(北京航空航天大学 材料科学与工程系，北京 100083)
摘 要: 采用原位水热化学合成法，在TiNi形状记忆合金表面制备了组成主要为TiO2的绝缘膜，并对此绝缘膜的生长过程、 形貌以及相结构等进行了研究。结果表明，该绝缘膜主要成分为Ti和O，其相组成为TiO2和TiO2-x(x≤0.2)。随着绝缘膜保温时间的延长，绝缘膜逐渐增厚，可以达到4～5μm。适宜的保温温度约为200℃，保温时间为8～12h。当保温时间超过16h时，绝缘膜开始产生裂纹。对绝缘膜电阻特性的测试结果表明：绝缘膜电阻随保温时间增加而增大，在200℃保温12h后的绝缘膜电阻最大，其值为8.33×105Ω。
关键字: 记忆合金； 绝缘膜； 生长过程； 相结构
insulating films on TiNi shape memory alloys
（Department of Materials Science and Engineering，
Beijing University of Aeronautics and Astronautics，
Beijing 100083, P.R.China）
Abstract:TiO2 insulating films were grown by in-situ hydrothermal chemistry technique. The growth process， morphology and microstructure of the films were investigated systematically. The results show that such films are mainly composed of TiO2 and TiO2-x(x≤0.2), with a maximal thickness of 4～5μm. The optimal fabrication process of this growth technique is found to heat the shape memory alloys with the reaction liquid to 200℃ for 8～12h. Cracks have been found in the films when the holding time exceeded 16h. The resistance increases with the holding time and has a maximum value of about 8.33×105Ω after hold at 200℃ for 12h.
Key words: shape memory alloys; insulating film; growth process; microstructure
