiation wavelength, was typically formed at elevated laser fluences. On the contrary, high spatial frequency LIPSS (HSFL) with uniform period of 155 nm, parallel to the laser light polarization, appeared at low laser fluences, as well as in the wings of the Gaussian laser beam distribution for higher used fluence. LSFL formation was associated with the material ablation process and accompanied by the intense formation of nanoparticles, especially in the Ni/Ti system. The composition changes at the surface of both multilayer systems in the LSFL area indicated the intermixing between layers and the substrate. Concentration and distribution of all constitutive elements in the irradiated area with formed HSFLs were almost unchanged.

  10. Influence of topography and Co domain walls on the magnetization reversal of the FeNi layer in FeNi/Al2O3/Co magnetic tunnel junctions

    E-Print Network [OSTI]

    Kuch, Wolfgang

    Influence of topography and Co domain walls on the magnetization reversal of the FeNi layer in Fe situated on and situated be- tween steps is large. To test the influence of the topography microscopic view of the influence of the substrate-induced layer topography on the magnetization reversal

  11. Enthalpy of mixing of liquid Ni-Zr and Cu-Ni-Zr alloys

    SciTech Connect (OSTI)

    Witusiewicz, V.T.; Sommer, F.

    2000-04-01

    Since the Al-Cu-Ni-Zr system is a basis for the production of bulk amorphous materials by rapid solidification techniques from the liquid state, it is of great scientific interest to determine the partial and the integral thermodynamic functions of liquid and undercooled liquid alloys. Such data, as was pointed out previously, are important in order to understand their extremely good glass-forming ability in multicomponent metallic systems as well as for processing improvements. In order to measure the thermodynamic properties of the Al-Cu-Ni-Zr quaternary, it is necessary to have reliable thermochemical data for its constituent canaries and ternaries first. In a series of articles, the authors have reported in detail the thermodynamic properties of liquid Al-Cu, Al-Ni, Cu-Ni, Cu-Zr, Al-Zr, Al-Cu-Ni, and Al-Cu-Zr alloys. This article deals with the direct calorimetric measurements of the partial and the integral enthalpies of mixing of liquid Ni-Zr and Cu-Ni-Zr alloys and the heat capacity of liquid Ni{sub 26}Zr{sub 74}. In a subsequent article, the authors will present similar data for the liquid ternary Al-Ni-Zr and for the liquid quaternary Al-Cu-Ni-Zr alloys.

  12. 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

    SciTech Connect (OSTI)

    Ritchie, IAltenberger, RKNalla, YSano LWagner, RO

    2012-04-01

    The effect of surface treatment on the stress/life fatigue behavior of a titanium Ti-6Al-4V turbine fan blade alloy is investigated in the regime of 102 to 106 cycles to failure under fully reversed stress-controlled isothermal push-pull loading between 25? and 550?C at a frequency of 5 Hz. Specifically, the fatigue behavior was examined in specimens in the deep-rolled and laser-shock peened surface conditions, and compared to results on samples in the untreated (machined and stress annealed) condition. Although the fatigue resistance of the Ti-6Al-4V alloy declined with increasing test temperature regardless of surface condition, deep-rolling and laser-shock peening surface treatments were found to extend the fatigue lives by factors of more than 30 and 5-10, respectively, in the high-cycle and low-cycle fatigue regimes at temperatures as high as 550?C. At these temperatures, compressive residual stresses are essentially relaxed; however, it is the presence of near-surface work hardened layers, with a nanocystalline structure in the case of deep-rolling and dense dislocation tangles in the case of laser-shock peening, which remain fairly stable even after cycling at 450?-550?C, that provide the basis for the beneficial role of mechanical surface treatments on the fatigue strength of Ti-6Al-4V at elevated temperatures.

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

    E-Print Network [OSTI]

    Sparks, Donald L.

    oxide minerals: A time-resolved XAFS study ANDR´E M. SCHEIDEGGER,1,2, * DANIEL G. STRAWN,1 GERALDINE M of sorption decreased significantly and depended on the type of mineral surface. For the Ni with increasing reaction time. Our study suggests that three phenomena occur at the mineral/liquid interface: (1

  14. Bench- and Pilot-Scale Studies of Reaction and Regeneration of Ni-Mg-K/Al2O3 for Catalytic Conditioning of Biomass-Derived Syngas

    SciTech Connect (OSTI)

    Magrini-Bair, K. A.; Jablonski, W. S.; Parent, Y. O.; Yung, M. M.

    2012-05-01

    The National Renewable Energy Laboratory (NREL) is collaborating with both industrial and academic partners to develop technologies to help enable commercialization of biofuels produced from lignocellulosic biomass feedstocks. The focus of this paper is to report how various operating processes, utilized in-house and by collaborators, influence the catalytic activity during conditioning of biomass-derived syngas. Efficient cleaning and conditioning of biomass-derived syngas for use in fuel synthesis continues to be a significant technical barrier to commercialization. Multifunctional, fluidizable catalysts are being developed to reform undesired tars and light hydrocarbons, especially methane, to additional syngas, which can improve utilization of biomass carbon. This approach also eliminates both the need for downstream methane reforming and the production of an aqueous waste stream from tar scrubbing. This work was conducted with NiMgK/Al{sub 2}O{sub 3} catalysts. These catalysts were assessed for methane reforming performance in (i) fixed-bed, bench-scale tests with model syngas simulating that produced by oak gasification, and in pilot-scale, (ii) fluidized tests with actual oak-derived syngas, and (iii) recirculating/regenerating tests using model syngas. Bench-scale tests showed that the catalyst could be completely regenerated over several reforming reaction cycles. Pilot-scale tests using raw syngas showed that the catalyst lost activity from cycle to cycle when it was regenerated, though it was shown that bench-scale regeneration by steam oxidation and H{sub 2} reduction did not cause this deactivation. Characterization by TPR indicates that the loss of a low temperature nickel oxide reduction feature is related to the catalyst deactivation, which is ascribed to nickel being incorporated into a spinel nickel aluminate that is not reduced with the given activation protocol. Results for 100 h time-on-stream using a recirculating/regenerating reactor suggest that this type of process could be employed to keep a high level of steady-state reforming activity, without permanent deactivation of the catalyst. Additionally, the differences in catalyst performance using a simulated and real, biomass-derived syngas stream indicate that there are components present in the real stream that are not adequately modeled in the syngas stream. Heavy tars and polycyclic aromatics are known to be present in real syngas, and the use of benzene and naphthalene as surrogates may be insufficient. In addition, some inorganics found in biomass, which become concentrated in the ash following biomass gasification, may be transported to the reforming reactor where they can interact with catalysts. Therefore, in order to gain more representative results for how a catalyst would perform on an industrially-relevant scale, with real contaminants, appropriate small-scale biomass solids feeders or slip-streams of real process gas should be employed.

  15. Ni-YSZ films deposited by reactive magnetron sputtering for SOFC applications E. Rezugina(*), A.L. Thomann, H. Hidalgo, P. Brault(*), V. Dolique, Y. Tessier

    E-Print Network [OSTI]

    Boyer, Edmond

    a single Ni/Zr/Y metallic target at rates as high as 4µm.h-1 . Tailoring both DC pulsed power and oxygen Technology 204 (2010) 2376-2380" DOI : 10.1016/j.surfcoat.2010.01.006 #12;2 1. Introduction Solid Oxide Fuel for a low operating cost [1]. A fuel cell is a device for direct conversion of chemical energy

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

    E-Print Network [OSTI]

    Cho, Jaephil

    increases to 2.75V (2.85V vs. graphite), its discharge capacity decreases to 120 mAh/g, which corresponds for the irreversible capacity of the Li-ion cell using LiCoO2 and natural graphite as cathode and anode materials the complete decomposition of the Li2NiO2. 1. Introduction Most Li secondary batteries use LiCoO2 as a cathode

  17. Fabrication of CuAl{sub 1?x}M{sub x}O{sub 2} (M = Fe, Cr)/Ni film delafossite compounds using spin coating and their microstructure and dielectric constant

    SciTech Connect (OSTI)

    Diantoro, Markus, E-mail: m-diantoro@yahoo.com; Yuwita, Pelangi Eka, E-mail: m-diantoro@yahoo.com; Olenka, Desyana, E-mail: m-diantoro@yahoo.com; Nasikhudin, E-mail: m-diantoro@yahoo.com [Jurusan Fisika, Fakultas Matematika dan Ilmu Pengetahuan Alam, Universitas Negeri Malang, Jalan Semarang 5, Malang 65145 (Indonesia)

    2014-09-25

    The discovery of delafossite compound has encouraged more rapid technological developments particularly in transparent electronic devices. Copper oxide-based transparent thin films delafossite semiconductor recently give much attention in the field of optoelectronic technology, after the discovery of p-type CuAlO{sub 2}. The potential applications of a p-type semiconductor transparent conductive oxides (TCO) have been applied in broad field of optoelectronics. To explore a broad physical properties interms of magnetic conducting subtitution is understudied. In this work we report the fabrication of delafossite film on Ni substrate and their characterization of CuAl{sub 1?x}M{sub x}O{sub 2} delafossite compounds doped with Cr{sup 3+} and Fe{sup 3+} from the raw material of Cu(NO{sub 3}){sub 2}@@‡3H{sub 2}O, Al(NO{sub 3}){sub 3}@@‡9H{sub 2}O, Fe(NO{sub 3}){sub 3}@@‡9H{sub 2}O and Cr(NO{sub 3}){sub 3}@@‡9H{sub 2}O. The films were prepared using spin coating through a sol-gel technique at various concentrations of x = 0, 0.03, 0.04, and 0.05 for chromium and x = 0, 0.02, 0.04, 0.06, and 0.08 for iron doped. Crystal and microstructure were characterized by means of Cu-K? Bragg-Brentano X-RD followed by High Score Plus and SEM-EDAX. The dielectric constants of the films were characterized using LCR meter. It was found that the CuAl{sub 1?x}M{sub x}O{sub 2}/Ni delafossite films were successfully fabricated. The CuAl{sub 1?x}Fe{sub x}O{sub 2} compound crystallized with lattice parameters of a = b ranged from 2.8603 Å to 2.8675 Å and c ranged from 16.9576 to 17.0763 Å. The increase of the dopant give rise to the increase of the lattice parameters. Since iron has bigger ionic radius (69 pm) than original site of Al{sup 3+} with radius of 53 pm the crystal volume lattice also increase. Further analyses of increasing volume of the crystal, as expected, affected to the decreasing of its dielectric constant. The similar trends also shown by Cr{sup 3+} doped of CuAl{sub 1?x}Cr{sub x}O{sub 2} films with smaller effects.

  18. Non-equilibrium synthesis by laser cladding of Ni, Nb and Mg alloys for improved environmental resistance. Final report, Nov 88-Oct 91

    SciTech Connect (OSTI)

    Mazumder, J.; Kar, A.; Tewari, S.K.; Ribaudo, C.R.

    1992-03-30

    The technique of laser surface modification provides a unique means of synthesizing novel nonequilibrium materials in near net shape. The goal of the proposed program is to develop a science base for synthesis of nonequilibrium metastable alloys by laser processing. This report summarizes experimental and theoretical studies carried out during the period of November 1988 to October 1991 on laser surface modification of Ni, Nb and Mg alloys for improved environmental resistance at high temperature. A microstructural evolution model of NbAl3 was developed and the relative oxidation resistance of claddings of several Nb-based alloys were investigated. Initial work with V revealed that V increases the ductility, and decreases the oxidation resistance of laser clad NbAl3. Oxidation behavior of alloys with Ti, B and Hf as a ternary alloy addition were identified: Oxidation tests at 800, 1200, and 1400 deg C were conducted on NbAl3-0 at %B (O B), NbAl3-0.5 at %B (0.5 B), NbAl3-1.0 at %B (1.0 B), NbAl3-1.0 at B-3 at %Ti (3 Ti), NbAl3-1.0 at %B-6 at %Ti (6 Ti) and NbAl3-1.5 at %Hf (1.5 Hf) alloys. An external layer of x-alumina formed on samples of alloys 0.5 B and 1.0 B isothermally oxidized in air at 800, 1200 and 1400 deg C. A mixture of alumina and NbAl04 formed on the samples of alloy 0 B exposed to same testing conditions.

  19. Pressure tuned ferroelectric reentrance in nano-BaTiO3 ceramics J. L. Zhu, S. Lin, S. M. Feng, L. J. Wang, Q. Q. Liu et al.

    E-Print Network [OSTI]

    Cao, Wenwu

    Pressure tuned ferroelectric reentrance in nano-BaTiO3 ceramics J. L. Zhu, S. Lin, S. M. Feng, L. J polarization and strain of Bi-based ceramic composites J. Appl. Phys. 112, 124109 (2012) Nonlinear dielectric (2012) The dominance of paramagnetic loss in microwave dielectric ceramics at cryogenic temperatures

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

    SciTech Connect (OSTI)

    Osuka, Hisao; Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5, Takayama-cho, Ikoma-shi, Nara 630-0192 ; Shomura, Yasuhito; Komori, Hirofumi; Shibata, Naoki; Nagao, Satoshi; Higuchi, Yoshiki; CREST, JST, Gobancho, Chiyoda-ku, Tokyo 102-0076 ; Hirota, Shun; CREST, JST, Gobancho, Chiyoda-ku, Tokyo 102-0076

    2013-01-04

    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.

  1. Coexistence of Magnetic Order and Two-dimensional Superconductivity at LaAlO3/SrTiO3 Interfaces

    E-Print Network [OSTI]

    Li, Lu

    A two dimensional electronic system forms at the interface between the band insulators LaAlO[subscript 3]

  2. Ni(III)/(IV) Bis(dicarbollide) as a Fast, Noncorrosive Redox Shuttle for Dye-Sensitized Solar Cells

    SciTech Connect (OSTI)

    Li, Tina C.; Spokoyny, Alexander M.; She, Chunxing; Farha, Omar K.; Mirkin, Chad; Marks, Tobin J.; Hupp, Joseph T.

    2010-01-01

    Nickel bis(dicarbollide) is used as a fast, one-electron outer sphere redox couple in dye-sensitized solar cells. Device performances with this anionic shuttle are investigated with different electrolyte concentrations and additives, using only 0.030 M of the Ni(III) bis(dicarbollide) to efficiently regenerate the ruthenium dye. Atomic layer deposition of Al{sub 2}O{sub 3} on the nanoparticulate TiO{sub 2} photoanodes is further used to improve device performances, increasing current densities almost 2-fold and attaining power conversion efficiencies 10× greater than its metallocene analogue, ferrocene/ferrocenium. Open-circuit voltage decay is used to probe the kinetics of the Ni(III)/(IV) bis(dicarbollide) redox couple, and electron interception is found to be 10{sup 3}× slower than ferrocene/ferrocenium, explaining the large discrepancy in open-circuit voltage potentials between these two redox shuttles.

  3. Ni(III)/(IV) Bis(dicarbollide) as a Fast, Noncorrosive Redox Shuttle for Dye-Sensitized Solar Cells

    SciTech Connect (OSTI)

    Li, Tina C. [Northwestern Univ., Evanston, IL (United States); Spokoyny, Alexander M. [Northwestern Univ., Evanston, IL (United States); Chunxing, She [Northwestern Univ., Evanston, IL (United States); Farha, Omar K. [Northwestern Univ., Evanston, IL (United States); Mirkin, Chad A. [Northwestern Univ., Evanston, IL (United States); Marks, Tobin J. [Northwestern Univ., Evanston, IL (United States); Hupp, Joseph T. [Northwestern Univ., Evanston, IL (United States)

    2010-01-01

    Nickel bis(dicarbollide) is used as a fast, one-electron outer sphere redox couple in dye-sensitized solar cells. Device performances with this anionic shuttle are investigated with different electrolyte concentrations and additives, using only 0.030 M of the Ni(III) bis(dicarbollide) to efficiently regenerate the ruthenium dye. Atomic layer deposition of Al{sub 2}O{sub 3} on the nanoparticulate TiO{sub 2} photoanodes is further used to improve device performances, increasing current densities almost 2-fold and attaining power conversion efficiencies ?10× greater than its metallocene analogue, ferrocene/ferrocenium. Open-circuit voltage decay is used to probe the kinetics of the Ni(III)/(IV) bis(dicarbollide) redox couple, and electron interception is found to be ?10{sup 3}× slower than ferrocene/ferrocenium, explaining the large discrepancy in open-circuit voltage potentials between these two redox shuttles.

  4. Production of {sup 44}Ti in neutrino-driven aspherical supernova explosions

    SciTech Connect (OSTI)

    Fujimoto, Shin-ichiro [Kumamoto National College of Technology, 2659-2 Suya, Goshi 861-1102 (Japan); Ono, Masaomi; Hashimoto, Masa-aki [Department of Physics, School of Sciences, Kyushu University, Fukuoka 810-8560 (Japan); Kotake, Kei [National Astronomical Observatory Japan, 2-21-1, Osawa, Mitaka, Tokyo, 181-8588 (Japan)

    2014-05-02

    We examine the synthesis of {sup 44}Ti in a neutrino-driven aspherical supernova (SN), focusing on reaction rates related to {sup 44}Ti and rotation of a progenitor. We have performed 2D hydrodynamic simulations of SN of a 15M{sub ?} progenitor, whose angular velocity is manually set to be a cylindrical distribution and have followed explosive nucleosynthesis in the ejecta. We find that the faster rates of {sup 40}Ca(?,?){sup 44}Ti and the slower rate of {sup 44}Ti(?,p){sup 47}V lead to more massive ejection of {sup 44}Ti and {sup 56}Ni and larger ratios <{sup 44}Ti/{sup 56}Ni>. Faster rotation also results in more massive ejection of {sup 44}Ti and {sup 56}Ni. Ratios <{sup 44}Ti/{sup 56}Ni> are however independent from rotation. Large masses of {sup 44}Ti and large ratios <Ti/{sup 56}Ni> observed in SN 1987A and Cas A (> 1O{sup ?4}M{sub ?} and 1-2 respectively) are not realized in all the models.

  5. Ni(III)/(IV) Bis(dicarbollide) as a Fast, Noncorrosive Redox Shuttle for Dye-Sensitized Solar Cells

    E-Print Network [OSTI]

    multiple redox transformations involving net charges of -2, -1, and 0, with Ni(II), Ni(III) (3), and Ni at the electrolyte interface. Previous DSC Fc/Fc+ couple work showed that dark currents can be suppressed by TiO2/Fc+ vs SCE (translating to a smaller potential difference between the dark electrode and quasi

  6. Investigations on the effects of multi-layered coated inserts in machining Ti6Al4V alloy with experiments and finite element simulations

    E-Print Network [OSTI]

    Ozel, Tugrul

    be increased by improving cutting tool materials and coatings [3,4]. Cubic boron nitride (cBN) material offersAlN coated tungsten carbide inserts is compared in terms of cutting forces and tool wear. In addition, finite­6Al­4V alloy. Positive tool geometry WC/Co inserts are coated by cBN using a PVD system. Machining

  7. Microstructure and dielectric properties of Ba{sub 1-x}Sr{sub x}TiO{sub 3} films grown on LaAlO{sub 3} substrates

    SciTech Connect (OSTI)

    Gim, Y.; Hudson, T.; Fan, Y.; Kwon, C.; Findikoglu, A. T.; Gibbons, B. J.; Park, B. H.; Jia, Q. X.

    2000-08-21

    We report a systematic study of the microstructure and dielectric properties of barium strontium titanate, Ba{sub 1-x}Sr{sub x}TiO{sub 3}, films grown by laser ablation on LaAlO{sub 3} substrates, where x=0.1-0.9 at an interval of 0.1. X-ray diffraction analysis shows that when x<0.4, the longest unit-cell axis is parallel to the plane of the substrate but perpendicular as x approaches 1. Dielectric constant versus temperature measurements show that the relative dielectric constant has a maximum value and that the peak temperatures corresponding to the maximum relative dielectric constant are about 70 degree sign C higher when x{<=}0.4 but similar when x>0.4, compared with the peak temperatures of the bulk Ba{sub 1-x}Sr{sub x}TiO{sub 3}. At room temperature, the dielectric constant and tunability are relatively high when x{<=}0.4 but start to decrease rapidly as x increases. (c) 2000 American Institute of Physics.

