(北京航空航天大學(xué) 材料科學(xué)與工程系，北京 100083)
摘 要: 采用原位水熱化學(xué)合成法，在TiNi形狀記憶合金表面制備了組成主要為TiO2的絕緣膜，并對(duì)此絕緣膜的生長過程、 形貌以及相結(jié)構(gòu)等進(jìn)行了研究。結(jié)果表明，該絕緣膜主要成分為Ti和O，其相組成為TiO2和TiO2-x(x≤0.2)。隨著絕緣膜保溫時(shí)間的延長，絕緣膜逐漸增厚，可以達(dá)到4～5μm。適宜的保溫溫度約為200℃，保溫時(shí)間為8～12h。當(dāng)保溫時(shí)間超過16h時(shí)，絕緣膜開始產(chǎn)生裂紋。對(duì)絕緣膜電阻特性的測試結(jié)果表明：絕緣膜電阻隨保溫時(shí)間增加而增大，在200℃保溫12h后的絕緣膜電阻最大，其值為8.33×105Ω。
關(guān)鍵字: 記憶合金； 絕緣膜； 生長過程； 相結(jié)構(gòu)
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
