Mechanism of reversible transformation-induced plasticity of Fe–Mn–Si shape memory alloys

The mechanism of reversible transformation-induced plasticity of an Fe–30Mn–6Si (mass %) shape memory alloy, under tensile stress and subsequent compression, has been observed by optical and atomic force microscopy. The tensile stress-induced ε (hexagonal close-packed) martensite reverts into γ (face-centered cubic) austenite after compression to zero strain. Further compression to negative strains induces a different ε martensite variant from that of the tensile-stress-induced ε martensite.