Energy-Composition Relations in Ni₃(Al_1−xX_x) Phases

Abstract

The secondary phase, such as Ni3Al-based L12 γ′, is crucially important for the precipitation strengthening of superalloys. Composition–structure–property relations provide useful insights for guided alloy design. Here we use density functional theory combined with the multiple scattering theory to compute dependencies of the structural energies and equilibrium volumes versus composition for ternary Ni3(Al1−xXx) alloys with X = {Ti, Zr, Hf; V, Nb, Ta; Cr, Mo, W} in L12, D024, and D019 phases with a homogeneous chemical disorder on the (Al1−xXx) sublattice. Our results provide a better understanding of the physics in Ni3Al-based precipitates and facilitate the design of next-generation nickel superalloys with precipitation strengthening.

Keywords

• energy
• composition
• precipitation
• strengthening
• superalloys
• theory