  8. Breakup of the projectile in [sup 16]O-induced reactions on [sup 27]Al, [sup 58]Ni, and [sup 197]Au targets around 100 MeV/nucleon

    SciTech Connect (OSTI)

    Badala, A.; Barbera, R.; Palmeri, A.; Pappalardo, G.S. (Istituto Nazionale di Fisica Nucleare, Sezione di Catania, Corso Italia 57, 95129 Catania (Italy)); Riggi, F. (Istituto Nazionale di Fisica Nucleare, Sezione di Catania, Corso Italia 57, 95129 Catania (Italy) Dipartimento di Fisica dell'Universita di Catania, Corso Italia 57, 95129 Catania (Italy))

    1993-08-01

    The spatial correlation among the four He ions coming from the disassembly of the [sup 16]O projectile on [sup 27]Al, [sup 58]Ni, and [sup 197]Au targets has been studied at 94 MeV/nucleon. Charged particles have been detected by a multielement array of plastic scintillators covering the angular domain between 3[degree] and 150[degree]. Standard relativistic kinematics has been used to reconstruct the excitation energy of the primary projectilelike nucleus ([ital E][sub PLN][sup *]). Mean values of this quantity are found independent of the target mass and the comparison with existing similar data taken at lower bombarding energies shows a saturation of [ital E][sub PLN][sup *] around 3 MeV/nucleon. An event-by-event analysis has been performed in order to study the distributions of some global variables such as coplanarity, sphericity, and relative angle, helpful in the understanding of the topological characteristics of the process and in the evaluation of its time scale. Experimental data have also been compared with the results of Monte Carlo simulations based on different reaction mechanisms and it is possible to conclude that sequential emission of the fragments is preferred.

  9. Ab initio study of structural, electronic, magnetic alloys: XTiSb (X = Co, Ni and Fe)

    SciTech Connect (OSTI)

    Ibrir, M. Berri, S.; Lakel, S.; Alleg, S.; Bensalem, R.

    2015-03-30

    Structural, electronic and magnetic properties of three semi-Heusler compounds of CoTiSb, NiTiSb and FeTiSb were calculated by the method (FP-LAPW) which is based on the DFT code WIEN2k. We used the generalized gradient approximation (GGA (06)) for the term of the potential exchange and correlation (XC) to calculate structural properties, electronic properties and magnetic properties. Structural properties obtained as the lattice parameter are in good agreement with the experimental results available for the electronic and magnetic properties was that: CoTiSb is a semiconductor NiTiSb is a metal and FeTiSb is a half-metal ferromagnetic.

  10. Transition-metal and metalloid substitutions in L1(0)-ordered FeNi

    SciTech Connect (OSTI)

    Manchanda, P; Skomski, R; Bordeaux, N; Lewis, LH; Kashyap, A

    2014-05-07

    The effect of atomic substitutions on the magnetization, exchange, and magnetocrystalline anisotropy energy of L1(0)-ordered FeNi (tetrataenite) is computationally investigated. The compound naturally occurs in meteorites but has attracted renewed attention as a potential material for permanent magnets, and elemental additives will likely be necessary to facilitate the phase formation. Our density functional theory calculations use the Vienna ab-initio simulation package, applied to 4-atom unit cells of Fe2XNi and 32-atom supercells (X = Al, P, S, Ti, V, Cr, Mn, Fe, Co). While it is found that most additives deteriorate the magnetic properties, there are exceptions: excess substitutional Fe and Co additions improve the magnetization, whereas Cr, S, and interstitial B additions improve the magnetocrystalline anisotropy. (C) 2014 AIP Publishing LLC.

  11. Transition-metal and metalloid substitutions in L1{sub 0}-ordered FeNi

    SciTech Connect (OSTI)

    Manchanda, Priyanka; Skomski, Ralph; Bordeaux, N.; Lewis, L. H.; Kashyap, Arti

    2014-05-07

    The effect of atomic substitutions on the magnetization, exchange, and magnetocrystalline anisotropy energy of L1{sub 0}-ordered FeNi (tetrataenite) is computationally investigated. The compound naturally occurs in meteorites but has attracted renewed attention as a potential material for permanent magnets, and elemental additives will likely be necessary to facilitate the phase formation. Our density functional theory calculations use the Vienna ab-initio simulation package, applied to 4-atom unit cells of Fe{sub 2}XNi and 32-atom supercells (X?=?Al, P, S, Ti, V, Cr, Mn, Fe, Co). While it is found that most additives deteriorate the magnetic properties, there are exceptions: excess substitutional Fe and Co additions improve the magnetization, whereas Cr, S, and interstitial B additions improve the magnetocrystalline anisotropy.

  12. Giant resonances in Ti-46,Ti-48 

    E-Print Network [OSTI]

    Tokimoto, Y.; Lui, Y. -W; Clark, H. L.; John, B.; Chen, X.; Youngblood, David H.

    2006-01-01

    The giant resonance region from 9 MeV < E-x < 55 MeV in Ti-46 and Ti-48 has been studied with inelastic scattering of 240 MeV alpha particles at small angles including 0(degrees). Isoscalar monopole strength in Ti-46 (Ti-48) was found corresponding...

  13. Analysis of weak-beam contrast from SESF/SISF fault pairs associated with {1/2}[{l{underscore}angle}112] superdislocations in TiAl[Superlattice Extrinsic and Intrinsic Fault Pairs

    SciTech Connect (OSTI)

    Kumar, M.; Sriram, S.; Schwartz, A.J.; Vasudevan, V.K.

    1999-07-01

    The diffraction contrast from dissociated {1/2}[{l{underscore}angle}112] superdislocations in {gamma}-TiAl intermetallic alloy cannot always be analyzed using conventional rules of diffraction contrast. In particular, the configuration involving three similar Shockley partials on adjacent planes has often been ruled out due to the absence of fringes indicating the presence of stacking faults. In order to determine the dissociated configuration, weak-beam transmission electron microscope observations of edge-oriented {1/2}[{l{underscore}angle}112] superdislocations have been correlated with computer simulated images. Dissociation of these superdislocations into three similar 1/6[{l{underscore}angle}112] partial dislocations bounding a superlattice extrinsic and intrinsic stacking fault pair has been consequently determined from these analyses. It has been found that diffraction contrast alone cannot distinguish between the various configurations that lead to the formation of the fault pair, but the formation of an antiphase boundary or complex stacking fault linked dissociation or locking by stair rod dislocations can be ruled out.

  14. Structural Underpinnings of the Enhanced Cycling Stability upon Al-Substitution in LiNi0.45Mn0.45Co0.1-yAlyO2 Positive Electrode Materials for Li-ion Batteries

    E-Print Network [OSTI]

    Conry, Thomas E.

    2013-01-01

    materials for Li-ion batteries Thomas E. Conry, a,b Apurvamaterials in Li-ion batteries. Synchrotron-based high-materials for Li-ion batteries. LiNi z Mn z Co 1-2z O 2 (NMC

  15. Electric modulation of magnetization at the BaTiO3/La0.67Sr0.33MnO3 H. Lu, T. A. George, Y. Wang, I. Ketsman, J. D. Burton et al.

    E-Print Network [OSTI]

    Eom, Chang Beom

    Electric modulation of magnetization at the BaTiO3/La0.67Sr0.33MnO3 interfaces H. Lu, T. A. George. Phys. 113, 043914 (2013) Electrical control of magnetic reversal processes in magnetostrictive://apl.aip.org/about/rights_and_permissions #12;Electric modulation of magnetization at the BaTiO3/La0.67Sr0.33MnO3 interfaces H. Lu,1 T. A

  16. A=20Al, etc. (1998TI06)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01)72AJ02)

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

    SciTech Connect (OSTI)

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

    2012-06-01

    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.

  18. Ni Ni: University of California - Los Angeles

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shinesSolarNew scholarshipThreeFebruary 2015 ESH&SCSU - EnergyNi Ni:

  19. Precipitation in 18 wt% Ni maraging steel of grade 350

    SciTech Connect (OSTI)

    Tewari, R.; Mazumder, S.; Batra, I.S.; Dey, G.K.; Banerjee, S.

    2000-03-14

    The evolution of precipitates in maraging steel of grade 350 was studied using the complementary techniques of small angle X-ray scattering (SACS) and transmission electron microscopy (TEM). These investigations revealed that ageing the steel at 703 K involved a rhombohedral distortion of the supersaturated b.c.c. martensite accompanied by the appearance of diffuse {omega}-like structures. This was followed by the appearance of well-defined {omega} particles containing chemical order. At the ageing temperature of 783 K, Ni{sub 3}(Ti,Mo) precipitates were the first to appear with a growth exponent of 1/3. The values of the Pored exponent obtained from the SAXS profiles indicated that the {omega} particles, formed below 723 K, had diffuse interfaces up to an ageing time of 48 h. On the other hand, Ni{sub 3}(Ti,Mo) precipitates, formed above 723 K, developed sharp interfaces in just about an hour. Also, the steel exhibited scaling in phase separation both at 703 and 783 K, but only during the early stages. Through this study it was established that at temperatures of ageing less than 723 K, evolution of {omega} particles takes place through the collapse of the unstable b.c.c. lattice and, at temperatures above 723 K, precipitation of A{sub 3}B type of phases through the mechanism of clustering and ordering of atomic species. Sharp interfaces develop rather quickly when the mechanism of precipitation involves development and amplification of a concentration wave along as in the nucleation of Ni{sub 3}(Ti,Mo) at 783 K than when an interplay of both the displacement and concentration waves is required as in the evolution of {omega} at 703 K. These results indicate towards the possibility of existence of two separate time-temperature-transformation (TTT) curves, one for the evolution of {omega}-phase and another for nucleation and growth of Ni{sub 3}(Ti,Mo).

  20. Conversion of CH{sub 4}/CO{sub 2} to syngas over Ni-Co/Al{sub 2}O{sub 3}-ZrO{sub 2} nanocatalyst synthesized via plasma assisted co-impregnation method: Surface properties and catalytic performance

    SciTech Connect (OSTI)

    Rahemi, Nader; Haghighi, Mohammad; Reactor and Catalysis Research Center , Sahand University of Technology, P.O. Box 51335-1996, Sahand New Town, Tabriz ; Akbar Babaluo, Ali; Nanostructure Material Research Center , Sahand University of Technology, P.O. Box 51335-1996, Sahand New Town, Tabriz ; Fallah Jafari, Mahdi; Khorram, Sirous

    2013-09-07

    Ni/Al{sub 2}O{sub 3} catalyst promoted by Co and ZrO{sub 2} was prepared by co-impregnation method and treated with glow discharge plasma. The catalytic activity of the synthesized nanocatalysts has been tested toward conversion of CH{sub 4}/CO{sub 2} to syngas. The physicochemical characterizations like XRD, EDX, FESEM, TEM, BET, FTIR, and XPS show that plasma treatment results in smaller particle size, more surface concentration, and uniform morphology. The dispersion of nickel in plasma-treated nanocatalyst was also significantly improved, which was helpful for controlling the ensemble size of active phase atoms on the support surface. Improved physicochemical properties caused 20%–30% enhancement in activity of plasma-treated nanocatalyst that means to achieve the same H{sub 2} or CO yield, the plasma-treated nanocatalyst needed about 100 °C lower reaction temperature. The H{sub 2}/CO ratio got closer to 1 at higher temperatures and finally at 850 °C H{sub 2}/CO = 1 is attained for plasma-treated nanocatalyst. Plasma-treated nanocatalyst due to smaller Ni particles and strong interaction between active phase and support has lower tendency to keep carbon species on its structure and hence excellent stability can be observed for this catalyst.

  1. LARGE FORCE SHAPE MEMORY ALLOY LINEAR ACTUATOR JOS R. SANTIAGO ANADN

    E-Print Network [OSTI]

    Florida, University of

    .............................................................................................. 13 Ni-Ti (Nitinol

  2. Aliovalent titanium substitution in layered mixed Li Ni-Mn-Co oxides for lithium battery applications

    SciTech Connect (OSTI)

    Kam, Kinson; Doeff, Marca M.

    2010-12-01

    Improved electrochemical characteristics are observed for Li[Ni1/3Co1/3-yMyMn1/3]O2 cathode materials when M=Ti and y<0.07, compared to the baseline material, with up to 15percent increased discharge capacity.

  3. Data regression using the TI's calculators TI 82 and TI 83

    E-Print Network [OSTI]

    Torres, Rodolfo

    Data regression using the TI's calculators TI 82 and TI 83 TI 85 TI 86 Doing data regression in the TI-82 or TI-83 Entering the data Press to get the statistics menu. Select and press .Edit Enter the x-data in L1 and the y-data in L2. Doing the regression Press to get the statistics menu. Select and select

  4. Ann bay lodyans 13 / Se Bryant Freeman ("Tonton Liben") ki pare ti liv sa a

    E-Print Network [OSTI]

    Freeman, Bryant C.

    2000-01-01

    , li pa kite anyen deye. Mouche ale ak ni jwet zo li, ni kat li, ni boutey tafya, menm ti bout tanbou a li pa bliye mete. Konsa, kon mouche rive anwo a, li tabli yon jwet zo ak yon jwet kat, ansanm ak yon konmes kleren. Sa fe, pyes travay pa ka fet... sa a se yon danje piblik. Fok yo jwenn bout li. Depi Telisfo vini an, lanfe a vin tounen yon peyi pleziyis. Abitan yo pwofite fe parese. Men tou, Telisfo pa kite yo gen anyen, menm bout sigaret pa ka rete. Sa ki pi red, se chak jou yon moun...

  5. Melt Processed Single Phase Hollandite Waste Forms For Nuclear Waste Immobilization: Ba{sub 1.0}Cs{sub 0.3}A{sub 2.3}Ti{sub 5.7}O{sub 16}; A = Cr, Fe, Al

    SciTech Connect (OSTI)

    Brinkman, Kyle [Savannah River National Laboratory, Aiken, SC 29808 (United States); Marra, James [Savannah River National Laboratory, Aiken, SC 29808 (United States); Amoroso, Jake [Savannah River National Laboratory, Aiken, SC 29808 (United States); Conradson, Steven D. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Tang, Ming [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2013-09-23

    Cs is one of the more problematic fission product radionuclides to immobilize due to its high volatility at elevated temperatures, ability to form water soluble compounds, and its mobility in many host materials. The hollandite structure is a promising crystalline host for Cs immobilization and has been traditionally fabricated by solid state sintering methods. This study presents the structure and performance of Ba{sub 1.0}Cs{sub 0.3}A{sub 2.3}Ti{sub 5.7}O{sub 16}; A = Cr, Fe, Al hollandite fabricated by melt processing. Melt processing is considered advantageous given that melters are currently in use for High Level Waste (HLW) vitrification in several countries. This work details the impact of Cr additions that were demonstrated to i) promote the formation of a Cs containing hollandite phase and ii) maintain the stability of the hollandite phase in reducing conditions anticipated for multiphase waste form processing.

  6. Domain matched epitaxial growth of (111) Ba{sub 0.5}Sr{sub 0.5}TiO{sub 3} thin films on (0001) Al{sub 2}O{sub 3} with ZnO buffer layer

    SciTech Connect (OSTI)

    Krishnaprasad, P. S. E-mail: mkj@cusat.ac.in; Jayaraj, M. K. E-mail: mkj@cusat.ac.in; Antony, Aldrin; Rojas, Fredy

    2015-03-28

    Epitaxial (111) Ba{sub 0.5}Sr{sub 0.5}TiO{sub 3} (BST) thin films have been grown by pulsed laser deposition on (0001) Al{sub 2}O{sub 3} substrate with ZnO as buffer layer. The x-ray ?-2?, ?-scan and reciprocal space mapping indicate epitaxial nature of BST thin films. The domain matched epitaxial growth of BST thin films over ZnO buffer layer was confirmed using Fourier filtered high resolution transmission electron microscope images of the film-buffer interface. The incorporation of ZnO buffer layer effectively suppressed the lattice mismatch and promoted domain matched epitaxial growth of BST thin films. Coplanar inter digital capacitors fabricated on epitaxial (111) BST thin films show significantly improved tunable performance over polycrystalline thin films.

  7. Enhancing solar photocatalytic detoxification by adsorption of porphyrins onto TiO sub 2

    SciTech Connect (OSTI)

    Majumder, S.A.; Ondrias, M.R. . Dept. of Chemistry); Prairie, M.R.; Shelnutt, J.A. )

    1991-01-01

    Titanium dioxide (TiO{sub 2}) is a known photocatalyst for solar detoxification of water containing organic contaminants including PCB's and dioxins. Unfortunately, the UV light used by the photocatalyst only comprises about 4% of the strong spectrum. Metalloporphyrins strongly absorb in the visible and near infrared region. Using visible light, we have investigated Ni(II) uroporphyrin (NiUroP), Sn(IV)Cl{sub 2} uroporphyrin (SnUroP) and Sn(IV)Cl{sub 2} tetrakis(p-carboxyphenyl) porphyrin (SnTCPP) as possible enhancers of destruction of a model organic compound, salicylic acid (SA), by means of photosensitization of colloidal TiO{sub 2} particles. All three porphyrins are found to adsorb reversibly onto the colloidal TiO{sub 2} upon variation of pH. Adsorption of porphyrins results in the increased colloidal stability of fine TiO{sub 2} particles in the pH range 5--8. While NiUroP on TiO{sub 2} does not show any enhancement of photodestruction, the adsorption of SnUroP increases the destruction rate compared to that of the bare TiO{sub 2} surface. The effect of ambient oxygen on the observed photolability of the Sn porphyrins and enhancement of photodestruction of SA was also investigated. SnTCPP does not photodecompose upon illumination either in the presence or absence of TiO{sub 2}, but neither does it bind to the photocatalyst at pH 6. At pH 4.5 it adsorbs onto TiO{sub 2} but it also photodecompose at this pH. We are attempting to stabilize the adsorbed porphyrins by adding suitable peripheral substituents onto the porphyrin macrocycle. 27 refs., 6 figs.

  8. High Nb, Ta, and Al creep- and oxidation-resistant austenitic stainless steel

    DOE Patents [OSTI]

    Brady, Michael P (Oak Ridge, TN) [Oak Ridge, TN; Santella, Michael L (Knoxville, TN) [Knoxville, TN; Yamamoto, Yukinori (Oak Ridge, TN) [Oak Ridge, TN; Liu, Chain-tsuan (Oak Ridge, TN) [Oak Ridge, TN

    2010-07-13

    An austenitic stainless steel HTUPS alloy includes, in weight percent: 15 to 30 Ni; 10 to 15 Cr; 2 to 5 Al; 0.6 to 5 total of at least one of Nb and Ta; no more than 0.3 of combined Ti+V; up to 3 Mo; up to 3 Co; up to 1 W; up to 0.5 Cu; up to 4 Mn; up to 1 Si; 0.05 to 0.15 C; up to 0.15 B; up to 0.05 P; up to 1 total of at least one of Y, La, Ce, Hf, and Zr; less than 0.05 N; and base Fe, wherein the weight percent Fe is greater than the weight percent Ni wherein said alloy forms an external continuous scale comprising alumina, nanometer scale sized particles distributed throughout the microstructure, said particles comprising at least one composition selected from the group consisting of NbC and TaC, and a stable essentially single phase fcc austenitic matrix microstructure, said austenitic matrix being essentially delta-ferrite-free and essentially BCC-phase-free.

  9. Experimental determination of band offsets of NiO-based thin film heterojunctions

    SciTech Connect (OSTI)

    Kawade, Daisuke; Sugiyama, Mutsumi, E-mail: mutsumi@rs.noda.tus.ac.jp [Faculty of Science and Technology/Research Institute for Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda 278-8510 (Japan); Chichibu, Shigefusa F. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba, Sendai 980–8577 (Japan)

    2014-10-28

    The energy band diagrams of NiO-based solar cell structures that use various n-type oxide semiconductors such as ZnO, Mg{sub 0.3}Zn{sub 0.7}O, Zn{sub 0.5}Sn{sub 0.5}O, In{sub 2}O{sub 3}:Sn (ITO), SnO{sub 2}, and TiO{sub 2} were evaluated by photoelectron yield spectroscopy. The valence band discontinuities were estimated to be 1.6?eV for ZnO/NiO and Mg{sub 0.3}Zn{sub 0.7}O/NiO, 1.7?eV for Zn{sub 0.5}Sn{sub 0.5}O/NiO and ITO/NiO, and 1.8?eV for SnO{sub 2}/NiO and TiO{sub 2}/NiO heterojunctions. By using the valence band discontinuity values and corresponding energy bandgaps of the layers, energy band diagrams were developed. Judging from the band diagram, an appropriate solar cell consisting of p-type NiO and n-type ZnO layers was deposited on ITO, and a slight but noticeable photovoltaic effect was obtained with an open circuit voltage (V{sub oc}) of 0.96?V, short circuit current density (J{sub sc}) of 2.2??A/cm{sup 2}, and fill factor of 0.44.

  10. On characterisation of wire-arc-plasma-sprayed Ni on alumina substrate

    SciTech Connect (OSTI)

    Laik, A.; Chakravarthy, D.P.; Kale, G.B. . E-mail: gbkale@apsara.barc.ernet.in

    2005-08-15

    A study was carried out on metal-ceramic bonding produced by the technique of wire-arc-plasma spraying of Ni on Al{sub 2}O{sub 3} substrate. The Ni layer and the Ni/Al{sub 2}O{sub 3} interface were characterised using optical and electro-optic techniques. The plasma-deposited Ni layer shows a uniform lamellar microstructure throughout the cross-section. The metal-ceramic interface was found to be well bonded with no pores, flaws or cracks in the as-sprayed condition. The optical metallography and concentration profiles established with the help of an electron probe microanalyser confirmed the absence of any intermediate phase at the interface. An annealing treatment at 1273 K for 24 h on the plasma-coated samples did not result in formation of any intermetallic compound or spinel at the Ni/Al{sub 2}O{sub 3} interface. This indicates that the oxygen picked up by Ni during the spraying operation is less than the threshold value required to form the spinel NiAl{sub 2}O{sub 4}.

