Fabrication and characterization of nanostructured Fe–28Mn–6Si–5Cr shape memory alloy

Abstract

Mechanical alloying and consequent sintering techniques were used to create a bulk alloy of Fe–28Mn–6Si–5Cr from elemental powder. The microstructure and shape memory behavior due to bending deformation were investigated. The majority of α phases that existed at the start of the mechanical alloying process were changed into γ phases by the end of the 40-hour process. The γ phase was essential to achieving shape recovery behavior, which was boosted by mechanical alloying. A stress-induced γ to ε phase transformation occurred at the end of the bending deformation process. Shape recovery was observed after the subsequent heat treatment process due to reverse martensitic ε to γ phase transformation. After mechanical alloying, a grain size of 9.5 nm was attained and a considerable amount of shape recovery was achieved at the end of the recovery heat-treatment process. As a result, we came to the conclusion that combining mechanical alloying with powder metallurgy and then sintering has the potential to synthesize Fe-Mn-Si-Cr shape memory alloy.