Effect of grain size on amount of deformation-induced epsilon martensite and shape memory effect in Fe-Mn Alloy

Abstract

In this work, a new method of measuring volume fraction of epsilon martensite formed both by cooling and deformation using volume change and endothermic heat on epsilon -> gamma transformation, respectively. The variation in the amount of epsilon with grain size is determined for an Fe-21Mn alloy, and its influence on shape memory effect is investigated. As grain size increases, the amount of epsilon martensite forming on cooling increases. However, with a decrease in grain size, more epsilon is induced by deformation, improving shape memory effect.