  11. Amorphous Al-transition Metal Alloys as Anode Material for Lithium Ion Battery

    E-Print Network [OSTI]

    Wang, C.Y.

    Al based alloy powders (Al??Ni?Y?Co?Fe?) are produced by spray atomization method. High energy ball milling is done to modify the surface topology and particle size for better electrochemical performance. X ray diffraction ...

  12. (001) Oriented piezoelectric films prepared by chemical solution deposition on Ni foils

    SciTech Connect (OSTI)

    Yeo, Hong Goo, E-mail: hxy162@psu.edu; Trolier-McKinstry, Susan [Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States)

    2014-07-07

    Flexible metal foil substrates are useful in some microelectromechanical systems applications including wearable piezoelectric sensors or energy harvesters based on Pb(Zr,Ti)O? (PZT) thin films. Full utilization of the potential of piezoelectrics on metal foils requires control of the film crystallographic texture. In this study, (001) oriented PZT thin films were grown by chemical solution deposition (CSD) on Ni foil and Si substrates. Ni foils were passivated using HfO? grown by atomic layer deposition in order to suppress substrate oxidation during subsequent thermal treatment. To obtain the desired orientation of PZT film, strongly (100) oriented LaNiO? films were integrated by CSD on the HfO? coated substrates. A high level of (001) LaNiO? and PZT film orientation were confirmed by X-ray diffraction patterns. Before poling, the low field dielectric permittivity and loss tangents of (001) oriented PZT films on Ni are near 780 and 0.04 at 1 kHz; the permittivity drops significantly on poling due to in-plane to out-of-plane domain switching. (001) oriented PZT film on Ni displayed a well-saturated hysteresis loop with a large remanent polarization ~36 ?C/cm², while (100) oriented PZT on Si showed slanted P-E hysteresis loops with much lower remanent polarizations. The |e{sub 31,f}| piezoelectric coefficient was around 10.6 C/m² for hot-poled (001) oriented PZT film on Ni.

  13. Physica B 304 (2001) 186192 Optical properties of TiNi, TiCo and TiFe thin films

    E-Print Network [OSTI]

    Kim, Jai Sam

    2001-01-01

    at around 2.6 eV separates these peaks. The structures of the optical conductivity spectra of 3d metal; Electronic structure; Alloys 1. Introduction The optical conductivity is a very important characteristic of a material, which can be calcu- lated if its electronic structure is known. The experimental investigations

  14. Effect of Substrate Configuration on the Grain Structure and Morphology of Electrodeposited Ni for Prototyping LIGA

    SciTech Connect (OSTI)

    Nacy Y. C. Yang

    2002-07-01

    Synchrotron X-ray lithographic molding of PMMA-Ti/Cu/Ti substrates has been developed and used in the electrodeposition of Ni microparts for prototype LIGA development at SNL, CA. Alternative molding processes that minimize x-ray beam line use and reduce processing time are of interest for the rapid fabrication of large quantities of microparts. The objective of this investigation is to examine, archive, and compare the grain structure and morphology of deposits produced from four different molding technologies currently under development. We conclude that deposit microstructure and uniformity are greatly influenced by substrate material and design configuration. The findings are summarized.

  15. Phosphorus content effect on the magnetoelectric properties of the NiP(Ni)/PZT/NiP(Ni) cylindrical layered composites

    E-Print Network [OSTI]

    Volinsky, Alex A.

    were polarized along the radial direction after electroplating a thin Ni layer on its inside and outside surfaces. The samples were pretreated with supersonic cleaning prior to Ni electroplating composite is shown else- where [13]. The final thickness of the inside and the outside coatings

  16. Role of polaron hopping in leakage current behavior of a SrTiO3 ...

    E-Print Network [OSTI]

    2014-03-14

    Dec 10, 2013 ... Meyer et al. suggested pinning of compensating electrons by the work function of the electrodes on both sides of. Ba0.3Sr0.7TiO3 thin film but ...

  17. Bimetallic Ni-Rh catalysts with low amounts of Rh for the steam and autothermal reforming of n-butane for fuel-cell applications.

    SciTech Connect (OSTI)

    Ferrandon, M.; Kropf, A. J.; Krause, T.; Chemical Sciences and Engineering Division

    2010-05-15

    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.

  18. ALD Produced B{sub 2}O{sub 3}, Al{sub 2}O{sub 3} and TiO{sub 2} Coatings on Gd{sub 2}O{sub 3} Burnable Poison Nanoparticles and Carbonaceous TRISO Coating Layers

    SciTech Connect (OSTI)

    Weimer, Alan

    2012-11-26

    This project will demonstrate the feasibility of using atomic layer deposition (ALD) to apply ultrathin neutron-absorbing, corrosion-resistant layers consisting of ceramics, metals, or combinations thereof, on particles for enhanced nuclear fuel pellets. Current pellet coating technology utilizes chemical vapor deposition (CVD) in a fluidized bed reactor to deposit thick, porous layers of C (or PyC) and SiC. These graphitic/carbide materials degrade over time owing to fission product bombardment, active oxidation, thermal management issues, and long-term irradiation effects. ALD can be used to deposit potential ceramic barrier materials of interest, including ZrO{sub 2}, Y{sub 2}O{sub 3}:ZrO{sub 2} (YSZ), Al{sub 2}O{sub 3}, and TiO{sub 2}, or neutron-absorbing materials, namely B (in BN or B{sub 2}O{sub 3}) and Gd (in Gd{sub 2}O{sub 3}). This project consists of a two-pronged approach to integrate ALD into the next-generation nuclear plant (NGNP) fuel pellet manufacturing process:

  19. Anode-supported thin-film fuel cells operated in a single chamber configuration 2T-I-12

    E-Print Network [OSTI]

    Haile, Sossina M.

    on the anode, producing a complex response in fuel cell power output. Under optimized gas compositions and flowAnode-supported thin-film fuel cells operated in a single chamber configuration 2T-I-12 Zongping of anode-supported, thin-film, single chamber fuel cells (SCFCs) have been investigated. Cells, in which Ni

  20. CH{sub 4}-CO{sub 2} reforming over Ni-substituted barium hexaaluminate catalysts

    SciTech Connect (OSTI)

    Gardner, Todd H. [U.S. DOE; Spivey, James J. [ORISE; Kugler, Edwin L.; Pakhare, Devendra

    2013-03-30

    A series of Ni-substituted barium hexaaluminate catalysts, Ba{sub 0.75}Ni{sub y}Al{sub 12?y}O{sub 19??} (y = 0.4, 0.6 and 1.0), were tested for CO{sub 2} reforming of CH{sub 4} at temperatures between 200 and 900 °C. Temperature programmed surface reaction results show that the reaction lights-off in a temperature range between 448 and 503 °C with a consistent decrease in light-off temperature with increasing Ni substitution. Isothermal runs performed at 900 °C show near equilibrium conversion and stable product concentrations for 18 h on all catalysts. Temperature programmed oxidation of the used catalysts show that the amount of carbon deposited on the catalyst increases with Ni substitution. High resolution XRD of the used Ba{sub 0.75}Ni{sub 0.4}Al{sub 11.6}O{sub 19??} catalyst shows a statistically significant contraction of the unit cell which is the result of NiO reduction from the lattice. XRD of the used catalyst also confirms the presence of graphitic carbon. XPS and ICP measurements of the as prepared catalysts show that lower levels of Ni substitution result in an increasing proportion of Ba at the surface.

  1. Nac onal~na akadem nauk Ukra ni KONDENSOVANIH

    E-Print Network [OSTI]

    tral~nih atom v operator energ h vza mod vz ti u vigl d mul~tipol~nogo r du 1], to v me ah kvantovo-Oppenge mera voni potenc al~- no energ dl centr v mas atom v qi efektivno m atomno vza mod . Zastosovu qi danu prit gann energ proporc na do R 6 (R - v dstan~ m atomami). kwo atomi toto n perebuva t~ v stanah z r

  2. Role of Benzyl Alcohol in Controlling the Growth of TiO2 on Carbon Nanotubes David J. Cooke,*,

    E-Print Network [OSTI]

    Elliott, James

    Role of Benzyl Alcohol in Controlling the Growth of TiO2 on Carbon Nanotubes David J. Cooke) in the morphological control of the growth of TiO2 on carbon nanotubes (CNTs) by the consideration of two model systems of thin-film TiO2.14,15 Kongkanand et al. reported that combining single-wall carbon nanotubes (SWCNTs

  3. Influence of nuclear structure on sub-barrier hindrance in Ni+Ni fusion

    E-Print Network [OSTI]

    C. L. Jiang; K. E. Rehm; R. V. F. Janssens; H. Esbensen; I. Ahmad; B. B. Back; P. Collon; C. N. Davids; J. P. Greene; D. J. Henderson; G. Mukherjee; R. C. Pardo; M. Paul; T. O. Pennington; D. Seweryniak; S. Sinha; Z. Zhou

    2004-02-25

    Fusion-evaporation cross sections for $^{64}$Ni+$^{64}$Ni have been measured down to the 10 nb level. For fusion between two open-shell nuclei, this is the first observation of a maximum in the $S$-factor, which signals a strong sub-barrier hindrance. A comparison with the $^{58}$Ni+$^{58}$Ni, $^{58}$Ni+$^{60}$Ni, and $^{58}$Ni+$^{64}$Ni systems indicates a strong dependence of the energy where the hindrance occurs on the stiffness of the interacting nuclei.

  4. Synthesis and Oxidation Behavior of Platinum-Enriched ?+?' Bond Coatings on Ni-Based Superalloys

    SciTech Connect (OSTI)

    Zhang, Ying [Tennessee Technological University; Ballard, D A [Tennessee Technological University; Stacy, J P [Tennessee Technological University; Pint, Bruce A [ORNL; Haynes, James A [ORNL

    2006-01-01

    Simple Pt-enriched {gamma}+{gamma}{prime} coatings were synthesized on Rene 142 and Rene N5 Ni-based superalloys by electroplating a thin layer of Pt followed by a diffusion treatment at 1150-1175 C. The Al content in the resulting {gamma}+{gamma}{prime} coating was in the range of 16-19 at.% on superalloys with 13-14 at.% Al. After oxidation testing, alumina scale adherence to these {gamma}+{gamma}{prime} coatings was not as uniform as to the {beta}-(Ni,Pt)Al coatings on the same superalloy substrates. To better understand the effect of Al, Pt and Hf concentrations on coating oxidation resistance, a number of Ni-Pt-Al cast alloys with {gamma}+{gamma}{prime} or {beta} phase were cyclically oxidized at 1100 C. The Hf-containing {gamma}+{gamma}{prime} alloys with 22 at.% Al and 10-30 at.% Pt exhibited similar oxidation resistance to the {beta} alloys with 50 at.% Al. An initial effort was made to increase the Al content in the Pt-enriched {gamma}+{gamma}{prime} coatings by introducing a short-term aluminizing process via chemical vapor deposition or pack cementation. However, too much Al was deposited, leading to the formation of {beta} or martensitic phase on the coating surface.

  5. Interface and Size Effects on TiN-based Nanostructured Thin Films 

    E-Print Network [OSTI]

    Kim, Ickchan

    2012-07-16

    dependent and the layer thickness leading to the highest radiation tolerance was around 10 nm. In addition, the embedded epitaxial cubic AlN with cladding TiN nanolayers showed higher effective thermal conductivity than that of AlN single layer as well...

  6. Sample & Assay Technologies Ni-NTA Superflow

    E-Print Network [OSTI]

    Lebendiker, Mario

    March 2007 Sample & Assay Technologies Ni-NTA Superflow Cartridge Handbook For manual or FPLCTM purification of His-tagged proteins #12;2 Ni-NTA Superflow Cartridge Handbook 03/2007 Trademarks: QIAGEN, are not to be considered unprotected by law. © 2007 QIAGEN, all rights reserved. #12;Ni-NTA Superflow Cartridge Handbook 03

  7. Introduction: Bencubbin-like meteorites (CB) are metal-rich chondritic breccias containing about 60 vol% metallic (Fe,Ni) [1]. Unlike the CBa (Becubbin, Weatherford,

    E-Print Network [OSTI]

    vol% metallic (Fe,Ni) [1]. Unlike the CBa (Becubbin, Weatherford, Gujba) subgroup, the CBb (HH 237 al. [4] found that the Ir/Fe, Pd/Fe and Ni/Fe ratios in unzoned metal grains in the CBa chondrites that the components of CBa and CBb chondrites formed in a giant impact: SO chondrules and unzoned metal in Gujba

  8. Correlating Extent of Pt–Ni Bond Formation with Low-temperature Hydrogenation of Benzene and 1,3-butadiene over Supported Pt/Ni Bimetallic Catalysts

    SciTech Connect (OSTI)

    Lonergan, W.; Vlachos, D; Chen, J

    2010-01-01

    Low-temperature hydrogenation of benzene and 1,3-butadiene on supported Pt/Ni catalysts have been used as probe reactions to correlate hydrogenation activity with the extent of Pt-Ni bimetallic bond formation. Pt/Ni bimetallic and Pt and Ni monometallic catalysts were supported on {gamma}-Al{sub 2}O{sub 3} using incipient wetness impregnation. Two sets of bimetallic catalysts were synthesized: one set to study the effect of metal atomic ratio and the other to study the effect of impregnation sequence. Fourier transform infrared spectroscopy (FTIR) CO adsorption studies were performed to characterize the surface composition of the bimetallic nanoparticles, and transmission electron microscopy (TEM) was utilized to characterize the particle size distribution. Batch reactor studies with FTIR demonstrated that all bimetallic catalysts outperformed monometallic catalysts for both benzene and 1,3-butadiene hydrogenation. Within the two sets of bimetallic catalysts, it was found that catalysts with a smaller Pt:Ni ratio possessed higher hydrogenation activity and that catalysts synthesized using co-impregnation had greater activity than sequentially impregnated catalysts. Extended X-ray absorption fine structure (EXAFS) measurements were performed in order to verify the extent of Pt-Ni bimetallic bond formation, which was found to correlate with the hydrogenation activity.

  9. ALS Visitors

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.TheoryTuesday, August 10, 20102016 NewsUsers' Executive Committee ALS Users'ALS

  10. Monopole Strength in Ni-58 

    E-Print Network [OSTI]

    Youngblood, David H.; Lui, YW.

    1991-01-01

    Differential cross-section data from 0-degrees to 8-degrees for inelastic scattering of 129 MeV alpha particles exciting Ni-58 in the region of 14-22 MeV have been analyzed to explore the existence of monopole strength at approximately E(x) = 17 Me...

  11. Microstructural studies on cast Zr[sub 3]Al-3wt%Nb

    SciTech Connect (OSTI)

    Tewari, R.; Dey, G.K.; Mukhopadhyay, P.; Banerjee, S. . Metallurgy Div.)

    1994-05-01

    In the binary Zr-Al system, Zr[sub 3]Al is the intermetallic phase richest in zirconium. In view of its low absorption cross section for thermal neutrons and its good strength and corrosion resistance, Zr[sub 3]Al may have possible applications as a structural material in thermal reactors. This phase has the ordered cubic L1[sub 2] structure and forms through the peritectoid reaction: [beta]-Zr + Zr[sub 2]Al[minus] > Zr[sub 3]Al, the reaction temperature being 1,292 K. Structurally Zr[sub 3]Al is quite similar to the [alpha][sub 2] or the Ti[sub 3]Al phase (ordered hexagonal DO[sub 19] structure) in the Ti-Al system, the two structures differing only in the stacking sequence of the close packed atomic layers. But for its inherent brittleness, Ti[sub 3]Al is a promising structural material for aerospace applications. It has, however, been demonstrated that niobium additions can reduce the brittleness of this phase. Studies on the Ti[sub 3]Al-Nb system have also shown that niobium stabilizes the high temperature [beta] phase (bcc structure) which, on cooling, can decompose through various phase reactions, generating some interesting microstructures. Similar studies on the Zr[sub 3]Al-Nb system have not been reported yet. The present paper describes some microstructural observations made on a cast Zr[sub 3]Al-3wt%Nb alloy.

  12. Engineering Al-based Thin Film Materials for Power Devices and Energy Storage Applications

    E-Print Network [OSTI]

    Perng, Ya-Chuan

    2012-01-01

    and J. P. Chang, “Atomic layer deposition of Pb(Zr, Ti)O xfilms deposited by atomic layer deposition on 4H-SiC,” Appl.AlN Thin Films by Atomic Layer Deposition on Wide Bandgap

  13. AL. I

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield Municipal Gas &SCE-SessionsSouth DakotaRobbins and Myers Co -VANaval Ordnance,:n5.5.8GE 1A L L'-AL.

  14. ALS Spectrum

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve4AJ01) (See Energy Level79AJ01)19^ U N I TALSALSSpectroscopyALS

  15. ALS Visitors

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.TheoryTuesday, August 10, 20102016 NewsUsers' Executive Committee ALS Users'ALSQuick

  16. ALS Visitors

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.TheoryTuesday, August 10, 20102016 NewsUsers' Executive Committee ALS

  17. Industry @ ALS

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory ofDid you notHeat Pumps Heat Pumpsfacility doe logoInIndustry @ ALS

  18. Reviw Al

    Gasoline and Diesel Fuel Update (EIA)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustments (Billion Cubic Feet) Wyoming963 1.969 1.979 1.988 1.996 2.003 1990-2016 East CoastReviw Al now ..

  19. Experimental determination and thermodynamic modeling of the Ni-Re binary system

    SciTech Connect (OSTI)

    Yaqoob, Khurram [Chimie Metallurgique des Terres Rares (CMTR), Institut de Chimie et des Materiaux Paris-Est (ICMPE), 2-8 rue Henri Dunant, 94320 Thiais Cedex (France)] [Chimie Metallurgique des Terres Rares (CMTR), Institut de Chimie et des Materiaux Paris-Est (ICMPE), 2-8 rue Henri Dunant, 94320 Thiais Cedex (France); Joubert, Jean-Marc, E-mail: jean-marc.joubert@icmpe.cnrs.fr [Chimie Metallurgique des Terres Rares (CMTR), Institut de Chimie et des Materiaux Paris-Est (ICMPE), 2-8 rue Henri Dunant, 94320 Thiais Cedex (France)] [Chimie Metallurgique des Terres Rares (CMTR), Institut de Chimie et des Materiaux Paris-Est (ICMPE), 2-8 rue Henri Dunant, 94320 Thiais Cedex (France)

    2012-12-15

    The phase diagram of the Ni-Re binary system has been partially reinvestigated by chemical, structural and thermal characterization of the arc melted alloys. The experimental results obtained during the present investigation were combined with the literature data and a new phase diagram of the Ni-Re binary system is proposed. In comparison with the Ni-Re phase diagram proposed by Nash et al. in 1985 [1], significant differences in the homogeneity domains, freezing ranges and peritectic reaction temperature were evidenced. On the other hand, thermodynamic modeling of the studied system by using the new experimental information has also been carried out with the help of the CALPHAD method. The calculated Ni-Re phase diagram showed a good agreement with the selected experimental information. - Graphical abstract: Ni-Re phase diagram according to the present study. Highlights: Black-Right-Pointing-Pointer Re-investigation of the Ni-Re phase diagram. Black-Right-Pointing-Pointer Extended phase field of the hcp phase. Black-Right-Pointing-Pointer Different freezing ranges and peritectic reaction temperature. Black-Right-Pointing-Pointer Thermodynamic modeling of the studied system by using the CALPHAD method.

  20. Present status of the KADoNiS database

    E-Print Network [OSTI]

    I. Dillmann; R. Plag; M. Heil; F. Käppeler; T. Rauscher

    2008-06-12

    The "Karlsruhe Astrophysical Database of Nucleosynthesis in Stars" (KADoNiS) project is an online database for experimental cross sections relevant to the $s$ process and $p$ process. It is available under \\http://nuclear-astrophysics.fzk.de/kadonis and consists of two parts. Part 1 is an updated sequel to the well-known Bao et al. compilations from 1987 and 2000, which is online since April 2005. An extension of this $s$-process database to $(n,p)$ and $(n,\\alpha)$ cross sections at $kT$= 30 keV, as in the first version of the Bao compilation, is planned. The second part of KADoNiS is a $p$-process library, which includes all available experimental data from $(p,\\gamma)$, $(p,n)$, $(\\alpha,\\gamma)$, $(\\alpha,n)$, $(\\alpha,\\alpha)$, $(n,\\alpha)$ and $(\\gamma,n)$ reactions in or close to the respective Gamow window. Despite the great number of reactions required for a $p$-process reaction network, experimental data is still scarce and up to now restricted to stable targets. Given here is a short overview about the present status of the KADoNiS database.

  1. Fabrication of functionally graded TiC/Ti composites by Laser Engineered Net Shaping

    E-Print Network [OSTI]

    DuPont, John N.

