Texture evolution during thermomechanical treatments in Fe–Mn–Si shape memory alloys

Abstract

Texture evolution and shape memory behaviour were investigated in an Fe–30Mn–4Si (at.%) alloy showing the γ↔ɛ martensitic transformation. The alloy was subjected to different rolling and annealing treatments. Texture mapping and shape memory effect were performed in each case. After hot-rolling at 1000 °C, and for high values of accumulated strain, typical face-centered cubic (FCC) shear textures were observed for the austenitic phase. Further rolling at 600 °C leads to some texture reduction although the texture pattern remains unchanged. Alternatively, cold-rolling leads to stress-induced ɛ martensite and, after annealing at 650 °C, a similar FCC rolling texture was observed. Thus, different thermomechanical processes allow the development of quite different texture patterns that might be exploited for attaining novel shape memory responses. Shape recovery and yield stress were measured for the different specimens to analyze the role of texture and processing parameters on the shape memory effect.