First-principle calculation of yield stress anomaly of Ni3Al-based alloys

Abstract

This paper studies the impact of 5d transition metals Re and Pt on yield stress anomaly of Ni3Al-based alloys by evaluating the anisotropy ratio for the APB energies using first principles calculations. The completely relaxed {111} and {100} APB energies of the Ni3Al-based alloys are calculated. It is found that alloying element Re prefers to occupy the Al site, but Pt prefers to occupy the Ni site. Both Pt and Re can increase {111} and {100} APB energies of the Ni3Al-based alloys. It is found that only when the coverage of alloying element Re or Pt in the slip plane of APBs is less than a certain critical value the anisotropy ratio for the APB energies of the corresponding alloy can meet the cross-slip condition within the Paidar–Pope–Vitek model and the yield stress anomaly can occur. The paper gives an approach which can calculate the antiphase boundary energy of the multi-component alloys. These results can provide a good reference to selection, preparation and application of the Ni3Al intermetallics.