Synthesis and characterization of Fe–Mn–Si shape memory alloy by mechanical alloying and subsequent sintering

An Fe‐Mn‐Si bulk alloy was produced from elemental powders by mechanical alloying (MA) and subsequent sintering. The shape memory effect, microstructure and mechanical property of the bulk alloy were investigated. The α phase transformed into the γ phase during MA. The MA played an essential role in stabilizing the γ phase, which is associated with the shape memory effect in this alloy system. The γ phase with small amounts of ε and α′ martensitic phases formed after subsequent sintering. After deformation, a γ→ε stress-induced martensitic phase transformation occurred. Shape recovery was observed after subsequent heating, associated with an ε→γ reverse martensitic transformation. The grain size of the bulk alloy was about 2–3 μm, and the yield strength was about 500 MPa. These results show that powder metallurgy, a combination of MA and subsequent sintering, has the potential to produce Fe–Mn–Si shape memory alloy.