Computer simulation methods were used to calculate the energies of planar defects in intermetallic Ni3Al alloyed with Cr, Fe, Nb. The calculations were for antiphase boundaries of the ½<110> {111} and ½<110> {001} type, complex stacking fault 1/6<112> {111}, and superstructure stacking fault 1/3<112>{111}. Analysis of calculated and published data showed that Fe and Nb atoms were distributed over Ni sites, with Cr atoms uniformly distributed over all the lattice sites. The way the relationship between antiphase boundary energies changed when Ni3Al was doped shows that the addition of Cr raised, and of Fe and Nb lowered, the activation energy of cross-slip. The data on the dependence of the energy of complex stacking faults and superstructure stacking fault on concentration of the alloying element led to the conclusion that Cr and Fe lowered, while Nb raised, the resistance of the Ni3Al lattice to a transition to superstructure DO19.

Influence of Alloying on the State of Planar Defects in Ordered Alloy Ni3Al. Starostenkov, M.D., Gorlov, N.V., Demyanov, B.F.: Physics of Metals and Metallography, 1989, 68[2], 17-21