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Author Asta, M. ♦ Morgan, D. ♦ Hoyt, J. J. ♦ Sadigh, B. ♦ Althoff, J. D. ♦ de Fontaine, D. ♦ Foiles, S. M.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword MATERIALS SCIENCE ♦ MIXING HEAT ♦ NICKEL ALLOYS ♦ ALUMINIUM ALLOYS ♦ THERMODYNAMICS ♦ ENTROPY ♦ ENTHALPY ♦ MONTE CARLO METHOD ♦ MIXING ♦ VISCOSITY ♦ SIMULATION ♦ ALUMINIUM ♦ MOLECULAR DYNAMICS METHOD
Abstract Structural, thermodynamic, and atomic-transport properties of liquid Ni-Al alloys have been studied by Monte Carlo and molecular-dynamics simulations based upon three different embedded-atom method (EAM) interatomic potentials, namely those due to Foiles and Daw (FD) [J. Mater. Res. {bold 2}, 5 (1987)], Voter and Chen (VC) [in {ital Characterization of Defects in Materials}, edited by R. W. Siegel {ital et al.} MRS Symposia Proceedings. No. 82 (Materials Research Society, Pittsburgh, 1987), p.175] and Ludwig and Gumbsch (LG) [Model. Simul. Mater. Sci. Eng. {bold 3}, 533 (1995)]. We present detailed comparisons between calculated results and experimental data for structure factors, atomic volumes, enthalpies of mixing, activities, and viscosities. Calculated partial structure factors are found to be in semiquantitative agreement with published neutron scattering measurements for Ni{sub 20}Al{sub 80} alloys, indicating that short-range order in the liquid phase is qualitatively well described. Calculated thermodynamic properties of mixing are found to agree very well with experimental data for Ni compositions greater than 75 atomic {percent}, while for alloys richer in Al the magnitudes of the enthalpies and entropies of mixing are significantly underestimated. The VC and LG potentials give atomic densities and viscosities in good agreement with experiment for Ni-rich compositions, while FD potentials consistently underestimate both properties at all concentrations. The results of this study demonstrate that VC and LG potentials provide a realistic description of the thermodynamic and atomic transport properties for Ni{sub x}Al{sub 1{minus}x} liquid alloys with x{ge}0.75, and point to the limitations of EAM potentials for alloys richer in Al. {copyright} {ital 1999} {ital The American Physical Society}
ISSN 01631829
Educational Use Research
Learning Resource Type Article
Publisher Date 1999-06-01
Publisher Place United States
Journal Physical Review, B: Condensed Matter
Volume Number 59
Issue Number 22


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