Analysis of the Stress-Strain Curves of a Fe-Mn-Si Shape Memory Alloy

The stress-induced martensitic transformation of an Fe-30(wt.%)Mn-6(wt.%)Si shape memory alloy has been studied through the tensile deformation and the recovery processes. The results show that the deformation process of Fe-Mn-Si shape memory alloys can be divided into three stages with different mechanisms. The first stage is the elastic stage, the second one is related to the γ → ϵ phase transformation, and the third one can be described as plastic deformation. An appropriate thermomechanical training procedure can markedly increase the recovery rate to close to 100%.