Shear faults and dislocation core structure simulations in B2 FeAl

Embedded atom potentials were derived for the Fe-Al system reproducing lattice and elastic properties of B2 FeAl. The structure and energy of vacancies, antisites and anti phase boundaries (APBs) were studied. A significant decrease in the APE energy was obtained for Fe-rich B2 alloys. Shear fault energies along the {110} and {112} planes were computed showing that stable planar faults deviated from the exact APE fault. Care structures and critical Peierls stress values were simulated for the [100] and [111] dislocations. The superpartials created in the dissociation reactions were not of the 1/2[111] type, but 1/8[334] in accordance with the stable planar fault in the {110} planes. The results obtained for these simulations are discussed in terms of the mechanical behavior of FeAl and in comparison with B2 NiAl. (C) 1997 Acta Metallurgica Inc.