The impact of the 5d transition metals, Re and Pt, upon the yield stress anomaly of Ni3Al-based alloys was studied by evaluating the anisotropy ratio for the antiphase boundary energies using first-principles calculations. The completely relaxed {111} and {100} antiphase boundary energies of the Ni3Al-based alloys were calculated. It was found that Re preferred to occupy the Al site, but Pt preferred to occupy the Ni site. Both Pt and Re could increase the {111} and {100} antiphase boundary energies of the Ni3Al-based alloys. It was found that only when the coverage of alloying element Re or Pt in the slip plane of antiphase boundaries was less than a certain critical value the anisotropy ratio for the antiphase boundary energies of the corresponding could the alloy meet the cross-slip condition within the Paidar-Pope-Vitek model and the yield stress anomaly could occur. An approach was described which could be used to calculate the antiphase boundary energy of the multi-component alloys. The results could provide a good guide to the selection, preparation and application of Ni3Al intermetallics.

First-Principle Calculation of Yield Stress Anomaly of Ni3Al-Based Alloys. Lü, B.L., Chen, G.Q., Qu, S., Su, H., Zhou, W.L.: Materials Science and Engineering A, 2013, 565, 317-20