Configurationally exhaustive first-principles study of a quaternary superalloy with a vast configuration space

Exploration of the vast configuration space encountered in a multicomponent alloy is impossible without a suitable engine like the cluster-expansion (CE) method. While a CE ansatz can be formulated for an arbitrary number of components n, the combinatorial explosion of configuration space with increasing n can still be prohibitive. In this paper, we present a configurationally exhaustive study of a four-component nickel-based superalloy. We obtain all ground-state compounds, temperature- and concentration-dependent configurational energies, and micrographs of the γ/γ′ microstructure of the γ′-strengthened superalloy Ni-Al-Ta-W. Several phenomena that cannot be studied from the binary building blocks Ni-Al, Ni-W, or Ni-Ta alone are discussed, e.g., the suppression of γ′′ formation in Al-Ni-Ta-W, the effect of Ta on the γ′ composition, and the tungsten partitioning ratio as a function of both temperature and bulk composition.

DDC Class

530: Physics

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Configurationally exhaustive first-principles study of a quaternary superalloy with a vast configuration space