Formation of a nanocrystalline structure in the hard magnetic alloy Fe–30% Cr–23% Co during severe plastic deformation

The structure evolution and phase transformation of multiphase an Fe–Cr–Co alloy processed by severe plastic deformation is reviewed. Different initial coarse-grained structures were obtained by annealing at temperatures ranging from 540 to 1300°C. Room temperature severe plastic deformation by high-pressure torsion results in a partial transformation of the initial phases. It has been found that partial transformation of the σ phase into α phase as well as dissolution of α1+α2 phases leads to an increase of the strength and plasticity of Fe–30% Cr–23% Co alloy (wt.%).