Shear faults and dislocation core structure simulations in B2 FeAl

Abstract

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 APB 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 APB fault. Core 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.