    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

  2. Tailoring the surface properties of LiNi0.4Mn0.4Co0.2O? by titanium substitution for improved high voltage cycling performance

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

    Wolff-Goodrich, Silas; Xin, Huolin L.; Lin, Feng; Markus, Isaac M.; Nordlund, Dennis; Asta, Mark; Doeff, Marca M.

    2015-07-30

    The present research aims to provide insights into the behavior of LiNi0.4Mn0.4Co0.2O2 (NMC442) and LiNi0.4Mn0.4Co0.2O? (NMC442-Ti02) cathode materials under galvanostatic cycling to high potentials, in the context of previous work which predicted that Ti-substituted variants should deliver higher capacities and exhibit better cycling stability than the unsubstituted compounds. It is found that NMC cathodes containing Ti show equivalent capacity fading but greater specific capacity than those without Ti in the same potential range. When repeatedly charged to the same degree of delithiation, NMC cathodes containing Ti showed better capacity retention. Soft x-ray absorption spectroscopy (XAS) spectra for Mn and Comore »indicated increased reduction in these elements for NMC cathodes without Ti, indicating that the substitution of Ti for Co acts to suppress the formation of a high impedance rock salt phase at the surface of NMC cathode particles. The results of this study validate the adoption of a facile change to existing NMC chemistries to improve cathode capacity retention under high voltage cycling conditions.« less

  3. Simultaneous determination of Ni-63 and Ni-59 in radioactive wastes by liquid scintillation spectrometry 

    E-Print Network [OSTI]

    Kim, Esther Miyeun

    1988-01-01

    SIMULTANEOUS DETERMINATION OF Ni-63 AND Ni-59 IN RADIOACTIVE WASTES BY LIQUID SCINTILLATION SPECTROMETRY A Thesis by ESTHER MIYEUN KIM Submitted to the Office of Graduate Studies of Texas AgtM University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE May 1988 Major Subject: Health Physics SIMULTANEOUS DETERMINATION OF Ni-63 AND Ni-59 IN RADIOACTIVE WASTES BY LIQUID SCINTILLATION SPECTROMETRY A Thesis by ESTHER MIYEUN KIM Approved as to style...

  4. ³Ni² Clusterbank Replacement Project | Argonne Leadership Computing...

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

    Ni Clusterbank Replacement Project Event Sponsor: Argonne Leadership Computing Facility Seminar Start Date: Oct 20 2015 - 12:00pm BuildingRoom: Building 241Room D173...

  5. Sources of stress gradients in electrodeposited Ni MEMS.

    SciTech Connect (OSTI)

    Hearne, Sean Joseph; Floro, Jerrold Anthony; Dyck, Christopher William

    2004-06-01

    The ability of future integrated metal-semiconductor micro-systems such as RF MEMS to perform highly complex functions will depend on developing freestanding metal structures that offer improved conductivity and reflectivity over polysilicon structures. For example, metal-based RF MEMS technology could replace the bulky RF system presently used in communications, navigation, and avionics systems. However, stress gradients that induce warpage of active components have prevented the implementation of this technology. Figure 1, is an interference micrograph image of a series of cantilever beams fabricated from electrodeposited Ni. The curvature in the beams was the result of stress gradients intrinsic to the electrodeposition process. To study the sources of the stress in electrodeposition of Ni we have incorporated a wafer curvature based stress sensor, the multibeam optical stress sensor, into an electrodeposition cell. We have determined that there are two regions of stress induced by electrodepositing Ni from a sulfamate-based bath (Fig 2). The stress evolution during the first region, 0-1000{angstrom}, was determined to be dependent only on the substrate material (Au vs. Cu), whereas the stress evolution during the second region, >1000{angstrom}, was highly dependent on the deposition conditions. In this region, the stress varied from +0.5 GPa to -0.5GPa, depending solely on the deposition rate. We examined four likely sources for the compressive intrinsic stress, i.e. reduction in tensile stress, and determined that only the adatom diffusion into grain boundaries model of Sheldon, et al. could account for the observed compressive stress. In the presentation, we shall discuss the compressive stress generation mechanisms considered and the ramifications of these results on fabrication of electrodeposited Ni for MEMS applications.

  6. Magnetic structure near the Co/NiO(001) interface

    E-Print Network [OSTI]

    Arenholz, Elke

    2008-01-01

    are perpendicular to the NiO moments, hence demonstrating2+ L 3,2 XA spectra and NiO domain pattern (inset). SpectraThe 100 directions of the NiO(001) plane and the orientation

  7. Characterization of the gate oxide of an AlGaN/GaN high electron mobility transistor

    E-Print Network [OSTI]

    Florida, University of

    2011; published online 21 March 2011 A subnanometer thick interfacial oxide layer present between used to characterize a Ni/AlGaN interfacial oxide layer with subnanometer thickness. The semiconducting

  8. In situ sulfiding of Ni-W hydrocracking catalysts : differentiation of different preparation procedures using EXAFS and HRTEM.

    SciTech Connect (OSTI)

    Kelly, S. D.; Yang, N.; Mickelson, G. E.; Greenlay, N.; Karapetrova, E.; Sinkler, W.; Bare, S. R.; UOP LLC; EXAFS Analysis

    2009-01-01

    The detailed structural characterization of the metal function of two fully formulated Ni-W hydrocracking catalysts was investigated by time resolved in situ X-ray absorption spectroscopy (EXAFS and XANES) at both the Ni K-edge and W L{sub 3}-edge, and by high resolution transmission electron microscopy. These two hydrocracking catalysts (designated as HCA and HCB) contained the same wt% of Ni and W, the same wt% of the other constituents ({gamma}-Al{sub 2}O{sub 3}/silico-aluminate), and were calcined at the same temperature, but were prepared by different methods in order to highlight the sensitivity of the characterization techniques to the structural differences. The morphology of the WS{sub 2} particles in the sulfided catalyst is substantially different between the two catalysts: in the HCA catalyst there are many more particles with multiple WS{sub 2} layers whereas in HCB there are more single layers. The average diameter of the WS{sub 2} plates is similar in both. The catalysts show a difference in the amount of W sulfidation after the 410 C sulfidation treatment in 10% H{sub 2}S/H{sub 2}. The W of HCA catalyst was completely sulfided whereas 16% W of HCB catalyst was unsulfided. Similarly there is a difference in the amount of sulfided Ni: 16% Ni in HCA and 60% Ni in HCB remain unsulfided. In the sulfided form of both catalysts the Ni exists in three different morphologies: oxidized Ni (six-fold coordinate as a nickel aluminate), nanoparticulate Ni{sub 3}S{sub 2}, and Ni decorating the edge sites of the WS{sub 2}. In both the Ni{sub 3}S{sub 2}, and Ni decorating the edge sites of the WS{sub 2}, the Ni is in a tetrahedral coordination with sulfur. In both catalysts the sulfidation of the Ni and W occurs essentially simultaneously over most of the temperature range and the sulfidation of the W proceeds through the same tungsten oxysulfide in both samples. The characterization methodology presented here is a powerful one for elucidating the structural differences of complex heterogeneous catalysts.

  9. Giant Quadrupole-Resonance in Ni Isotopes 

    E-Print Network [OSTI]

    Youngblood, David H.; Lui, YW; Garg, U.; Peterson, R. J.

    1992-01-01

    VOLUME 45, NUMBER 5 MAY 1992 Giant quadrupole resonance in Ni isotopes D. H. Youngblood and Y.-%. Lui Texas A&M UniUersity, College Station, Texas 77843 U. Garg University of Notre Dame, South Bend, Indiana 46556 R. J. Peterson University... (%) 58+12 76+14 78+14 90+16 Cp 0.80+0.04 0.84+0.04 0.82+0. 12 1.05+0. 10 2174 YOUNGBLOOD, LUI, GARG, AND PETERSON 45 1000 100 60Ni(n, n') E = 129 MeV 1 000 100 58Ni(n, n') 10 10 100 z' 1000 64Ni(n, n') 1OO~y 64 Ni 100 10 I s & & I...

  10. They Came From the Deep in the Supernova: The Origin of TiC and Metal Subgrains in Presolar Graphite Grains

    E-Print Network [OSTI]

    Katharina Lodders

    2006-06-27

    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.

  11. Electrostatic carrier doping of GdTiO3/SrTiO3 interfaces

    E-Print Network [OSTI]

    2011-01-01

    of GdTiO 3 /SrTiO 3 interfaces Pouya Moetakef, 1 Tyler A.each GdTiO 3 /SrTiO 3 interface. The sheet carrier densitieselectron gas bound to the interface. These carrier densities

  12. Micro Actuators Electrostatic actuator

    E-Print Network [OSTI]

    Leu, Tzong-Shyng "Jeremy"

    is superior to the alloy CuZnAl. ·Most of SMA materials used in micro devices are TiNi (Nitinol). (IV) Work

  13. Oxidation-resistant, solution-processed plasmonic Ni nanochain-SiO{sub x} (x?

    SciTech Connect (OSTI)

    Yu, Xiaobai; Wang, Xiaoxin; Liu, Jifeng; Zhang, Qinglin; Li, Juchuan

    2014-08-21

    Metal oxidation at high temperatures has long been a challenge in cermet solar thermal absorbers, which impedes the development of atmospherically stable, high-temperature, high-performance concentrated solar power (CSP) systems. In this work, we demonstrate solution-processed Ni nanochain-SiO{sub x} (x?Ni nanochain-SiO{sub 2} selective solar thermal absorbers that exhibit a strong anti-oxidation behavior up to 600?°C in air. The thermal stability is far superior to previously reported Ni nanoparticle-Al{sub 2}O{sub 3} selective solar thermal absorbers, which readily oxidize at 450?°C. The SiO{sub x} (x?Ni/SiO{sub x} interface to passivate the surface of Ni nanoparticles and prevent oxidation. X-ray photoelectron spectroscopy and Raman spectroscopy demonstrate that the excess Si in the SiO{sub x} (x?Ni nanostructures to form silicides at the interfaces, which further improves the anti-oxidation properties. As a result, Ni-SiO{sub x} (x?Ni-SiO{sub 2} systems. This oxidation-resistant Ni nanochain-SiO{sub x} (x?

  14. Spectromicroscopy study of interfacial Co/NiO(001)

    E-Print Network [OSTI]

    van der Laan, Gerrit

    2011-01-01

    study of interfacial Co/NiO(001) G. van der Laan, 1 N. D.the Co moments. The Ni moments in NiO prefer to be orienteda component of the moments in the NiO collinear to the Co.

  15. Layering and temperature-dependent magnetization and anisotropy of naturally produced Ni/NiO multilayers

    SciTech Connect (OSTI)

    Pappas, S. D.; Trachylis, D.; Velgakis, M. J.; Kapaklis, V.; Joensson, P. E.; Papaioannou, E. Th.; Delimitis, A.; Poulopoulos, P.; Fumagalli, P.; Politis, C.

    2012-09-01

    Ni/NiO multilayers were grown by magnetron sputtering at room temperature, with the aid of the natural oxidation procedure. That is, at the end of the deposition of each single Ni layer, air is let to flow into the vacuum chamber through a leak valve. Then, a very thin NiO layer ({approx}1.2 nm) is formed. Simulated x-ray reflectivity patterns reveal that layering is excellent for individual Ni-layer thickness larger than 2.5 nm, which is attributed to the intercalation of amorphous NiO between the polycrystalline Ni layers. The magnetization of the films, measured at temperatures 5-300 K, has almost bulk-like value, whereas the films exhibit a trend to perpendicular magnetic anisotropy (PMA) with an unusual significant positive interface anisotropy contribution, which presents a weak temperature dependence. The power-law behavior of the multilayers indicates a non-negligible contribution of higher order anisotropies in the uniaxial anisotropy. Bloch-law fittings for the temperature dependence of the magnetization in the spin-wave regime show that the magnetization in the multilayers decreases faster as a function of temperature than the one of bulk Ni. Finally, when the individual Ni-layer thickness decreases below 2 nm, the multilayer stacking vanishes, resulting in a dramatic decrease of the interface magnetic anisotropy and consequently in a decrease of the perpendicular magnetic anisotropy.

  16. High-Pressure Behavior of Perovskite: FeTiO3 Dissociation into Fe1; TiO and Fe1Ti2O5

    E-Print Network [OSTI]

    Steinle-Neumann, Gerd

    High-Pressure Behavior of Perovskite: FeTiO3 Dissociation into ðFe1À; TiÞO and Fe1þTi2ÀO5 X. Wu,1 G, Australia (Received 22 January 2009; published 7 August 2009) The stability of perovskite structure, we observe in situ the breakdown of FeTiO3 perovskite into a ðFe1À; TiÞO þ Fe1þTi2ÀO5 assemblage

  17. TiN coated aluminum electrodes for DC high voltage electron guns

    SciTech Connect (OSTI)

    Mamun, Md Abdullah A.; Elmustafa, Abdelmageed A.; Taus, Rhys; Forman, Eric; Poelker, Matthew

    2015-05-15

    Preparing electrodes made of metals like stainless steel, for use inside DC high voltage electron guns, is a labor-intensive and time-consuming process. In this paper, the authors report the exceptional high voltage performance of aluminum electrodes coated with hard titanium nitride (TiN). The aluminum electrodes were comparatively easy to manufacture and required only hours of mechanical polishing using silicon carbide paper, prior to coating with TiN by a commercial vendor. The high voltage performance of three TiN-coated aluminum electrodes, before and after gas conditioning with helium, was compared to that of bare aluminum electrodes, and electrodes manufactured from titanium alloy (Ti-6Al-4V). Following gas conditioning, each TiN-coated aluminum electrode reached ?225?kV bias voltage while generating less than 100?pA of field emission (<10?pA) using a 40?mm cathode/anode gap, corresponding to field strength of 13.7?MV/m. Smaller gaps were studied to evaluate electrode performance at higher field strength with the best performing TiN-coated aluminum electrode reaching ?22.5 MV/m with field emission less than 100?pA. These results were comparable to those obtained from our best-performing electrodes manufactured from stainless steel, titanium alloy and niobium, as reported in references cited below. The TiN coating provided a very smooth surface and with mechanical properties of the coating (hardness and modulus) superior to those of stainless steel, titanium-alloy, and niobium electrodes. These features likely contributed to the improved high voltage performance of the TiN-coated aluminum electrodes.

  18. Development of Fiber Bragg Grating Strain, Thermal, and Magnetic Sensors for Smart Structure Applications

    E-Print Network [OSTI]

    Emmons, Michael

    2012-01-01

    Y. Kurosawa et al. , “Polyimide-coated small-diameterwavelength shift in a polyimide coated FBG and the NiTiwavelength shift in a polyimide coated FBG and the NiTi

  19. Surface modification of NiTi alloy with tantalum to improve its biocompatibility and radiopacity

    E-Print Network [OSTI]

    Zheng, Yufeng

    ]. The methods to enhance the visibility under X-ray include adding a mark of noble metals and coating with gold of electroplating technique, problems such as risks of galvanic corrosion, biocompatibility and hydrogen concerning its biocompatibility [19­22]. It has been found that tantalum coatings are 100% pinhole

  20. Materials Data on TiNiGe (SG:62) by Materials Project

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Kristin Persson

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  1. Materials Data on TiInNi2 (SG:225) by Materials Project

    SciTech Connect (OSTI)

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  2. Thermomechanical Cyclic Response of TiNiPd High-Temperature Shape Memory Alloys 

    E-Print Network [OSTI]

    Atli, Kadri

    2012-10-19

    inhibiting the generation of these defects. Solid-solution strengthening through Sc microalloying and thermomechanical treatments via severe plastic deformation were the two approaches used to strengthen the HTSMA against defect generation. Thermal cycling...

  3. Difficulties in Probing Nuclear Physics: A Study of $^{44}$Ti and $^{56}$Ni

    E-Print Network [OSTI]

    Aimee Hungerford; Christopher L. Fryer; Francis X. Timmes; Patrick Young; Michael Bennett; Steven Diehl; Falk Herwig; Raphael Hirschi; Marco Pignatari; Georgios Magkotsios; Gabriel Rockefeller

    2008-11-28

    The nucleosynthetic yield from a supernova explosion depends upon a variety of effects: progenitor evolution, explosion process, details of the nuclear network, and nuclear rates. Especially in studies of integrated stellar yields, simplifications reduce these uncertainties. But nature is much more complex, and to actually study nuclear rates, we will have to understand the full, complex set of processes involved in nucleosynthesis. Here we discuss a few of these complexities and detail how the NuGrid collaboration will address them.

  4. Self-assembled Ni/TiO{sub 2} nanocomposite anodes synthesized...

    Office of Scientific and Technical Information (OSTI)

    were fabricated on three-dimensional, self-assembled nanotemplates of Tobacco mosaic virus using atomic layer deposition, exhibiting high capacities and rate capability and...

  5. Mechanical characterization of NiTi wires under pure bending G.Antherieu1

    E-Print Network [OSTI]

    Payan, Yohan

    crystallographic states: cold-worked, austenitic and martensitic. Results of a bending test on a steel wire and moment measurement during pure bending tests on steel wires (Figure 1) Bending moment/load measurements.m; the minimum reached radius of curvature was about 1.5cm. Results of a bending test on a steel wire

  6. Experimental Studies on Dynamic Vibration Absorber using Shape Memory Alloy (NiTi) Springs

    SciTech Connect (OSTI)

    Kumar, V. Raj; Kumar, M. B. Bharathi Raj; Kumar, M. Senthil [Department of Mechanical Engineering, PSG College of Technology, Coimbatore (India)

    2011-10-20

    Shape memory alloy (SMA) springs have been used as actuators in many applications although their use in the vibration control area is very recent. Since shape memory alloys differ from conventional alloy materials in many ways, the traditional design approach for springs is not completely suitable for designing SMA springs. Some vibration control concepts utilizing unique characteristics of SMA's will be presented in this paper.A dynamic vibration absorber (DVA) using shape memory alloy (SMA) actuator is developed for attenuation of vibration in a cantilever beam. The design procedure of the DVA is presented. The system consists of a cantilever beam which is considered to generate the real-time vibration using shaker. A SMA spring is used with a mass attached to its end. The stiffness of the SMA spring is dynamically varied in such a way to attenuate the vibration. Both simulation and experimentation are carried out using PID controller. The experiments were carried out by interfacing the experimental setup with a computer using LabVIEW software, Data acquisition and control are implemented using a PCI data acquisition card. Standard PID controllers have been used to control the vibration of the beam. Experimental results are used to demonstrate the effectiveness of the controllers designed and the usefulness of the proposed test platform by exciting the structure at resonance. In experimental setup, an accelerometer is used to measure the vibration which is fed to computer and correspondingly the SMA spring is actuated to change its stiffness to control the vibration. The results obtained illustrate that the developed DVA using SMA actuator is very effective in reducing structural response and have great potential to be an active vibration control medium.

  7. Materials Data on TiGaNi2 (SG:225) by Materials Project

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Kristin Persson

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  8. Materials Data on Ti4Ga3Ni2 (SG:189) by Materials Project

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Kristin Persson

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  9. Materials Data on TiGaNi (SG:189) by Materials Project

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Kristin Persson

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  10. Effect of ausforming via severe plastic deformation on shape memory behavior of NiTi 

    E-Print Network [OSTI]

    Kulkarni, Ajay V.

    2006-04-12

    Submitted to Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Approved as to style and content by: Ibrahim Karaman (Chair of Committee) Richard Griffin (Member) Amy Epps... by setting high standards. I am thankful to Prof. Richard Griffin and Prof. Amy Epps Martin, for being my committee members. I express my gratitude to Prof. Yuriy Chumlyakov for his invaluable suggestions and guidelines in my research and for sharing...

  11. Materials Data on TiNi2Sb (SG:225) by Materials Project

    SciTech Connect (OSTI)

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  12. Demonstration of high efficiency elastocaloric cooling with large Delta T using NiTi wires

    SciTech Connect (OSTI)

    Cui, J; Wu, YM; Muehlbauer, J; Hwang, YH; Radermacher, R; Fackler, S; Wuttig, M; Takeuchi, I

    2012-08-13

    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 1 1, with a directly measured Delta T of 17 degrees C. The solid-state refrigerant of EC completely eliminates the use of any GWP refrigerants including HCFCs/HFCs. (C) 2012 American Institute. of Physics. [http://dx.doiorg/10.1063/1.4746257

  13. Self-assembled Ni/TiO{sub 2} nanocomposite anodes synthesized via

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail. (Conference) |Janka,Ferrara U./INFN,Taş,Superconductors

  14. Shape-Memory Transformations of NiTi: Minimum-Energy Pathways between

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail. (Conference) |Janka,FerraraTechnologies (Conference)phase (Journal

  15. TRENDS IN {sup 44}Ti AND {sup 56}Ni FROM CORE-COLLAPSE SUPERNOVAE (Journal

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail. (Conference)Feedback SystemGimbaled X-Ray Head (JournalSciTechAUTHORS(Conference)

  16. ALS User Meeting

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

    ALS User Meeting Print web banner ALS User Meeting: October 5-7, 2015 Home Agenda Awards Exhibitors Lodging Posters Registration Transportation Workshops Contact Us User Meeting...

