热机械训练过程中Fe-Mn-Si系形状记忆合金的组织演变

Microstructure Evolution of Fe-Mn-Si Shape Memory Alloy During Thermal Mechanical Training Process

采用金相、XRD、SEM和TEM等对Fe-Mn-Si系形状记忆合金在热机械训练过程中组织的演变进行研究。结果表明:热机械训练是应力诱发γ→ε马氏体相变及其逆相变过程的重复。训练前的组织中几乎不存在马氏体,训练后合金中应力诱发的ε马氏体分布比较均匀,相互平行,交叉现象较少。同时,晶体中的马氏体呈现ε马氏体区域择优取向,过多(5次以上)训练后,合金基体内部形成大量位错缠结。

The microstructure evolution of Fe-Mn-Si shape memory alloy in the process of thermal mechanical training was studied through analysis by microscopy,XRD,SEM and TEM.The results show that thermal mechanical training is a repeated transformation process of stress inducedγ→εmartensite and its reverse.Before the training,few martensites are observed in the structure.After the training,εmartensites distribute uniformly,in parallel with each other,and less crossover phenomenons.Meanwhile,martensites in crystal structure with martensitic prefer zone orientation.After a lot of training（over five times）,a lot of dislocation tangle is formed inside the alloy matrix.