The characteristics of reversal transformation in Fe-Mn-Si-Cr-Ni shape memory alloys

The transformation characteristics of stress induced $\varepsilon$ martensite with different structure in Fe-17Mn-10Cr-5Si-4Ni alloy has been systematically observed by TEM during heating course, and the reversal transformation of the stress induced $\varepsilon$ martensite has been analyzed simultaneously. It has been found that the reversal transformation is different for the $\varepsilon$ martensite with different structure. For the simple plate $\varepsilon$ martensite, its reversal transformation is of typical thermo-elastic, i.e. $\varepsilon$ martensite disappeared easily through the reversal movement of interface between $\varepsilon$ and $\gamma$, and the crystallographic reversibility is realized at the same time. For the $\varepsilon$ martensite with layered structure, the reversal transformation carried out independently on each layer. As for the wide $\varepsilon$ martensite strap, the reversal transformation is very difficult for its plastic accommodation in different parts, and the transformation hysteresis is very large