  17. Fig. 1. Magnetic hysteresis of NiO-doped NiF2 conversion materials

    E-Print Network [OSTI]

    Siegel, Paul H.

    member with CMRR, is leading her group to design, optimize and develop new materials for energy storage materials for higher energy lithium ion batteries (at least double the energy density of today's technologyFig. 1. Magnetic hysteresis of NiO-doped NiF2 conversion materials CMRR Newsletter Shirley Meng

  18. Antiproton Production in Ni+ni Collisions at 1.85 Gev/nucleon 

    E-Print Network [OSTI]

    LI, GQ; Ko, Che Ming.

    1994-01-01

    Antiproton production in Ni+Ni collisions at 1.85 GeV/nucleon is studied in the relativistic Vlasov-Uehling-Uhlenbeck model. The self-energies of the antiproton are determined from the nucleon self-energies by the G-parity transformation. Also...

  19. Nuclear Instruments and Methods in Physics Research A 582 (2007) 261263 Electronic structure of FeAl(1 1 0) using upgraded 6 m-TGM at CAMD

    E-Print Network [OSTI]

    2007-01-01

    .g. NiAl, CoAl, and FeAl, have attracted considerable interest due to their unique properties of intermetallic alloy surfaces is their effect on physical and chemical properties such as corrosion resistance by changing the stoichiometry of alloys. To modify and control these properties require a detailed

  20. r1(t) = (cos t)i + (sin t)i + tk, at

    E-Print Network [OSTI]

    MA 271 EXAM 1 FALL 2002 Name. 1. Find the angle between the curves at the indicated point. r1(t) = (cos t)i + (sin t)i + tk, at (1,0,0). 1-20) = (1 + t)i + tzj + tetk,. 2.

  1. A=17Li (1993TI07)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01) (Not93TI07)93TI07) (See Energy Level93TI07)93TI07)

  2. A=17Ne (1993TI07)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01) (Not93TI07)93TI07) (See93TI07)82AJ01) (See93TI07)

  3. Electron-Transport Properties of Amorphous (Zr0.64ni0.36)1-Xalx Alloys 

    E-Print Network [OSTI]

    BHATNAGAR, AK; PAN, R.; Naugle, Donald G.

    1989-01-01

    .06 ?~x=0.15 ?x=0. 1 0 x=0.20 C; 210- 1.04- OO x =0.25~ . . ::.- -? .~x=0.05 185 . 1.02-. x=0.0~ '- 160 0.1 0.2 0.3 FIG. 2. Room-temperature (300-K) resistivity p as a function of Al concentration x for amorphous (ZrQ 64NiQ 3{j), Al... coefficient 8& for amorphous (ZrQ 64NiQ 36) ) Al . 0 0.05 0.10 0.15 0.20 0.25 0.30 Tcryst (K) 679' 747" 718" 785" 764' 792' 800' T. (K) 2.54' 2.560' 2.68g 2.05' 2.33g 1.62' 1.810 pm (g/cm ) 7.25' 7.10' 6.96' 6.73' 6.53' 6...

  4. NbTiN Based SIS Multilayer Structures for SRF Applications

    SciTech Connect (OSTI)

    Valente, Anne-marie; Eremeev, Grigory; Phillips, H.; Reece, Charles; Spradlin, Joshua; Yang, Qiguang; Lukaszew, Rosa

    2013-09-01

    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.

  5. Preparation of PtNi Nanoparticles for the Electrocatalytic Oxidation of Methanol

    E-Print Network [OSTI]

    Deivaraj, T.C.

    Carbon supported PtNi nanoparticles were prepared by hydrazine reduction of Pt and Ni precursor salts under different conditions, namely by conventional heating (PtNi-1), by prolonged reaction at room temperature (PtNi-2) ...

  6. Blending Cr2O3 into a NiO-Ni electrocatalyst for sustained water splitting

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

    Gong, Ming; Zhou, Wu; Kenney, Michael James; Kapusta, Rich; Cowley, Sam; Wu, Yingpeng; Lu, Bingan; Lin, Meng -Chang; Wang, Di -Yan; Yang, Jiang; et al

    2015-08-24

    The rising H2 economy demands active and durable electrocatalysts based on low-cost, earth-abundant materials for water electrolysis/photolysis. Here we report nanoscale Ni metal cores over-coated by a Cr2O3-blended NiO layer synthesized on metallic foam substrates. The Ni@NiO/Cr2O3 triphase material exhibits superior activity and stability similar to Pt for the hydrogen-evolution reaction in basic solutions. The chemically stable Cr2O3 is crucial for preventing oxidation of the Ni core, maintaining abundant NiO/Ni interfaces as catalytically active sites in the heterostructure and thus imparting high stability to the hydrogen-evolution catalyst. The highly active and stable electrocatalyst enables an alkaline electrolyzer operating at 20more »mA cm–2 at a voltage lower than 1.5 V, lasting longer than 3 weeks without decay. Thus, the non-precious metal catalysts afford a high efficiency of about 15 % for light-driven water splitting using GaAs solar cells.« less

  7. Energy absorption in Ni-Mn-Ga/ polymer composites

    E-Print Network [OSTI]

    Feuchtwanger, Jorge

    2006-01-01

    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 ...

  8. Carbon Nanotube Growth Using Ni Catalyst in Different Layouts

    E-Print Network [OSTI]

    Nguyen, H. Q.

    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 ...

  9. Gii thiu v trng UMass Amherst l trng ni ting trong h thng i Hc Mas-

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    trng i hc vi 60% s sinh viên i hc ti các khu ký túc xá trong trng và thng thc các món n cng tin. Cng hc ca trng cng c ánh giá rt cao. Bng xp hng 5.000 chng trình tin s nm 2010 ca y Ban Nghiên Cu Quc Gia hc t thc. Tám ngành hc khác cng rt ni ting là: công ngh sinh hc ng vt, hóa k thut, hóa hc, công ngh

  10. Gorzkowski et al. 1 Changes in the Distribution of Interfaces in PMN-35 mol% PT as a Function of Time

    E-Print Network [OSTI]

    Rohrer, Gregory S.

    Gorzkowski et al. 1 Changes in the Distribution of Interfaces in PMN- 35 mol% PT as a Function-3890 Abstract The crystallographic distribution of surfaces surrounding grains in PMN- 35 mol% PT has been to solid- state growth methods demonstrated in Al2O3 11 and BaTiO3.12 Growth of PMN-35PT single crystals

  11. Enhanced electron collection in TiO{sub 2} nanoparticle-based dye-sensitized solar cells by an array of metal micropillars on a planar fluorinated tin oxide anode.

    SciTech Connect (OSTI)

    Yang, Z.; Xu, T.; Gao, S.; Welp, U.; Kwok, W.-K.; Materials Science Division; Northern Illinois Univ.

    2010-01-01

    Charge collection efficiency exhibits a strong influence on the overall efficiency of nanocrystalline dye-sensitized solar cells. It highly depends on the quality of the TiO{sub 2} nanoparticulate layer in the photoanode, and hence most efforts have been directed on the improvement and deliberate optimization of the quality the TiO{sub 2} nanocrystalline layer. In this work, we aim to reduce the electron collection distance between the place of origin in the TiO{sub 2} layer to the electron-collecting TCO anode as an alternative way to enhance the charge collection efficiency. We use an array of metal micropillars on fluorine-doped tin oxide (FTO) as the collecting anode. Under the same conditions, the Ni micropillar-on-FTO-based dye-sensitized solar cells (DSSCs) exhibit a remarkably enhanced current density, which is approximately 1.8 times greater compared with the bare FTO-based DSSCs. Electron transport was investigated using the electrochemical impedance spectroscopy technique. Our results reveal that the electron collection time in Ni micropillar-on-FTO-based DSSCs is much shorter than that of bare FTO-based DSSCs, indicating faster electron collection due to the Ni micropillars buried in TiO{sub 2} nanoparticulate layer that serve as electron transport shortcuts. As a result, the charge collection efficiency was enhanced by 15?20% with respect to that of the bare FTO-based DSSCs. Consequently, the overall energy conversion efficiency was found to increase from 2.6% in bare FTO-based DSSCs to 4.8% in Ni micropillar-on-FTO-based DSSCs for a 6 {micro}m-thick TiO{sub 2} NP film.

  12. Oxygen Adsorption on Au–Ni(111) Surface Alloys

    E-Print Network [OSTI]

    Lee, Jae-Gook

    Molecular O[subscript 2] dissociates upon interaction with a Ni(111) surface, as the spatial and energetic overlap between the Ni 3d electrons and the O[subscript 2] antibonding orbitals is quite favorable. On a Au–Ni(111) ...

  13. Ti Leggett | Argonne National Laboratory

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorking With U.S.Week DayDr.Theories (Journal Article) | SciTech20Home3Ti

  14. Giant monopole strength in Ni-58 

    E-Print Network [OSTI]

    Lui, YW; Clark, HL; Youngblood, David H.

    2000-01-01

    The strength distribution of the giant monopole resonance in Ni-58 has been measured from E-x = 10 to 35 MeV using small-angle scattering of 240-MeV alpha particles. E0 strength corresponding to 74(-12)(+22)% of the E0 EWSR was found between E-x...

  15. KADoNiS- The Karlsruhe Astrophysical Database of Nucleosynthesis in Stars

    E-Print Network [OSTI]

    I. Dillmann; M. Heil; F. Käppeler; R. Plag; T. Rauscher; F. -K. Thielemann

    2008-05-30

    The "Karlsruhe Astrophysical Database of Nucleosynthesis in Stars" (KADoNiS) project is an online database for experimental cross sections relevant to the s process and p process. It is available under http://nuclear-astrophysics.fzk.de/kadonis and consists of two parts. Part 1 is an updated sequel to the previous Bao et al. compilations from 1987 and 2000 for (n,$\\gamma$) cross sections relevant to the big bang and s-process nucleosynthesis. The second part will be an experimental p-process database, which is expected to be launched in winter 2005/06. The KADoNiS project started in April 2005, and a first partial update is online since August 2005. In this paper we present a short overview of the first update of the s-process database, as well as an overview of the status of stellar (n,$\\gamma$) cross sections of all 32 p isotopes.

  16. Effect of hydrothermal condition on the formation of multi-component oxides of Ni-based metallic glass under high temperature water near the critical point

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

    Kim, J. S.; Kim, S. Y.; Kim, D. H.; Ott, R. T.; Kim, H. G.; Lee, M. H.

    2015-07-01

    The specific feature of multi-component oxides synthesized by hydrothermal process under high temperature (633 K) and highly pressurized water (18.9 MPa) near critical point. Effects of hydrothermal processing duration times 24 hours and 72 hours, respectively, on the oxide formation of the Ni59Zr20Ti16Si2Sn3 metallic glass synthesized by powder metallurgy process were characterized by X-ray diffractometer, differential scanning calorimeter along with the particle size, morphology and crystalline phase of the oxides. The crystallization of the needle-shape NiTiO3, ZrTiO4 and ZrSnO4 ternary oxide phases observed on the surface of metallic glass at below glass transition temperature and the morphology of oxide phasesmore »changed to plate-shape around 2 ?m in diameter by the increase processing time. This hydrothermal processing in subcritical water provides accelerated dense metal oxide crystals due to the reaction medium being at higher pressure than conventional oxidation processing.« less

  17. In Situ XAS of Ni-W Hydrocracking Catalysts

    SciTech Connect (OSTI)

    Yang, N. [Argonne National Laboratory, Argonne, IL 60439 (United States); Mickelson, G. E.; Greenlay, N.; Bare, Simon R. [UOP LLC, Des Plaines, IL 60016 (United States); Kelly, S. D. [EXAFS Analysis, Bolingbrook, IL 60440 (United States)

    2007-02-02

    Ni-W based catalysts are very attractive in hydrotreating of heavy oil due to their high hydrogenation activity. In the present research, two catalyst samples, prepared by different methods, that exhibit significant differences in activity were sulfided in situ, and the local structure of the Ni and W were studied using X-ray absorption spectroscopy (XAS). The Ni XANES spectra were analyzed using a linear component fitting, and the EXAFS spectra of the WS2 platelets in the sulfided catalysts were modeled. The Ni and W are fully sulfided in the higher activity sample, and there are both unsulfided Ni ({approx}25%) and W (<10%) in the lower activity sample.

  18. X-ray Absorption Measurements on Nickel Cathode of Sodium-beta Alumina batteries: Fe-Ni-CI Chemical Associations

    SciTech Connect (OSTI)

    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.

    2014-02-01

    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.

  19. Enhanced magnetic moment and conductive behavior in NiFe{sub 2}O{sub 4} spinel ultrathin films

    SciTech Connect (OSTI)

    Lueders, Ulrike [Institut de Ciencia de Materials de Barcelona, CSIC, Campus de la UAB, 08193 Bellaterra, Catalunya (Spain); LPMC-FRE2686 CNRS-ONERA, 2 avenue Edouard Belin, 31400 Toulouse (France); Bibes, Manuel [Unite Mixte de Physique THALES/CNRS, Domaine de Corbeville, 91404 Orsay (France); Institut d'Electronique Fondamentale, Universite Paris-Sud, 91405 Orsay (France); Bobo, Jean-Francois [LPMC-FRE2686 CNRS-ONERA, 2 avenue Edouard Belin, 31400 Toulouse (France); Cantoni, Matteo; Bertacco, Riccardo [INFM and L-NESS, Dipartimento di Fisica del Politecnico di Milano, via Anzani 52, 22100 Como (Italy); Fontcuberta, Josep [Institut de Ciencia de Materials de Barcelona, CSIC, Campus de la UAB, 08193 Bellaterra, Catalunya (Spain)

    2005-04-01

    Bulk NiFe{sub 2}O{sub 4} is an insulating ferrimagnet. Here, we report on the epitaxial growth of spinel NiFe{sub 2}O{sub 4} ultrathin films onto SrTiO{sub 3} single crystals. We will show that--under appropriate growth conditions--epitaxial stabilization leads to the formation of a spinel phase with magnetic and electrical properties that radically differ from those of the bulk material: an enhanced magnetic moment (M{sub S})--about 250% larger--and a metallic character. A systematic study of the thickness dependence of M{sub S} allows us to conclude that its enhanced value is due to an anomalous distribution of the Fe and Ni cations among the A and B sites of the spinel structure resulting from the off-equilibrium growth conditions and to interface effects. The relevance of these findings for spinel- and, more generally, oxide-based heterostructures is discussed. We will argue that this novel material could be an alternative ferromagetic-metallic electrode in magnetic tunnel junctions.

  20. Microstructure and tribological performance of nanocomposite Ti-Si-C-N coatings deposited using hexamethyldisilazane precursor

    SciTech Connect (OSTI)

    Wei Ronghua; Rincon, Christopher; Langa, Edward; Yang Qi

    2010-09-15

    Thick nanocomposite Ti-Si-C-N coatings (20-30 {mu}m) were deposited on Ti-6Al-4V substrate by magnetron sputtering of Ti in a gas mixture of Ar, N{sub 2}, and hexamethyldisilazane (HMDSN) under various deposition conditions. Microstructure and composition of the coatings were studied using scanning electron microscopy, x-ray diffraction, and energy dispersive x-ray spectroscopy, while the mechanical and tribological properties of these coatings were studied using Rc indentation, and micro- and nanoindentations, solid particle erosion testing, and ball-on-disk wear testing. It has been observed that the Si concentration of these coatings is varied from 0% (TiN) to 15% (Ti-Si-C-N), while the structure of these coatings is similar to the nanocomposite Ti-Si-N coatings and consists of nanocrystalline B1 structured Ti(C,N) in an amorphous matrix of SiC{sub x}N{sub y} with the grain size of 5->100 nm, depending on the coating preparation process. These coatings exhibit excellent adhesion when subjected to Rc indentation tests. The microhardness of these coatings varies from 1200 to 3400 HV25, while the nanohardness varies from 10 to 26 GPa. Both the microhardness and nanohardness are slightly lower than those of similar coatings prepared using trimethylsilane. However, the erosion test using a microsand erosion tester at both 30 deg. and 90 deg. incident angles shows that these coatings have very high erosion resistance and up to a few hundred times of improvement has been observed. These coatings also exhibit very high resistance to sliding wear with a low coefficient of friction of about 0.2 in dry sliding. There are a few advantages of using the HMDSN precursor to prepare the Ti-Si-C-N coatings over conventional magnetron sputtered deposition of Ti-Si-N coatings including composition uniformity, precursor handling safety, and high deposition rate. The coatings can be applied to protect gas turbine compressor blades from solid particle erosion and steam turbine blades from liquid droplet erosion, as well as other mechanical components that experience severe abrasion. These coatings may also be used in areas where both high wear resistance and low friction are required.

  1. A=17C (1993TI07)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01) (Not93TI07) (Not1959AJ76)93TI07) (Not2AJ01)93TI07)

  2. A=17He (1993TI07)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01) (Not93TI07)93TI07) (See Energy Level93TI07) (Not

  3. A=17N (1993TI07)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01) (Not93TI07)93TI07) (See93TI07) (See Energy Level

  4. A=17Na (1993TI07)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01) (Not93TI07)93TI07) (See93TI07) (See6AJ04)

  5. A=17Si (1993TI07)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01) (Not93TI07)93TI07)82AJ01) (SeeSi (1993TI07) (Not

  6. A=18C (1995TI07)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01) (Not93TI07)93TI07)82AJ01)83AJ01) (Not95TI07) (See

  7. High Energy Density Na-S/NiCl2 Hybrid Battery

    SciTech Connect (OSTI)

    Lu, Xiaochuan; Lemmon, John P.; Kim, Jin Yong; Sprenkle, Vincent L.; Yang, Zhenguo

    2013-02-15

    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.

  8. Microstructures in rapidly solidified Ni-Mo alloys

    SciTech Connect (OSTI)

    Jayaraman, N.; Tewari, S.N.; Hemker, K.J.; Glasgow, T.K.

    1985-01-01

    Ni-Mo alloys of compositions ranging from pure Ni to Ni-40 at % Mo were rapidly solidified by chill block melt spinning in vacuum and were examined by optical metallography, x-ray diffraction and transmission electron microscopy. Rapid solidification resulted in an extension of molybdenum solubility in nickel from 28 to 37.5 at %. A number of different phases and microstructures were seen at different depths (solidification conditions) from the quenched surface of the melt spun ribbons.

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

    E-Print Network [OSTI]

    Li, Tiezheng

    2006-01-01

    of ductile- phase reinforcements in the fracture toughnessfracture toughness (up to 2 MPa m ) limit its potential applications and ductiletoughness at lower temperature by modifying their intrinsic fracture properties and by reinforcing intermetallics with ductile

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

    E-Print Network [OSTI]

    Li, Tiezheng

    2006-01-01

    efficiency of gas turbine engines. Table 2 Characteristicsand build advanced gas turbine engines [ 69 - 71 ] with

  11. Oxidation-resistant, solution-processed plasmonic Ni nanochain...

    Office of Scientific and Technical Information (OSTI)

    solution-processed plasmonic Ni nanochain-SiOsub x (x < 2) selective solar thermal absorbers Citation Details In-Document Search Title: Oxidation-resistant,...

  12. Fusion of radioactive $^{132}$Sn with $^{64}$Ni

    E-Print Network [OSTI]

    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

    2007-04-05

    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.

  13. Diario de Sevilla, 16 de febrero de 2005 20-F: ni alarmas ni dramatismos

    E-Print Network [OSTI]

    Bilbao Arrese, Jesús Mario

    democracia directa es obligar al elector a convertirse en decisor. Mientras que la participación política en

  14. Incorporation of trace elements in Portland cement clinker: Thresholds limits for Cu, Ni, Sn or Zn

    SciTech Connect (OSTI)

    Gineys, N.; Aouad, G.; Sorrentino, F.; Damidot, D.

    2011-11-15

    This paper aims at defining precisely, the threshold limits for several trace elements (Cu, Ni, Sn or Zn) which correspond to the maximum amount that could be incorporated into a standard clinker whilst reaching the limit of solid solution of its four major phases (C{sub 3}S, C{sub 2}S, C{sub 3}A and C{sub 4}AF). These threshold limits were investigated through laboratory synthesised clinkers that were mainly studied by X-ray Diffraction and Scanning Electron Microscopy. The reference clinker was close to a typical Portland clinker (65% C{sub 3}S, 18% C{sub 2}S, 8% C{sub 3}A and 8% C{sub 4}AF). The threshold limits for Cu, Ni, Zn and Sn are quite high with respect to the current contents in clinker and were respectively equal to 0.35, 0.5, 0.7 and 1 wt.%. It appeared that beyond the defined threshold limits, trace elements had different behaviours. Ni was associated with Mg as a magnesium nickel oxide (MgNiO{sub 2}) and Sn reacted with lime to form a calcium stannate (Ca{sub 2}SnO{sub 4}). Cu changed the crystallisation process and affected therefore the formation of C{sub 3}S. Indeed a high content of Cu in clinker led to the decomposition of C{sub 3}S into C{sub 2}S and of free lime. Zn, in turn, affected the formation of C{sub 3}A. Ca{sub 6}Zn{sub 3}Al{sub 4}O{sub 15} was formed whilst a tremendous reduction of C{sub 3}A content was identified. The reactivity of cements made with the clinkers at the threshold limits was followed by calorimetry and compressive strength measurements on cement paste. The results revealed that the doped cements were at least as reactive as the reference cement.

