Influence of deformation temperature on shape memory effect of Fe–Mn–Si–Ni–Cr alloy

Abstract

The phase transformation hypocrisy-elasticity behaviour and the shape memory completeness of four Fe–Mn–Si–Ni–Cr alloys deformed at different temperatures are reported. An incomplete phase transformation hypocrisy-elasticity caused by the γ→ε martensite reversible transformation is exhibited in an Fe–14Mn–5Si–9Cr–5Ni alloy at 473 K. The shape recovery completeness of four alloys depends on the difference between Md and Mεs, TN temperatures and the stacking fault energy of the parent phase. It is practically meaningful that a quite high net recovery strain can be obtained in Alloys 2 and 4 by the addition of the rare earth Cerium and Nitrogen elements when pre-strained at 300 and 77 K, respectively. The net recovery strain is 4.3% in Alloy 2 and 4.6% in Alloy 4, respectively, at pre-strain 5.3%.