A first-principles method based on the projector augmented wave method within the generalized gradient approximation was used to calculate the superlattice intrinsic stacking fault and complex stacking fault energies of binary Ni3Al alloys with various Al contents and the ternary Ni3Al intermetallic alloys with addition of alloying elements, such as Pd, Pt, Ti, Mo, Ta, W and Re. The results showed that the energies of superlattice intrinsic stacking faults and complex stacking faults increased significantly with increasing Al contents in Ni3Al. The addition of Pd and Pt occupying the Ni sub-lattices did not change the superlattice intrinsic stacking fault and complex stacking fault energies of Ni3Al markedly in comparison with the Ni–23.75Al alloy. While the addition of alloying elements, such as Ti, Mo, Ta, W and Re, occupying the Al sub-lattices dramatically increased the superlattice intrinsic stacking fault and complex stacking fault energies of Ni3Al. The results suggested that the energies of superlattice intrinsic stacking fault and complex stacking fault were dependent upon both the Al content and on the site occupancy of the ternary alloying element in Ni3Al intermetallic alloys.

First-Principles Study of Stacking Fault Energies in Ni3Al Intermetallic Alloys. Wen, Y., Sun, J., Huang, J.: Transactions of Nonferrous Metals Society of China, 2012, 22[3], 661-4