Microstructure characteristic and its effect on mechanical and shape memory properties in a Fe-17Mn-8Si-0.3C alloy

The influences of the Si content on the mechanical and shape memory properties of Fe-17Mn-xSi-0.3C alloys (wt.%) were examined, and a specific focus was placed on the properties of the Fe-17Mn-8Si-0.3C alloy. The 8%Si addition changed the initial microstructure from an austenite to an austenite/ferrite dual phase. A sufficient amount of deformation-induced ε-martensite was observed despite the pre-existing ferrite. Mn and C were preferentially distributed to the austenite, while Si was localized in the ferrite. The formation of ferrite increased the yield strength and the shape recovery stress, and decreased the starting temperature for the shape recovery.