Neutron diffraction characterisation of thermomechanical behaviour of Fe–Mn–Si shape memory alloy

Abstract

Time-of-flight neutron diffraction profiles were recorded in situ during uniaxial tensile loading and subsequent annealing of an Fe–Mn–Si shape memory alloy. Results are presented on the evolution of phase textures and internal strains. Stress-induced phase transformation occurred preferentially in austenite grains having a 〈110〉 direction aligned axially, and resulted in the formation of ϵ martensite with a {101} fibre texture. These results and the evolution of internal strains are rationalised by consideration of the Schmid factor for the motion of Shockley partial dislocations.