  15. Aluminum Stabilized NbTi Conductor Test Coil Design, Fabrication, and Test Results

    SciTech Connect (OSTI)

    Andreev, N.; Chlachidze, G.; Evbota, D.; Kashikhin, V.S.; Lamm, M.; Makarov, A.; Tartaglia, M.; Nakamoto, T.; Ogitsu, T.; Tanaka, K.; Yamamoto, A.; /KEK, Tsukuba

    2011-09-01

    A new generation of precision muon conversion experiments is planned at both Fermilab and KEK. These experiments will depend upon a complex set of solenoid magnets for the production, momentum selection and transport of a muon beam to a stopping target, and for tracking detector momentum analysis of candidate conversion electrons from the target. Baseline designs for the production and detector solenoids use NbTi cable that is heavily stabilized by an extruded high RRR aluminum jacket. A U.S.-Japan research collaboration has begun whose goal is to advance the development of optimized Al-NbTi conductors, gain experience with the technology of winding coils from this material, and test the conductor performance as modest length samples become available. For this purpose, a 'conductor test' solenoid with three coils was designed and built at Fermilab. A sample of the RIKEN Al-NbTi conductor from KEK was wound into a 'test' coil; this was sandwiched between two 'field' coils wound from doubled SSC cable, to increase the peak field on the RIKEN test coil. All three solenoid coils were epoxy impregnated, and utilized aluminum outer bandage rings to apply preload to the coils when cold. The design and fabrication details, and results of the magnet quench performance tests are presented and discussed.

  16. Enhanced photocatalytic efficiency in zirconia buffered n-NiO/p-NiO single crystalline heterostructures by nanosecond laser treatment

    SciTech Connect (OSTI)

    Molaei, R.; Bayati, M. R.; Alipour, H. M.; Nori, S.; Narayan, J.

    2013-06-21

    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.

  17. Materials Data on Er3Al3NiGe2 (SG:189) by Materials Project

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Kristin Persson

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  18. Materials Data on CeAl3Ni2 (SG:191) by Materials Project

    SciTech Connect (OSTI)

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  19. Structure and magnetic properties of Ce?(Ni/Al/Ga)??-A new phase...

    Office of Scientific and Technical Information (OSTI)

    Technial Information About OSTI Mission Organization Chart Achievements Alliances OSTI History Feedback DOE STI Program Scientific and Technical Information Program (STIP)...

  20. Materials Data on BaAl9Ni2 (SG:191) by Materials Project

    SciTech Connect (OSTI)

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  1. Phase transformations during rapid heating of Al/Ni multilayer foils Jonathan C. Trenkle,1

    E-Print Network [OSTI]

    Gruner, Sol M.

    -known thermite reaction is one example. Recently, self-propagating formation reactions have been studied

  2. Er-Mssbauer investigation of ErNiAl4 D.H. Ryan1, a

    E-Print Network [OSTI]

    Ryan, Dominic

    to the highest CF levels, further INS measurements (with Einc 40 meV) will be undertaken at CNBC Chalk River

  3. Materials Data on DyAl4Ni (SG:63) by Materials Project

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Kristin Persson

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  4. Materials Data on CeAl4Ni (SG:63) by Materials Project

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Kristin Persson

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  5. Materials Data on ErAl2Ni (SG:63) by Materials Project

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Kristin Persson

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  6. Materials Data on DyAlNi (SG:189) by Materials Project

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Kristin Persson

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  7. Materials Data on ErAl4Ni (SG:63) by Materials Project

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Kristin Persson

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  8. Materials Data on Ho3(AlNi3)2 (SG:229) by Materials Project

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Kristin Persson

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  9. Materials Data on AlFe2Ni (SG:225) by Materials Project

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Kristin Persson

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  10. Structure and magnetic properties of Ce₃(Ni/Al/Ga)₁₁-A new phase

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield MunicipalTechnicalInformation FederatedInformation What'sfunction (Journal Article) | DOEwith

  11. Solution-based thermodynamic modeling of the Ni-Al-Mo system using

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail. (Conference)Feedback System in the CERNimmobilize spent electrochemical

  12. SF 6432-NI (04-95)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservation of Fe(II) byMultidayAlumni > The EnergyRyanPhysics6/14/11 Page 1 of6432-NI

  13. Ni(II) Salts and 2-Propanol Effect Catalytic Reductive Coupling of Epoxides and Alkynes

    E-Print Network [OSTI]

    Beaver, Matthew G.

    A Ni-catalyzed reductive coupling of alkynes and epoxides using Ni(II) salts and simple alcohol reducing agents is described. Whereas previously reported conditions relied on Ni(cod)2 and Et3B, this system has several ...

  14. Continuous spin reorientation transition in epitaxially grown antiferromagnetic NiO thin films

    E-Print Network [OSTI]

    Li, J.

    2011-01-01

    along certain crystal axis [e.g. , NiO(100)]. Thusthe r 2 p S z 2, NiO ( dMgO ) / S NiO should be an approximation in the small limit.

  15. Interdiffusion Behavior of Pt-Diffused gamma+gamma' Coatings on Ni-Based Superalloys

    SciTech Connect (OSTI)

    Zhang, Ying [Tennessee Technological University; Stacy, J P [Tennessee Technological University; Pint, Bruce A [ORNL; Haynes, James A [ORNL; Hazel, Brian T [GE Aviation; Nagaraj, Ben [GE Aviation

    2008-01-01

    Platinum-diffused {gamma} + {gamma}{prime} coatings ({approx} 20 at.% Al, {approx} 22 at.% Pt) were synthesized on Rene 142 and Rene N5 Ni-based superalloys by electroplating the substrates with {approx} 7 {micro}m of Pt, followed by an annealing treatment in vacuum at 1175 C. In order to study the compositional and microstructural evolution of these coatings at elevated temperatures, interdiffusion experiments were carried out on coated specimens in the temperature range of 900-1050 C for various durations. Composition profiles of the alloying elements in the {gamma} + {gamma}{prime} coatings before and after diffusion experiments were determined by electron probe microanalysis. Although the change of the Al content in the coatings was minimal under these interdiffusion conditions, the decrease of the Pt content and increase of the diffusion depth of Pt into the substrate alloys were significant. A preliminary diffusion model was used to estimate the Pt penetration depth after diffusion.

  16. Spectral Content of 22Na/44Ti Decay Data: Implications for a Solar Influence

    E-Print Network [OSTI]

    Daniel O'Keefe; Brittany L. Morreale; Robert H. Lee; John B. Buncher; Ephraim Fischbach; Tom Gruenwald; Jere H. Jenkins; Daniel Javorsek II; Peter A. Sturrock

    2012-12-10

    We report a reanalysis of data on the measured decay rate ratio $^{22}$Na/$^{44}$Ti which were originally published by Norman et al., and interpreted as supporting the conventional hypothesis that nuclear decay rates are constant and not affected by outside influences. We find upon a more detailed analysis of both the amplitude and the phase of the Norman data that they actually favor the presence of an annual variation in $^{22}$Na/$^{44}$Ti, albeit weakly. Moreover, this conclusion holds for a broad range of parameters describing the amplitude and phase of an annual sinusoidal variation in these data. The results from this and related analyses underscore the growing importance of phase considerations in understanding the possible influence of the Sun on nuclear decays. Our conclusions with respect to the phase of the Norman data are consistent with independent analyses of solar neutrino data obtained at Super-Kamiokande-I and the Sudbury Neutrino Observatory (SNO).

  17. Synthesis and electrochemical properties of NiO nanospindles

    SciTech Connect (OSTI)

    Zhou, Hai; Lv, Baoliang; Xu, Yao; Wu, Dong

    2014-02-01

    Graphical abstract: NiO nanospindles with a different electrochemical activity as compared to those previous reports were synthesized via an agglomeration–dissolution–recrystallization growth process without the addition of any surfactant. - Highlights: • NiO nanospindles were synthesized without the addition of any surfactant. • The agglomeration–dissolution–recrystallization growth process was used to explain the precursors’ formation process of the spindle-like NiO. • As-obtained spindle-like NiO showed a different electrochemical activity as compared to those previous reports. - Abstract: NiO nanospindles were successfully synthesized via a hydrothermal and post-treatment method. The as-synthesized nanospindles were about several hundred nanometers in width and about one micrometer in length. X-ray diffraction (XRD) analysis revealed that the spindle-like structure was cubic NiO phase crystalline. Scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) analysis indicated that these NiO nanospindles were of single crystal nature. On the basis of time-dependent experiments, a possible agglomeration–dissolution–recrystallization growth process was proposed to explain the formation process of the spindle-like precursors. The cyclic voltammetry (CV) measurement showed that the as-prepared spindle-like NiO exhibited a pseudo-capacitance behavior.

  18. Luminescence properties of the hybrid Si-Ni nanoparticles system

    E-Print Network [OSTI]

    Lalayan, A A; Movsesyan, H A

    2015-01-01

    The luminescence properties of the colloidal hybrid Si - Ni nanoparticles system fabricated in the pure water by pulsed laser ablation is considered. The red-shifted photoluminescence of this system because of the Stark effect in the Coulomb field of the charged Ni nanoparticles has been registered in the blue range of the spectrum.

  19. Effect of geometrical constraint condition on the formation of nanoscale twins in the Ni-based metallic glass composite

    SciTech Connect (OSTI)

    Lee, M.H.; Kim, B.S.; Kim, D.H.; Ott, R.T.; Sansoz, F.; Eckert, J.

    2014-04-25

    We investigated the effect of geometrically constrained stress-strain conditions on the formation of nanotwins in alpha-brass phase reinforced Ni59Zr20Ti16Si2Sn3 metallic glass (MG) matrix deformed under macroscopic uniaxial compression. The specific geometrically constrained conditions in the samples lead to a deviation from a simple uniaxial state to a multi-axial stress state, for which nanocrystallization in the MG matrix together with nanoscale twinning of the brass reinforcement is observed in localized regions during plastic flow. The nanocrystals in the MG matrix and the appearance of the twinned structure in the reinforcements indicate that the strain energy is highly confined and the local stress reaches a very high level upon yielding. Both the effective distribution of reinforcements on the strain enhancement of composite and the effects of the complicated stress states on the development of nanotwins in the second-phase brass particles are discussed.

  20. In situ XAS of Ni-W hydrocracking catalysts.

    SciTech Connect (OSTI)

    Yang, N.; Mickelson, G. E.; Greenlay, N.; Kelly, S. D.; Bare, S. R.; UOP LLC; EXAFS Analysis

    2007-01-01

    Ni-W based catalysts are very attractive in hydrotreating of heavy oil due to their high hydrogenation activity. In the present research, two catalyst samples, prepared by different methods, that exhibit significant differences in activity were sulfided in situ, and the local structure of the Ni and W were studied using X-ray absorption spectroscopy (XAS). The Ni XANES spectra were analyzed using a linear component fitting, and the EXAFS spectra of the WS{sub 2} platelets in the sulfided catalysts were modeled. The Ni and W are fully sulfided in the higher activity sample, and there are both unsulfided Ni ({approx}25%) and W (<10%) in the lower activity sample.

  1. Morphology, deformation, and defect structures of TiCr{sub 2} in Ti-Cr alloys

    SciTech Connect (OSTI)

    Chen, K.C.; Allen, S.M.; Livingston, J.D.

    1992-12-31

    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.

  2. A Platinum-Enriched gamma+gamma' Two-Phase Bond Coat on Ni-Base Superalloys

    SciTech Connect (OSTI)

    Zhang, Ying [Tennessee Technological University; Pint, Bruce A [ORNL; Haynes, James A [ORNL; Wright, Ian G [ORNL

    2005-01-01

    Pt-enriched {gamma} + {gamma}{prime} two-phase coating was applied to directionally-solidified Ni-based superalloy Ren{acute e} 142 substrates with three different Hf levels (0.02, 0.76, and 1.37 wt.%). The coating was prepared by electroplating a thin layer of Pt on the superalloy followed by a diffusion treatment. The as-deposited coating exhibited a {gamma} + {gamma}{prime} two-phase microstructure with a major composition of Ni-16Al-18Pt-7Cr-9Co (in at.%) along with some incorporation of refractory elements from the substrates. Cyclic oxidation testing at 1100 C in air indicated improved oxidation resistance of the Ren{acute e} 142 alloys with the Pt-enriched {gamma} + {gamma}{prime} coatings. In addition, the oxidation resistance of both uncoated and coated alloys was proportional to the Hf content in the substrate. Compared with the single-phase {beta}-(Ni,Pt)Al coating, slightly higher mass gains and localized spallation were observed on the {gamma} + {gamma}{prime} two-phase coating, which might be due to the segregation of refractory elements and high sulfur levels in these superalloy substrates.

  3. SW 55 Ti ROTOR Used In Beckman Coulter

    E-Print Network [OSTI]

    Marchant, Jonathan

    SW 55 Ti ROTOR Used In Beckman Coulter Class H, R, and S Preparative Ultracentrifuges FPO L5-TB-062M August 2006 © 2006 Beckman Coulter, Inc. Printed in the U.S.A. #12;2 SW 55 Ti Rotor SAFETY NOTICE made by other manufacturers may fit in the SW 55 Ti rotor, their safety in this rotor cannot

  4. Carrier-Controlled Ferromagnetism in SrTiO3

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

    Moetakef, Pouya; Williams, James R.; Ouellette, Daniel G.; Kajdos, Adam P.; Goldhaber-Gordon, David; Allen, S. James; Stemmer, Susanne

    2012-06-01

    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 themore »thickness of the SrTiO3 quantum well. The results are used to construct a stability diagram for the ferromagnetic and superconducting phases of SrTiO3.« less

  5. Hydrides of CeNi/sub 5/, MmNi/sub 5/, Ca/sub 0/ /sub 2/(Ce/sub 0/ /sub 65/Mm/sub 0/ /sub 35/)/sub 0/ /sub 8/Ni/sub 5/, Ca/sub 0/ /sub 2/Ce/sub 0/ /sub 8/Ni/sub 5/, Ca/sub 0/ /sub 2/Mm/sub 0/ /sub 8/Ni/sub 5/, and mixed CeNi/sub 5//MmNi/sub 5/

    SciTech Connect (OSTI)

    Lakner, J.F.; Chow, T.S.

    1982-09-01

    Six intermetallic alloys (CeNi/sub 5/, MmNi/sub 5/, Ca/sub 0/ /sub 2/(Ce/sub 0/ /sub 65/Mm/sub 0/ /sub 35/)/sub 0/ /sub 8/Ni/sub 5/, Ca/sub 0/ /sub 2/Ce/sub 0/ /sub 8/Ni/sub 5/, Ca/sub 0/ /sub 2/Mm/sub 0/ /sub 8/Ni/sub 5/, and a mixed alloy, CeNi/sub 5//MmNi/sub 5/) were investigated with respect to their suitability to provide high hydrogen capacity and their potential for use in providing substantial hydrogen pressure at both low and high temperatures. A second phase of our investigation dealt with ball-milling and hydriding and dehydriding cycles to produce fine particles for use in hydride powder transfer studies. A summary of several Van't Hoff plots is also included for hydride-forming alloys.

  6. A=10Be (2004TI06)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion Batteries PrintA2 September 92004TI06)2004TI06) (See

  7. A=16Mg (1993TI07)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01) (Not93TI07) (Not illustrated) This nucleus93TI07)

  8. A=16Na (1993TI07)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01) (Not93TI07) (Not illustrated)71AJ02) (See93TI07)

  9. A=16Ne (1993TI07)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01) (Not93TI07) (Not illustrated)71AJ02)82AJ01)93TI07)

  10. A=16Si (1993TI07)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01) (Not93TI07) (Not1959AJ76) (See the71AJ02)93TI07)

  11. A=17Be (1993TI07)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01) (Not93TI07) (Not1959AJ76)93TI07) (Not illustrated)

  12. A=17F (1993TI07)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01) (Not93TI07)93TI07) (See Energy Level Diagrams for

  13. A=17Mg (1993TI07)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01) (Not93TI07)93TI07) (See Energy

  14. A=17O (1993TI07)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01) (Not93TI07)93TI07)82AJ01) (See Energy

  15. A=17P (1993TI07)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01) (Not93TI07)93TI07)82AJ01) (See

  16. A=18B (1995TI07)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01) (Not93TI07)93TI07)82AJ01) (SeeSi

  17. A=18Be (1995TI07)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01) (Not93TI07)93TI07)82AJ01) (SeeSi78AJ03)7AJ02)

  18. A=20Li (1998TI06)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01)72AJ02)78AJ03) (Not98TI06) (See EnergyLi (1998TI06)

  19. A=20Na (1998TI06)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01)72AJ02)78AJ03) (Not98TI06)3AJ01) (See Energy98TI06)

  20. A=3n (1987TI07)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01)72AJ02)78AJ03)98TI06) (See2010PU04)1987TI07) (Not

  1. A=4H (1992TI02)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01)72AJ02)78AJ03)98TI06) (See2010PU04)1987TI07)4A

  2. A=4HE (1992TI02)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01)72AJ02)78AJ03)98TI06) (See2010PU04)1987TI07)4AHe

  3. A=4Li (1992TI02)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01)72AJ02)78AJ03)98TI06) (See2010PU04)1987TI07)4AHeLi

  4. A=5H (2002TI10)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01)72AJ02)78AJ03)98TI06)5 - 74AJ01) (See2002TI10) (Not

  5. A=5He (2002TI10)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01)72AJ02)78AJ03)98TI06)5 - 74AJ01)4AJ01)2002TI10)

  6. Effects of Cr and Ni on Interdiffusion and Reaction between U and Fe-Cr-Ni Alloys

    SciTech Connect (OSTI)

    K. Huang; Y. Park; L. Zhou; K.R. Coffey; Y.H. Sohn; B.H. Sencer; J. R. Kennedy

    2014-08-01

    Metallic U-alloy fuel cladded in steel has been examined for high temperature fast reactor technology wherein the fuel cladding chemical interaction is a challenge that requires a fundamental and quantitative understanding. In order to study the fundamental diffusional interactions between U with Fe and the alloying effect of Cr and Ni, solid-to-solid diffusion couples were assembled between pure U and Fe, Fe–15 wt.%Cr or Fe–15 wt.%Cr–15 wt.%Ni alloy, and annealed at high temperature ranging from 580 to 700 °C. The microstructures and concentration profiles that developed from the diffusion anneal were examined by scanning electron microscopy, and X-ray energy dispersive spectroscopy (XEDS), respectively. Thick U6Fe and thin UFe2 phases were observed to develop with solubilities: up to 2.5 at.% Ni in U6(Fe,Ni), up to 20 at.%Cr in U(Fe, Cr)2, and up to 7 at.%Cr and 14 at.% Ni in U(Fe, Cr, Ni)2. The interdiffusion and reactions in the U vs. Fe and U vs. Fe–Cr–Ni exhibited a similar temperature dependence, while the U vs. Fe–Cr diffusion couples, without the presence of Ni, yielded greater activation energy for the growth of intermetallic phases – lower growth rate at lower temperature but higher growth rate at higher temperature.

  7. nh gi Tn tht Ti nguyn Thin nhin Trn du Deepwater Horizon D n Ci thin Tri nghim Ngi i B v Xe

    E-Print Network [OSTI]

    IVProposedEarlyRestorationProject MÔ T D ÁN D án ci thin vic s dng ng dành cho xe p và ngi i b ti Davis Bayou bao gm tng cng ci thin qua khi khong 10.000 c dân ã chuyn n các vùng lân cn. Ngi s dng tuyn ng giao thông công cng này bao gm sung c quy hoch và tng chn s c xây dng nhng ni có ng c nâng lên. D án cng bao gm vic xây dng bin báo

  8. Phase transformations in nickel-rich nickel-titanium alloys : influence of strain-rate, temperature, thermomechanical treatment and nickel composition on the shape memory and superelastic characteristics

    E-Print Network [OSTI]

    Adharapurapu, Raghavendra R.

    2007-01-01

    NiTi alloys using in- situ tranmission electron microscopyNiTi alloys using in- situ tranmission electron microscopy

  9. Giant persistent photoconductivity in BaTiO{sub 3}/TiO{sub 2} heterostructures

    SciTech Connect (OSTI)

    Plodinec, Milivoj; Šanti?, Ana; Gajovi?, Andreja; Zavašnik, Janez; ?eh, Miran

    2014-10-13

    The persistent photoconductivity (PPC) effect in nanotube arrays of barium titanate and TiO{sub 2} (BTO/TiO{sub 2}NT) was studied at room temperature under daylight illumination. The BTO/TiO{sub 2}NT heterostructures exhibited a giant PPC effect that was six orders of magnitude higher than the dark conductivity, followed by a slow relaxation for 3 h. The PPC in this material was explained by the existence of defects at the surfaces and the interfaces of the investigated heterostructures. The sample was prepared using a two-step synthesis: the anodization of a Ti-foil and a subsequent hydrothermal synthesis. The structural and electrical characteristics were studied by micro-Raman spectroscopy, field-emission-gun scanning electron microscopy, and impedance spectroscopy.

