FeMnSiCrNi形状记忆合金中应力诱发ε马氏体逆相变的TEM研究

TEM study on stress induced ε martensitic reverse transformation in FeMnSiCrNi shape memory alloys

利用透射电镜观察了Fe 1 8Mn 5Si 1 0Cr 4Ni记忆合金中应力诱发ε马氏体在逆相变过程中的微观组织变化 ,对ε→γ逆相变进行了研究 在应力诱发γ→ε马氏体相变过程中 ,形成了两种不同形态的ε马氏体 ,它们的逆相变表现出不同的特征 对于单片状ε马氏体 ,逆相变的进行较容易 ,且易实现晶体学完全可逆 ;对于由多层组成的宽ε马氏体带 ,逆相变较困难 。

TEM observations were carried out on the microstructural changes of stress induced ε martensitie during the ε→γ reverse transformation in FeMnSiCrNi shape memory alloys,and based on these experimental observations the ε→γ reverse transformation was investigated.Two kinds of ε martensite were obtained during the stress induced γ→ε transformation:one is single plate like ε martensite and the other is the wide ε matrensite band interspersed with thin γ layers.These two kinds of ε martensite show different features in the process of ε→γ reverse transformation.The reversion of the single plate like ε martensite can take place easily and reach complete crystallographic reversibility;but the case for the wide ε martensite band is to the contrary .