Ab initio simulations of molten Ni alloys

Christopher Woodward, Mark Asta, Dallas R. Trinkle, James Lill, Stefano Angioletti-Uberti

Research output: Contribution to journalArticle

Abstract

Convective instabilities responsible for misoriented grains in directionally solidified turbine airfoils are produced by variations in liquid-metal density with composition and temperature across the solidification zone. Here, fundamental properties of molten Ni-based alloys, required for modeling these instabilities, are calculated using ab initio molecular dynamics simulations. Equations of state are derived from constant number-volume- temperature ensembles at 1830 and 1750 K for elemental, binary (Ni-X, X=Al, W, Re, and Ta) and ternary (Ni-Al-X, X=W, Re, and Ta) Ni alloys. Calculated molar volumes agree to within 0.6%-1.8% of available measurements. Predictions are used to investigate the range of accuracy of a parameterization of molar volumes with composition and temperature based on measurements of binary alloys. Structural analysis reveals a pronounced tendency for icosahedral short-range order for Ni-W and Ni-Re alloys and the calculations provide estimates of diffusion rates and their dependence on compositions and temperature.

Original languageEnglish (US)
Article number113522
JournalJournal of Applied Physics
Volume107
Issue number11
DOIs
StatePublished - Jun 1 2010

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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    Woodward, C., Asta, M., Trinkle, D. R., Lill, J., & Angioletti-Uberti, S. (2010). Ab initio simulations of molten Ni alloys. Journal of Applied Physics, 107(11), [113522]. https://doi.org/10.1063/1.3437644