  10. Oblikoslovje v panonski nare?ni skupini

    E-Print Network [OSTI]

    Zorko, Zinka

    2010-01-01

    glagole: nes?, neseši, neset?; nesev?, neseta, nesete; nesem?, nesete, nes?t?; za atematske glagole: jesm?, jesi, jest?; jesv?, jesta, jeste; jesm?, jeste, s?t?. Slovenski knjižni jezik – tematska spregatev: nes-em, -eš, -e; -va, -ta, -ta; -mo, -te, -jo...; atematska spregatev: sem, si, je; sva, sta, sta; smo, ste, so. Prekmurš?ina (vsi glagoli se spregajo po temati?nem vzorcu): ne?s?:n, ne?s?:š, ne?s?:; ne?s?:va (m. sp.), ne?s?:ve (ž. sp.), ne?s?:ta, ne?s?:ta; ne?s?:mo, ne?s?:te, ne?s?:jo; ?sån, ?si, ?je; s...

  11. Ni/metal hydride secondary element

    DOE Patents [OSTI]

    Bauerlein, Peter

    2005-04-19

    A Ni/metal hydride secondary element having a positive nickel hydroxide electrode, a negative electrode having a hydrogen storage alloy, and an alkaline electrolyte, the positive electrode, provided with a three-dimensional metallic conductive structure, also contains an aluminum compound which is soluble in the electrolyte, in addition to nickel hydroxide and cobalt oxide. The aluminum compound is aluminum hydroxide and/or aluminum oxide, and the mass of the aluminum compound which is present in the positive bulk material mixture is 0.1 to 2% by weight relative to the mass of the nickel hydroxide which is present. In combination with aluminum hydroxide or aluminum oxide, the positive electrode further contains lanthanoid oxidic compounds Y.sub.2 O.sub.3, La.sub.2 O.sub.3 and Ca(OH).sub.2, as well as mixtures of these compounds.

  12. Effect of embedded metal nanocrystals on the resistive switching characteristics in NiN-based resistive random access memory cells

    SciTech Connect (OSTI)

    Yun, Min Ju; Kim, Hee-Dong; Man Hong, Seok; Hyun Park, Ju; Su Jeon, Dong; Geun Kim, Tae, E-mail: tgkim1@korea.ac.kr [School of Electrical Engineering, Korea University, Seoul 136-701 (Korea, Republic of)

    2014-03-07

    The metal nanocrystals (NCs) embedded-NiN-based resistive random access memory cells are demonstrated using several metal NCs (i.e., Pt, Ni, and Ti) with different physical parameters in order to investigate the metal NC's dependence on resistive switching (RS) characteristics. First, depending on the electronegativity of metal, the size of metal NCs is determined and this affects the operating current of memory cells. If metal NCs with high electronegativity are incorporated, the size of the NCs is reduced; hence, the operating current is reduced owing to the reduced density of the electric field around the metal NCs. Second, the potential wells are formed by the difference of work function between the metal NCs and active layer, and the barrier height of the potential wells affects the level of operating voltage as well as the conduction mechanism of metal NCs embedded memory cells. Therefore, by understanding these correlations between the active layer and embedded metal NCs, we can optimize the RS properties of metal NCs embedded memory cells as well as predict their conduction mechanisms.

  13. Development of metallization for GaAs and AlGaAs concentrator solar cells

    SciTech Connect (OSTI)

    Tobin, S.P.

    1987-04-01

    A three-layer metallization system was developed for high temperature stability on GaAs and AlGaAs solar cells. The layers are a Pt ohmic contact metal that forms thermally stable compounds with GaAs, a TiN diffusion barrier, and a gold conductor. The solar cell structure was also designed for contact stability, with the key component being a heavily doped GaAs cap layer. Reactively sputtered TiN was found to act as an excellent barrier when deposited under the proper conditions. The conditions were carefully optimized for low resistivity and low stress in the films. A low but nonzero substrate bias during sputtering was found to be important. Solar cells with sputtered metallizations of Pt/TiN/Ti/Pt/Au were found to be thermally stable up to 500/sup 0/C for 15 minutes in vacuum. At 600/sup 0/C there was catastrophic degradation of the cells due to dissociation of uncapped GaAs surfaces. Below this temperature the metallization performed as designed. The Pt and GaAs layers reacted to form a stable PtGa compound layer that gave low contact resistance. There was no penetration of Au or GaAs through the barrier layer. These results are a very encouraging first step leading to stable, reliable GaAs and AlGaAs concentrator cells.

  14. Graphene Monolayer Rotation on Ni(111) Facilities Bilayer Graphene Growth

    SciTech Connect (OSTI)

    Batzill M.; Sutter P.; Dahal, A.; Addou, R.

    2012-06-11

    Synthesis of bilayer graphene by chemical vapor deposition is of importance for graphene-based field effect devices. Here, we demonstrate that bilayer graphene preferentially grows by carbon-segregation under graphene sheets that are rotated relative to a Ni(111) substrate. Rotated graphene monolayer films can be synthesized at growth temperatures above 650 C on a Ni(111) thin-film. The segregated second graphene layer is in registry with the Ni(111) substrate and this suppresses further C-segregation, effectively self-limiting graphene formation to two layers.

  15. Magnetic properties of transition metal doped AlN nanosheet: First-principle studies

    SciTech Connect (OSTI)

    Shi, Changmin; Qin, Hongwei Zhang, Yongjia; Hu, Jifan; Ju, Lin

    2014-02-07

    We carry out our first-principles calculations within density functional theory to study the 3d transition metal (TM) doped AlN nanosheets. The calculated results indicate that a stoichiometric AlN nanosheet is graphene-like structure and nonmagnetic. The TM impurities can induce magnetic moments, localized mainly on the 3d TM atoms and neighboring N atoms. Our calculated results of TM-doped nanosheet systems indicate a strong interaction between 3d orbit of TM atom and the 2p orbit of N atoms. In addition, the Mn- and Ni-doped AlN nanosheet with half-metal characters seems to be good candidates for spintronic applications. When substituting two Al atoms, the relative energies of the states between ferromagnetic and antiferromagnetic coupling are investigated sufficiently. The exchange coupling of Co- and Ni-doped AlN nanosheets exhibits a transformation with different distances of two TM atoms and that of Cr-, Mn-, and Fe-doped AlN nanosheets is not changed.

  16. Effects of Process Conditions on Properties of Electroplated Ni Thin Films for Microsystem Applications

    E-Print Network [OSTI]

    Fleck, Norman A.

    Effects of Process Conditions on Properties of Electroplated Ni Thin Films for Microsystem, Southampton SO17 1QJ, United Kingdom The properties of electroplated Ni thin films have been systematically, micromotors, and pneumatic actuators.3-11 Ni and NiFe are the electroplated metals most commonly used for MEMS

  17. Perpendicular magnetic anisotropy in ion beam sputtered Co/Ni multilayers

    E-Print Network [OSTI]

    Rasin, Boris

    2009-01-01

    Co/Ni multilayers display perpendicular magnetic anisotropy and have applications in magnetic devices that could lead to a large increase in the density of magnetic storage. Co/Ni 10-(2 Å Co/ 8Å Ni) and 10-(2 Å Co/ 4 Å Ni) ...

  18. Ann bay lodyans 9 / se Bryant Freeman ("Tonton Liben") ki pare ti liv sa a

    E-Print Network [OSTI]

    Freeman, Bryant C.

    2000-01-01

    Liben”) ki pare ti liv sa a. [Lawrence, Kan.] : Institute of Haitian Studies ; [Port-au-Prince] : Bon Nouvèl : Fondasyon Alfa Lwès, 2000. Terms of Use: http://www2.ku.edu/~scholar/docs/license.shtml MARYAJ MALIS TWOUKOUKOU Vwala se Malis ki gen yon sel... rantre nan chanm Ian ak yon lanp. Yo gade, epi yo we moun ak mouchwa wouj la. Yo peze kou moun ak foula a jous li toufe, epi yo ale. Nan denmen maten, Malis leve. L al di yo: "Mezanmi, mesi anpil. M gen lontan m pa gen yon bon nwit kon sa...

  19. Ann bay lodyans 8 / se Bryant Freeman ("Tonton Liben") ki pare ti liv sa a

    E-Print Network [OSTI]

    Freeman, Bryant C.

    2000-01-01

    Liben”) ki pare ti liv sa a. [Lawrence, Kan.] : Institute of Haitian Studies ; [Port-au-Prince] : Bon Nouvèl : Fondasyon Alfa Lwès, 2000. Terms of Use: http://www2.ku.edu/~scholar/docs/license.shtml YON TOTI K AP CHANTE Vwala te gen yon neg yo rele... Gwoje. Msye te konn plante diri. Chak ane li pa janm ka fe bon rekot. Bet yo pran tout plezi yo nan manje jaden diri a. Se konsa, Gwoje blije mete veye pou trape vole k ap depafini jaden I la. Yon jou, pandan Pijon ak Kanna ap soti pou al nan jaden...

  20. Measurement of the $^{44}$Ti($\\alpha$,p)$^{47}$V reaction cross section, of relevance to gamma-ray observation of core collapse supernovae, using reclaimed $^{44}$Ti.

    E-Print Network [OSTI]

    Murphy, Alexander

    2015-01-01

    Measurement of the $^{44}$Ti($\\alpha$,p)$^{47}$V reaction cross section, of relevance to gamma-ray observation of core collapse supernovae, using reclaimed $^{44}$Ti.

  1. Ni(NiO)/single-walled carbon nanotubes composite: Synthesis of electro-deposition, gas sensing property for NO gas and density functional theory calculation

    SciTech Connect (OSTI)

    Li, Li; Zhang, Guo; Chen, Lei; Bi, Hong-Mei; Shi, Ke-Ying

    2013-02-15

    Graphical abstract: The Ni(NiO)/semiconducting single-walled carbon nanotubes composite collected from the cathode after electro-deposition shows a high sensitivity to low-concentration NO gas at room temperature (18 °C). Display Omitted Highlights: ? Ni(NiO) nanoparticles were deposited on semiconducting SWCNTs by electro-deposition. ? Ni(NiO)/semiconducting SWCNTs film shows a high sensitivity to NO gas at 18 °C. ?Theoretical calculation reveals electron transfer from SWCNTs to NO via Ni. -- Abstract: Single-walled carbon nanotubes which contains metallic SWCNTs (m-SWCNTs) and semiconducting SWCNTs (s-SWCNTs) have been obtained under electric arc discharge. Their separation can be effectively achieved by the electro-deposition method. The Ni(NiO)/s-SWCNTs composite was found on cathode where Ni was partially oxidized to NiO at ambient condition with Ni(NiO) nanoparticles deposited uniformly on the bundles of SWCNTs. These results were confirmed by Raman spectra, transmission electron microscopy (TEM), scanning electron microscopy (SEM), UV–vis–NIR and TG characterizations. Furthermore, investigation of the gas sensing property of Ni(NiO)/s-SWCNTs composite film to NO gas at 18 °C demonstrated the sensitivity was approximately 5% at the concentration of 97 ppb. Moreover, density functional theory (DFT) calculations were performed to explore the sensing mechanism which suggested the adsorption of NO molecules onto the composite through N–Ni interaction as well as the proposition of electron transfer mechanisms from SWCNTs to NO via the Ni medium.

  2. $^{64}$Ni+$^{64}$Ni fusion reaction calculated with the density-constrained time-dependent Hartree-Fock formalism

    E-Print Network [OSTI]

    A. S. Umar; V. E. Oberacker

    2007-09-25

    We study fusion reactions of the $^{64}$Ni+$^{64}$Ni system using the density-constrained time-dependent Hartree-Fock (TDHF) formalism. In this formalism the fusion barriers are directly obtained from TDHF dynamics. In addition, we incorporate the entrance channel alignments of the slightly deformed (oblate) $^{64}$Ni nuclei due to dynamical Coulomb excitation. We show that alignment leads to a fusion barrier distribution and alters the naive picture for defining which energies are actually sub-barrier. We also show that core polarization effects could play a significant role in fusion cross section calculations.

  3. Electrodeposition of amorphous matrix Ni-W/Wp̳ composites

    E-Print Network [OSTI]

    Jenket, Donald R. (Donald Robert)

    2005-01-01

    An amorphous Ni-W alloy matrix was incorporated with W particulate through two types of electrodeposition. The plating bath for the electrodeposition contained nickel sulfate, sodium tungstate, sodium citrate, ammonium ...

  4. Double dumbbell shaped AgNi alloy by pulsed electrodeposition

    SciTech Connect (OSTI)

    Dhanapal, K.; Vasumathi, M.; Santhi, Kalavathy [Materials Science Centre, Department of Nuclear Physics, University of Madras, Guindy Campus, Chennai 600 025 (India); Narayanan, V., E-mail: stephen-arum@hotmail.com; Stephen, A., E-mail: stephen-arum@hotmail.com [Department of Inorganic Chemistry, University of Madras, Guindy Campus, Chennai-600 025 (India)

    2014-01-28

    Silver-Nickel is the well-known thermally immiscible system that makes them quite complex for the formation of alloy. This kind of alloy can be attained from electrodeposition method. In the present work, AgNi alloy was synthesized by pulsed electrodeposition in a single bath two electrode system with the use of anodic alumina membrane. The prepared AgNi alloy and pure Ag were characterized with X-ray Diffraction (XRD) for structural confirmation, Scanning Electron Microscopy (SEM) for morphological, and magnetic properties by Vibrating Sample Magnetometer, respectively. The X-ray Diffraction study shows the formation of cubic structure for pure Ag. SEM analysis reveals the double dumbbell morphology for AgNi alloy and spherically agglomeration for pure silver. Hysteresis behaviour from VSM measurement indicates that the AgNi alloy have good ferro-magnetic properties.

  5. Grain boundary relaxation strengthening of nanocrystalline Ni–W alloys

    E-Print Network [OSTI]

    Rupert, Timothy J.

    The hardening effect caused by the relaxation of nonequilibrium grain boundary structure has been explored in nanocrystalline Ni–W alloys. First, the kinetics of relaxation hardening are studied, showing that higher annealing ...

  6. Effect of reinforcing particle type on morphology and age-hardening behavior of Al–4.5 wt.% Cu based nanocomposites synthesized through mechanical milling

    SciTech Connect (OSTI)

    Mostaed, A.; Saghafian, H.; Mostaed, E.; Shokuhfar, A.; Rezaie, H.R.

    2013-02-15

    The effects of reinforcing particle type (SiC and TiC) on morphology and precipitation hardening behavior of Al–4.5%Cu based nanocomposites synthesized via mechanical milling were investigated in the current work. In order to study the microstructure and morphology of mechanically milled powder, X-ray diffraction technique, scanning electron microscopy and high resolution transmission electron microscopy were utilized. Results revealed that at the early stages of mechanical milling, when reinforcing particles are polycrystal, the alloying process is enhanced more in the case of using the TiC particles as reinforcement. But, at the final stages of mechanical milling, when reinforcing particles are single crystal, the alloying process is enhanced more in the case of using the SiC ones. Transmission electron microscopy results demonstrated that Al–4.5 wt.%Cu based nanocomposite powders were synthesized and confirmed that the mutual diffusion of aluminum and copper occurs through the interfacial plane of (200). The hardness results showed that not only does introducing 4 vol.% of reinforcing particles (SiC or TiC) considerably decrease the porosity of the bulk composite samples, but also it approximately doubles the hardness of Al–4.5 wt.%Cu alloy (53.4 HB). Finally, apart from TEM and scanning electron microscopy observation which are localized, a decline in hardness in the TiC and SiC contained samples, respectively, after 1.5 and 2 h aging time at 473 K proves the fact that the size of SiC particles is smaller than the size of the TiC ones. - Highlights: ? HRTEM results show mutual diffusion of Al and Cu occurs through the (200) planes. ? TiC particles enhance alloying process more than the SiC ones at the early stages of MM. ? SiC particles enhance alloying process more than the TiC ones at the final stages of MM.

  7. Structural and Morphological Difference Between Ti/TiN/TiCN Coatings Grown in Multilayer and Graded Form

    SciTech Connect (OSTI)

    Restrepo, E.; Baena, A.; Agudelo, C.; Castillo, H.; Devia, A.; Marino, A.

    2006-12-04

    Thin films can be grown in super-lattice, multilayers and graded form, having each one advantages and disadvantages. The difference between multilayer and graded coatings is the interface. In multilayers the interface is abrupt and in graded coatings it is diffuse. The interface influences many chemical and physical properties of the materials, and its choice depends on the application. Graded coatings have the advantage of having gradual properties such as thermal expansion coefficient and lattice parameter, avoiding adherence problems due to good match between their component materials. In this work the comparison between some properties of coatings grown as multilayer and graded is performed. The materials are produced using the sputtering DC technique because of its facility to control the deposition parameters and generate a slow growth. The target is a disc of titanium and the samples are made of stainless steel 304. The working gases are argon, nitrogen and methane, which are mixed according to the material to be produced, i.e. Ti layer is grown with argon, the TiN film is produced with a mixture of argon and nitrogen, and the TiCN material is obtained mixing argon, nitrogen and methane. These materials are characterized with AFM in order to determine grain size and with XPS studying the chemical composition and performing depth profiles.

  8. EFFECTS OF PHASE TRANSFORMATIONS ON LASER FORMING OF Ti-6Al-4V ALLOY

    E-Print Network [OSTI]

    Yao, Y. Lawrence

    - ducing martensite ' or lamellae dependent on cooling rate, is also numerically investigated. The volume experiments. The results show that the method predicts flow be- havior of low carbon steel under transient complicated, and the product is martensitic ' or different morphology secondary phase de- pending on cooling

  9. Interactions Between Wear Mechanisms in a WC-Co / Ti-6Al-4V Machining Tribosystem 

    E-Print Network [OSTI]

    Bai, Qiong

    2014-12-11

    The objective of this research work is to identify and analyze the interactions between wear mechanisms in a machining tribosystem, and to confirm the fundamental physicochemical material interaction behavior through tribometric tests. The machining...

  10. Recyclability study on Inconel 718 and Ti-6Al-4V powders for...

    Office of Scientific and Technical Information (OSTI)

    beam melting In this study, powder bed based additive manufacturing technologies offer a big advantage in terms of reusability of the powders over multiple cycles that...

  11. Materials Data on TiAlAu2 (SG:225) by Materials Project

    SciTech Connect (OSTI)

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  12. Catalytic Effect of Ti for Hydrogen Cycling in NaAlH4 | Department of

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:FinancingPetroleum Based Fuels| Departmentof5.4.407.Cascade reactionsUsingMeeting: May01 DOE0

  13. Recyclability study on Inconel 718 and Ti-6Al-4V powders for use in

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTech ConnectSpeedingConnect(Conference) |(Patent) | SciTech Connect

  14. Anomalous magnetic behavior in nanocomposite materials of reduced graphene oxide-Ni/NiFe{sub 2}O{sub 4}

    SciTech Connect (OSTI)

    Kollu, Pratap E-mail: anirmalagrace@vit.ac.in; Prathapani, Sateesh; Varaprasadarao, Eswara K.; Mallick, Sudhanshu; Bahadur, D. E-mail: anirmalagrace@vit.ac.in; Santosh, Chella; Grace, Andrews Nirmala E-mail: anirmalagrace@vit.ac.in

    2014-08-04

    Magnetic Reduced Graphene Oxide-Nickel/NiFe{sub 2}O{sub 4} (RGO-Ni/NF) nanocomposite has been synthesized by one pot solvothermal method. Respective phase formations and their purities in the composite are confirmed by High Resolution Transmission Electron Microscope and X Ray Diffraction, respectively. For the RGO-Ni/NF composite material finite-size effects lead to the anomalous magnetic behavior, which is corroborated in temperature and field dependent magnetization curves. Here, we are reporting the behavior of higher magnetization values for Zero Field Cooled condition to that of Field Cooled for the RGO-Ni/NF nanocomposite. Also, the observed negative and positive moments in Hysteresis loops at relatively smaller applied fields (100?Oe and 200?Oe) are explained on the basis of surface spin disorder.

