Interatomic potentials of embedded-atom type were developed for this system. The Fe-Ni pair potential was obtained by a fit to the properties of face-centered cubic Fe-Ni alloys. The Fe-Al and Ni-Al potentials had been derived from lattice and elastic properties of B2 FeAl and NiAl. The Fe-Ni potentials predicted a greater stability of the Fe-Ni face-centered cubic disordered equi-atomic phase with respect to the L10 and body-centered cubic phases. Shear-fault energies along the {110}-type planes in FeAl were computed and showed that stable planar faults deviated from the exact antiphase boundary fault. Core structures were simulated for the <100> dislocations. These dislocations dissociated into super-partials that were not exactly of ½<111>-type but were of ⅛<334>-type; in agreement with the calculated stable planar fault for {110} planes. The ternary potentials were used to simulate the B2-type ternary alloy, Ni-35Al-12Fe. The <100> screw dislocation was simulated for Ni-35Al-12Fe and compared with published results on the same dislocation in NiAl and FeAl. This showed that the behavior of the <100> screw dislocation in the ternary alloy could be considered to be intermediate between that in NiAl and FeAl. The dislocation always dissociated into 2 super-partials along a {110} plane; as observed in FeAl. However, the distance between these super-partials depended upon the distribution of atoms which was used in the simulation.

Interatomic Potentials and Dislocation Simulation for the Ternary B2 Ni-35Al-12Fe Alloy. C.Vailhe, D.Farkas: Materials Science and Engineering A, 1998, 258[1-2], 26-31