Ab-initio calculation of the γ-surface and cleavage energy in the B2 FeCo intermetallic compound

The plastic-deformation behavior of the FeCo intermetallic compound with CsCl-type B2 structure is investigated using ab initio techniques. For that purpose, stacking-fault energies (intrinsic, extrinsic, and twinning), the entire gamma-surface, the shear strength, the cleavage energy, and the cleavage strength are calculated in {1 (1) over bar2} and {110} planes of the compound single crystal. Analyzing gamma-surfaces reveals the existence of stable anti-phase boundaries in both planes. Moreover, the favored slip system in this compound is found to be {110} [(1) over bar 11]. The brittle/ductile response of the material is investigated within the Rice model. It is found that both planes are equally important when investigating the brittle/ductile behavior of this compound. In agreement with observed experiments, the model successfully predicts the brittle behavior of this compound against an applied stress. (C) 2017 Elsevier B.V. All rights reserved.