  15. A=6H (2002TI10)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01)72AJ02)78AJ03)98TI06)58AJ01)79AJ01)4AJ01)2002TI10)

  16. Multiscale Constitutive Modeling and Numerical Simulations of the Thermomechanical Response of Polycrystalline NiTi Shape Memory Alloy

    E-Print Network [OSTI]

    Sengupta, Arkaprabha

    2010-01-01

    in Section 2.1.2. In crystal plasticity, the inelasticof plasticity and phase transformation in single-crystals or

  17. nh Gi Tn Hi Ti Nguyn Thin Nhin do Trn Du Deep Horizon Gim nh bt Nhm Tng ni

    E-Print Network [OSTI]

    vàng và cá kim. Thit b dây câu vàng s vô tình bt phi nhng loài cá khác cng nh nhng cá th còn quá nh ca là thi gian ngh ngi. Các d án cng cung cp cho nhng ng dân tham gia hai loi thit b ánh bt thay th - tr

  18. Characterization and 3-D Modeling of Ni60Ti SMA for Actuation of a Variable Geometry Jet Engine Chevron

    E-Print Network [OSTI]

    to defined thermal inputs. Keywords: shape memory alloys, SMA, Nitinol, jet engine chevrons, shape control

  19. Development of Powder Diffraction Analysis Tools for aNanocrystalline Specimen: An Emphasis upon NiTi (Nitinol)

    SciTech Connect (OSTI)

    Owens, Erich; /Albion Coll. /SLAC

    2006-08-30

    Powder diffraction is a specialized technique whose investigatory limits are constrained by the scale of the crystallized substance being scanned versus the probe beam used. When disparate in scale, with the photon spot size larger than the crystal being probed, many are employed, the resulting diffraction image being cast from all possible incident angles, constructing {chi}-arcs containing information about the crystalline structure of the material under examination. Of particular interest to our collaboration is the structure of Nitinol, a superelastic Nickel-Titanium alloy, whose phase transformations and load bearing deformations can be studied by usage of diffraction, with wide sweeping biomedical uses. Analysis of this data is complicated by phase transformation and material fluorescence, which make difficult the computational modeling of the peaks within concentric {chi}-arcs. We endeavored to construct a series of computational tools (the amalgamation of them known as 2DPeakFinder) for refining and extracting this relevant data, toward the end of employing previously developed algorithms in the material's structural analysis. We succeeded to a large degree with the use of an iterative algorithm to navigate radial complexity of the signal and manage to retain a distinction between useful signal and superfluous background noise. The tools developed in this project are a small step in readily streamlining the analysis and physical modeling of a Nanocrystalline material's structural properties.

  20. Multiscale Constitutive Modeling and Numerical Simulations of the Thermomechanical Response of Polycrystalline NiTi Shape Memory Alloy

    E-Print Network [OSTI]

    Sengupta, Arkaprabha

    2010-01-01

    Phase transformation in Nitinol polycrystals 3.1 Martensiticvector pairs (m ? , b ? ) for Nitinol . . . . . . . . . . .4 Constitutive model of Nitinol 4.1 Constitutive models for

  1. Segregation At Stacking Faults Within The ?' Phase Of Two Ni-base Superalloys Following Intermediate Temperature Creep

    SciTech Connect (OSTI)

    Viswanathan, G. B.; Shi, R.; Genc, Arda; Vorontsov, V. A.; Kovarik, Libor; Rae, C.M. F.; Mills, M. J.

    2015-01-01

    Using state-of-the-art energy dispersive spectroscopy, it has been established for the first time that there exists significant compositional variation (enrichment of Co and Cr and deficiency of Ni and Al) associated with superlattice intrinsic stacking faults created in the ordered ?' precipitates following intermediate temperature deformation of two commercial superalloys. The results indicate that long range diffusion of these elements is intimately involved in the precipitate shearing process and is therefore closely linked to the time-dependent deformation of the alloys.

  2. Isotope correlations as a probe for freeze-out characterization: central 124Sn+64Ni, 112Sn+58Ni collisions

    E-Print Network [OSTI]

    E. Geraci; Reverse collaboration

    2003-10-15

    124Sn+64Ni and 112Sn+58Ni reactions at 35 AMeV incident energy were studied with the forward part of CHIMERA multi-detector. The most central collisions were selected by means of a multidimensional analysis. The characteristics of the source formed in the central collisions, as size, temperature and volume, were inspected. The measured isotopes of light fragments (3 <= Z <=8) were used to examine isotope yield ratios that provide information on the free neutron to proton densities.

  3. The performance of cermet cutting tools when machining an Ni-Cr-Mo (En 24) steel

    SciTech Connect (OSTI)

    Ezugwu, E.O.; Lim, S.K.

    1995-02-01

    Recently developed grades of cermet cutting tool materials, physical vapor deposition (PVD)-coated and uncoated, were used to machine a high-strength and relatively difficult-to-cut steel at cutting conditions typical of finish machining. Comparative tests were carried out with chemical vapor deposition (CVD)-coated (TiC + Al{sub 2}O{sub 3}) carbide inserts at similar cutting conditions. The test results show that the PVD-coated cermet tools outperformed both the uncoated cermet and CVD-coated carbide tools at higher speed conditions due to their increased mechanical and thermal shock resistance as well as the high lubricity of the TiN coating layer. The coated cermet tools were rejected mainly due to the generation of poor surface finish on the machined surface after prolonged machining due to the increased tool-workpiece contact area, with increasing flank wear, which permits access for dislodged hard particles into the interface. Plastic deformation of the cutting edge of the coated cermet tools tends to dampen the machining operation, leading to a reduction in both the cutting and feed forces. 9 refs., 10 figs., 1 tab.

  4. A Review Corrosion of TI Grade 7 and Other TI Alloys in Nuclear Waste Repository Environments

    SciTech Connect (OSTI)

    F. Hua; K. Mon; P. Pasupathi; G. Gordon

    2004-05-11

    Titanium alloy degradation modes are reviewed in relation to their performance in repository environments. General corrosion, localized corrosion, stress corrosion cracking, hydrogen induced cracking, microbially influenced corrosion, and radiation-assisted corrosion of Ti alloys are considered. With respect to the Ti Grade 7 drip shields selected for emplacement in the repository at Yucca Mountain, general corrosion, hydrogen induced cracking, and radiation-assisted corrosion will not lead to failure within the 10,000 year regulatory period; stress corrosion cracking (in the absence of disruptive events) is of no consequence to barrier performance; and localized corrosion and microbially influenced corrosion are not expected to occur. To facilitate the discussion, Ti Grades 2, 5, 7, 9, 11, 12, 16, 17, 18, and 24 are included in this review.

  5. Strain controlled metal-insulator transition in epitaxial NdNiO{sub 3} thin films

    SciTech Connect (OSTI)

    Xiang, P.-H. Zhong, N.; Duan, C.-G.; Tang, X. D.; Hu, Z. G.; Yang, P. X.; Zhu, Z. Q.; Chu, J. H.

    2013-12-28

    We have fabricated epitaxial thin films of NdNiO{sub 3} (NNO) on various single crystal substrates. The transport properties of NNO films are very sensitive to substrate-controlled epitaxial strain. As the strain varies from tensile to compressive, the Mott metal-insulator transition of NNO films shifts to low temperatures. Under a larger compressive strain, the film on LaSrAlO{sub 4} substrate exhibits a practically metallic transport characteristic. We have found that the conductivities of NNO films at low temperatures follow Mott's variable range hopping mechanism rather than thermal activation model and the epitaxial strain has a strong effect on Mott's parameters of NNO films. These findings demonstrate that the electronic transport of NNO thin films can be tuned by the epitaxial strain for next-generation perovskite-based microelectronic devices.

  6. Preparation and characterization of Ni(111)/graphene/Y{sub 2}O{sub 3}(111) heterostructures

    SciTech Connect (OSTI)

    Dahal, Arjun; Coy-Diaz, Horacio; Addou, Rafik; Lallo, James; Batzill, Matthias; Sutter, Eli

    2013-05-21

    Integration of graphene with other materials by direct growth, i.e., not using mechanical transfer procedures, is investigated on the example of metal/graphene/dielectric heterostructures. Such structures may become useful in spintronics applications using graphene as a spin-filter. Here, we systematically discuss the optimization of synthesis procedures for every layer of the heterostructure and characterize the material by imaging and diffraction methods. 300 nm thick contiguous (111) Ni-films are grown by physical vapor deposition on YSZ(111) or Al{sub 2}O{sub 3}(0001) substrates. Subsequently, chemical vapor deposition growth of graphene in ultra-high vacuum (UHV) is compared to tube-furnace synthesis. Only under UHV conditions, monolayer graphene in registry with Ni(111) has been obtained. In the tube furnace, mono- and bilayer graphene is obtained at growth temperatures of {approx}800 Degree-Sign C, while at 900 Degree-Sign C, non-uniform thick graphene multilayers are formed. Y{sub 2}O{sub 3} films grown by reactive molecular beam epitaxy in UHV covers the graphene/Ni(111) surface uniformly. Annealing to 500 Degree-Sign C results in crystallization of the yttria with a (111) surface orientation.

  7. Al Ogletree & Bob Tankersley 

    E-Print Network [OSTI]

    Unknown

    2011-08-17

    the installation and proper utilization of an EMCS.5 The objective of this report is to determine how successful Energy Management Control Systems have been in reducing energy consumption. 1 Claridge, D.E., et al 1994. "Energy retrofits can cut use and costs...." Mechanical Engineering, August, pp. 64-67. 2 Editor, 1991. Buildings, December, p. 16. 3 Editor, 1992. Buildings, September, p. 34. 4Mumford, S., 1994. Buildings, February, pp. 38-41. 5 Editor, 1993. Buildings, May, p 38. 1 The LoanSTAR Program6 In 1988...

  8. ALS Activity Reports

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  12. ALS Beamlines Directory

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  1. Artificial Photosynthesis on TiO2-Passivated InP Nanopillars

    E-Print Network [OSTI]

    2015-01-01

    of TiO 2 by atomic layer deposition. The role of theseof TiO 2 by atomic layer deposition. Plane wave-densitycontaminants. 8 Atomic layer deposition (ALD) of TiO 2 was

  2. Thermoelastic Analysis of a Vibrating TiB/Ti Cantilever Beam Using Differential Thermography

    SciTech Connect (OSTI)

    Byrd, Larry; Wyen, Travis; Byrd, Alex

    2008-02-15

    Differential thermography has been used to detect the fluctuating temperatures due the thermoelastic effect for a number of years. This paper examines functionally graded TiB/Ti cantilever beams excited on an electromechanical shaker in fully reversed bending. Finite difference analysis of specimens was used to look at the effect of heat conduction, convection and the fundamental frequency on the surface temperature distribution and compared to experimental data. The thermoelastic effect was also used to detect cracking and the stress field at the tip of the fixture during fatigue.

  3. INCREASED STRENGTHENING OF AUSTENITIC ALLOYS THROUGH DUAL AGING

    E-Print Network [OSTI]

    Ma, Annie

    2011-01-01

    Fe-Ni-Ti~Al aging heat treatments on hardened by austeniticcold working and thermal heat treatment. These tech- niques,the effect of solution heat treatment, single and du- plex

  4. A New Method of Low Cost Production of Ti Alloys to Reduce Energy...

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

    vehicle Benefits in "use phase" of Krollwrought Ti does not outweigh the energy consumption of manufacturing, but, HSPT Ti breaks even in six years compared with using...

  5. Film Coating Process Research and Characterization of TiN Coated Racetrack-type Ceramic Pipe

    E-Print Network [OSTI]

    Wang, Jie; Zhang, Bo; Wei, Wei; Fan, Le; Pei, Xiangtao; Hong, Yuanzhi; Wang, Yong

    2015-01-01

    TiN film was coated on the internal face of racetrack-type ceramic pipe by three different methods: radio-frequency sputtering, DC sputtering and DC magnetron sputtering. The deposition rates of TiN film under different coating methods were compared. According to the AFM, SEM, XPS test results,these properties were analyzed, such as TiN film roughness and surface morphology. At the same time, the deposition rates were studied under two types' cathode, Ti wires and Ti plate. According to the SEM test results, Ti plate cathode can improve the TiN/Ti film deposition rate obviously.

  6. Solving the stellar 62Ni problem with AMS

    E-Print Network [OSTI]

    I. Dillmann; T. Faestermann; G. Korschinek; J. Lachner; M. Maiti; M. Poutivtsev; G. Rugel; S. Walter; F. Käppeler; M. Erhard; A. R. Junghans; C. Nair; R. Schwengner; A. Wagner

    2009-07-01

    An accurate knowledge of the neutron capture cross sections of 62,63Ni is crucial since both isotopes take key positions which affect the whole reaction flow in the weak s process up to A=90. No experimental value for the 63Ni(n,gamma) cross section exists so far, and until recently the experimental values for 62Ni(n,gamma) at stellar temperatures (kT=30 keV) ranged between 12 and 37 mb. This latter discrepancy could now be solved by two activations with following AMS using the GAMS setup at the Munich tandem accelerator which are also in perfect agreement with a recent time-of-flight measurement. The resulting (preliminary) Maxwellian cross section at kT=30 keV was determined to be 30keV = 23.4 +/- 4.6 mb. Additionally, we have measured the 64Ni(gamma,n)63Ni cross section close to threshold. Photoactivations at 13.5 MeV, 11.4 MeV and 10.3 MeV were carried out with the ELBE accelerator at Forschungszentrum Dresden-Rossendorf. A first AMS measurement of the sample activated at 13.5 MeV revealed a cross section smaller by more than a factor of 2 compared to NON-SMOKER predictions.

  7. Modified Ni-Cu catalysts for ethanol steam reforming

    SciTech Connect (OSTI)

    Dan, M.; Mihet, M.; Almasan, V.; Borodi, G.; Katona, G.; Muresan, L.; Lazar, M. D.

    2013-11-13

    Three Ni-Cu catalysts, having different Cu content, supported on ?-alumina were synthesized by wet co-impregnation method, characterized and tested in the ethanol steam reforming (ESR) reaction. The catalysts were characterized for determination of: total surface area and porosity (N{sub 2} adsorption - desorption using BET and Dollimer Heal methods), Ni surface area (hydrogen chemisorption), crystallinity and Ni crystallites size (X-Ray Diffraction), type of catalytic active centers (Hydrogen Temperature Programmed Reduction). Total surface area and Ni crystallites size are not significantly influenced by the addition of Cu, while Ni surface area is drastically diminished by increasing of Cu concentration. Steam reforming experiments were performed at atmospheric pressure, temperature range 150-350°C, and ethanol - water molar ration of 1 at 30, using Ar as carrier gas. Ethanol conversion and hydrogen production increase by the addition of Cu. At 350°C there is a direct connection between hydrogen production and Cu concentration. Catalysts deactivation in 24h time on stream was studied by Transmission Electron Microscopy (TEM) and temperature-programmed reduction (TPR) on used catalysts. Coke deposition was observed at all studied temperatures; at 150°C amorphous carbon was evidenced, while at 350°C crystalline, filamentous carbon is formed.

  8. Superior performance of Ni-W-Ce mixed-metal oxide catalysts for ethanol steam reforming: Synergistic effects of W- and Ni-dopants

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

    Rodriguez, Jose A.; Liu, Zongyuan; Xu, Wenqian; Yao, Siyu; Johnson-Peck, Aaron C.; Zhao, Fuzhen; Michorczyk, Piotr; Kubacka, Anna; Stach, Eric A.; Fernandez-Garica, Marcos; et al

    2014-11-26

    The ethanol steam reforming (ESR) reaction was studied over a series of Ni-W-Ce oxide catalysts. The structures of the catalysts were characterized using in-situ techniques including X-ray diffraction, Pair Distribution Function, X-ray absorption fine structure and transmission electron microscopy; while possible surface intermediates for the ESR reaction were investigated by Diffuse Reflectance Infrared Fourier Transform Spectroscopy. In these materials, all the W and part of the Ni were incorporated into the CeO? lattice, with the remaining Ni forming highly dispersed nano NiO (more »The Ni-W-Ce systeme exhibited a much larger lattice strain than those seen for Ni-Ce and W-Ce. Synergistic effects between Ni and W inside ceria produced a substantial amount of defects and O vacancies that led to high catalytic activity, selectivity and stability (i.e. resistance to coke formation) during ethanol steam reforming.« less

  9. Equation of State Model Quality Study for Ti and Ti64.

    SciTech Connect (OSTI)

    Wills, Ann Elisabet; Sanchez, Jason James

    2015-02-01

    Titanium and the titanium alloy Ti64 (6% aluminum, 4% vanadium and the balance ti- tanium) are materials used in many technologically important applications. To be able to computationally investigate and design these applications, accurate Equations of State (EOS) are needed and in many cases also additional constitutive relations. This report describes what data is available for constructing EOS for these two materials, and also describes some references giving data for stress-strain constitutive models. We also give some suggestions for projects to achieve improved EOS and constitutive models. In an appendix, we present a study of the 'cloud formation' issue observed in the ALEGRA code. This issue was one of the motivating factors for this literature search of available data for constructing improved EOS for Ti and Ti64. However, the study shows that the cloud formation issue is only marginally connected to the quality of the EOS, and, in fact, is a physical behavior of the system in question. We give some suggestions for settings in, and improvements of, the ALEGRA code to address this computational di culty.

  10. On the possibility of neutron generation in an imploding TiD{sub 2} puff Z pinch

    SciTech Connect (OSTI)

    Baksht, Rina B.; Tel-Aviv University, Tel Aviv ; Oreshkin, Vladimir I.; Tomsk Polytechnic University, Tomsk ; Rousskikh, Alexander G.

    2013-08-15

    Simulation of implosion of a TiD{sub 2} puff Z pinch is reported. The Z pinch is supposed to be produced by the plasma flow generated by a vacuum arc, as described by Rousskikh et al.[Phys. Plasmas 18, 092707 (2011)]. To simulate the implosion, a one-dimensional two-temperature radiative magnetohydrodynamics code was used. The simulation has shown that neutrons are generated during the implosion of a TiD{sub 2} puff Z pinch due to thermalization of the pinch plasma stagnated on axis. It has been shown that the necessary condition for neutron generation is that the ion temperature must be substantially higher than the electron temperature. For a pinch current of 1 MA, the predicted yield of 'thermal' neutrons is 2.5 × 10{sup 9} neutrons/shot.

  11. Mitigation of Sulfur Poisoning of Ni/Zirconia SOFC Anodes by Antimony and Tin

    SciTech Connect (OSTI)

    Marina, Olga A.; Coyle, Christopher A.; Engelhard, Mark H.; Pederson, Larry R.

    2011-02-28

    Surface Ni/Sb and Ni/Sb alloys were found to efficiently minimize the negative effects of sulfur on the performance of Ni/zirconia anode-supported solid oxide fuel cells (SOFC). Prior to operating on fuel gas containing low concentrations of H2S, the nickel/zirconia anodes were briefly exposed to antimony or tin vapor, which only slightly affected the SOFC performance. During the subsequent exposures to 1 and 5 ppm H2S, increases in anodic polarization losses were minimal compared to those observed for the standard nickel/zirconia anodes. Post-test XPS analyses showed that Sb and Sn tended to segregate to the surface of Ni particles, and further confirmed a significant reduction of adsorbed sulfur on the Ni surface in Ni/Sn and Ni/Sb samples compared to the Ni. The effect may be the result of weaker sulfur adsorption on bimetallic surfaces, adsorption site competition between sulfur and Sb or Sn on Ni, or other factors. The use of dilute binary alloys of Ni-Sb or Ni-Sn in the place of Ni, or brief exposure to Sb or Sn vapor, may be effective means to counteract the effects of sulfur poisoning in SOFC anodes and Ni catalysts. Other advantages, including suppression of coking or tailoring the anode composition for the internal reforming, are also expected.

  12. Bimetallic Fe-Ni Oxygen Carriers for Chemical Looping Combustion

    SciTech Connect (OSTI)

    Bhavsar, Saurabh; Veser, Goetz

    2013-11-06

    The relative abundance, low cost, and low toxicity of iron make Fe-based oxygen carriers of great interest for chemical looping combustion (CLC), an emerging technology for clean and efficient combustion of fossil and renewable fuels. However, Fe also shows much lower reactivity than other metals (such as Ni and Cu). Here, we demonstrate strong improvement of Fe-based carriers by alloying the metal phase with Ni. Through a combination of carrier synthesis and characterization with thermogravimetric and fixed-bed reactor studies, we demonstrate that the addition of Ni results in a significant enhancement in activity as well as an increase in selectivity for total oxidation. Furthermore, comparing alumina and ceria as support materials highlights the fact that reducible supports can result in a strong increase in oxygen carrier utilization.

  13. A=10B (2004TI06)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion Batteries PrintA2 September 92004TI06) (See Energy Level

  14. A=10F (2004TI06)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion Batteries PrintA2 September79AJ01)8AJ01) (Not2004TI06)

  15. A=10He (2004TI06)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion Batteries PrintA2 September79AJ01)8AJ01)4AJ01)2004TI06)

  16. A=10N (2004TI06)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion Batteries PrintA279AJ01) (See the2004TI06) (Not

  17. A=10Ne (2004TI06)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion Batteries PrintA279AJ01) (See the2004TI06)8AJ01)

  18. A=16B (1993TI07)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01) (Not illustrated)59AJ76) (See the93TI07) (Not

  19. A=16Be (1993TI07)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01) (Not illustrated)59AJ76) (See6AJ04) (Not93TI07)

  20. A=16C (1993TI07)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion1AJ01) (Not illustrated)59AJ76) (See6AJ04)82AJ01)93TI07)