Tailoring Grain Boundary and Resultant Plasticity of Pure Iron by Pulsed-Electric-Current Treatment

In general, annealing twins (Σ3 boundaries) are induced in face-centered cubic metals by thermal–mechanical processes. We report on the Σ3 boundary-induced plasticity enhancement of pure iron treated by a pulsed electric current subject to its allotropic transformation of α → γ → α. The behavior is attributed to an increased amount of Σ3 boundaries with the grain-boundary interconnection evolution from {112}/{112} to {110}/{110} resulting from the increasing pulsed-electric-current intensity. The results provide an alternative pathway to fabricate high-performance metallic materials by tailoring special grain boundaries.