膜相变点和组织结构的影响
(哈尔滨理工大学 机械动力学院，哈尔滨 150080)
摘 要: 探讨了热处理和热循环对空心阴极离子镀(HCD)法在玻璃基板上制备的Ni-49.12%Ti形状记忆合金薄膜的影响。结果表明，由于镀膜时基板温度较高，所得的膜已部分晶化，其组织为母相组织。经热处理后，其组织发生一系列变化。随加热温度的升高和保温时间的延长，其晶化程度变好，晶粒变粗大，并伴随产生 R 相、马氏体相和Ni3Ti，同时其相变温度也随之有所提高，但是当加热温度过高和保温时间过长，样中各相的量减少，其衍射强度降低。薄膜经热循环后，其相变温度也发生变化。随着热循环次数增加，As和Af点逐渐升高， Ms点有所降低，tR基本保持不变。还发现薄膜经热处理后，其表面晶化程度不及内层。
关键字: 形状记忆合金； 镍钛薄膜； 热处理和热循环
transformation temperature and structure of
Ni-49.12%Ti sputter-depositing film
（College of Mechanical and Power Engineering,
Harbin University of Science and Technology, Harbin 150080, P.R.China）
Abstract:The effects of heat treatment and heat cycle on the SMA thin film of Ni-49.12%Ti formed by hollow cathode deposite(HCD) sputter-deposition on glass substrates were studied. The results showed because the temperature on the substrate is sufficiently high in the process of sputter-depositing film, the thin film is partly crystallized and its organization is the same as the parent phase. A series of change in the film occurs after heat treatment. Within the definite limits, with increasing heat temperature and time, the higher the heat temperature is and the longer the holding time is, the better the crystallizing result will be, and the bigger the crystal size is, meanwhile the productions of R ,M and Ni3Ti phase are accompanied, their transition points are increased. However, when heat temperature is extremely high and holding time is extremely long, the quantity of each phase is reduced and their diffraction intensity is decreased. The temperature of phase transition in thin film after heat cycle is changed. With increasing the number of heat cycle, As and Af increase,Ms decreases and tR keep unchangeable basically. And it is discovered that crystallization in the surface of thin film is not so full as that of its inside after heat treatment.
Key words: shape memory alloy; NiTi thin film; heat treatment and heat cycle
