摘要
利用电阻法、低温动态电子显微术和低温动态X射线衍射法研究了FeNiCoTi合金不同时间时效处理对马氏体相变和形貌的影响。结果表明,合金经过953K×3h时效处理后硬度最高,达535HV,在低温下发生马氏体可逆相变而生成具有热弹性的薄片状马氏体,具有良好的形状记忆效应。延长时效时间,硬度逐渐降低,相变点升高,低温下发生不完全马氏体可逆相变,除薄片状马氏体外,还生成部分非热弹性的断续状马氏体。当时效时间超过25h 后,合金在低温下发生完全不可逆的马氏体相变而生成透镜状马氏体。
The influence of ausaging with different time on martensitictransformation and its morpholgy of FeNiCoTi alloy has been investigated us-ing electrical resistance method,transmission electron microscopy and X-raydiffraction with cryogenic dynamic.It has been found that the highest hard-ness of this alloy amounted to 535HV with 3h ansaging at 953K,the reversalmartensitic transformation took place at low temperature and the thin platemartensites with thermal-elasticity existed,thus the fine shape memory effectis appeared.Increasing the ausaging time,the hardness is reduced and the transformation points(Ms,As)are increased gradually,uncompleted revarsalmartensitic transformation take place at the low temperature,and some intermittent martensites with no thermal-elasticity are found besides the thinplate martensites.The non-reversal martensitic transformation takes place atthe low temperature and the lenticular martensites are found if the ausagingtime is more than 25h.
关键词
形状记忆合金
时效
马氏体转变
ausaging
γ′(Ni Ti)particulates
martensitic transformation
