【作者】 钱士强；

【导师】 吴建生；

【作者基本信息】 上海交通大学 ， 材料学， 2006， 博士

【摘要】 TiNiPd高温形状记忆薄膜的研究对于工作温度处于100℃～200℃的微电子机械系统(MEMS)有着重要的意义。本文的工作着眼于TiNiPd形状记忆薄膜的应用基础性研究,使用差示扫描量热计(DSC)、动态热机械分析仪(DMA)、X射线衍射仪(XRD)、透射电子显微镜(TEM)以及磁控溅射仪,薄膜拉伸台、形状记忆应变弯曲装置等设备,从薄膜的制备、处理加工、晶化和氧化特性、形状记忆特性、相变组织、拉伸及内耗性能等诸方面对TiNiPd高温形状记忆薄膜进行了系统深入的研究。利用合金靶磁控溅射技术辅助加补小Ti片成功制备了具有预定成分的大片TiNiPd自由薄膜。研究表明,TiNiPd薄膜的成分控制规律与TiNi薄膜的有很大区别,相比靶材的成分,薄膜中Pd量明显减少而Ni量大大增加,Ti量的变化不大。添加Ti片可增加薄膜中的Ti量,但同时Ni量下降,而Pd量变化不大。研究发现溅射功率影响薄膜中三组元的比例。溅射薄膜中的Ti含量随溅射功率增大明显减小,但Ni和Pd的含量略有上升。基片类型也影响溅射薄膜的成分。TiNiPd薄膜的溅射态为非晶态结构,其原子排列比TiNi的要松散。晶化温度的研究表明自由薄膜的晶化温度与基片类型关系不大,但与成分有关,Ti含量增加或Pd含量减少都使晶化温度升高。Ti的作用比Pd的更强。自由薄膜的晶化温度基本在480℃～510℃,粘附于基片的薄膜则要高30℃～50℃。晶化前低于晶化温度的预处理对晶化温度影响不大。实验发现TiNiPd薄膜相比TiNi薄膜更易氧化,其短时氧化特性符合线性-抛物线规律。非晶态薄膜的氧化激活能比TiO2的略低,晶态薄膜的则不到其半值,这是TiNiPd薄膜易氧化的一个原因。研究表明TiNiPd薄膜中的Pd原子促进O原子和Ti原子结合,排斥氧化界面处氧化物中的Ti原子,导致薄膜中的Ti原子通过氧化界面向外扩散。这是TiNiPd薄膜易氧化的主要原因。着重研究考察了Ti51.5Ni26.0Pd22.5薄膜的相变,经550℃1h或750℃1h或750℃1h+450℃1h处理的薄膜试样在室温以上温度有马氏体相变和逆相变。经750℃1h晶化处理的薄膜相变温度较高,在冷却过程中显现B2→B19一步相变。经550℃1h晶化处理的薄膜相变温度低,且有多次转变,但都是B2→B19一步相变。更多还原

【Abstract】 The research of TiNiPd high temperature shape memory films is important for Micro-Electro-Mechanical Systems (MEMS) working at 100oC~200oC. As an applying fundamental research, in this paper the TiNiPd shape memory films were studied with the emphases on the fabrication and treating technology, crystallizing and oxidizing characteristic, shape memory effect, phase transformation and microstructure, tensile performance and internal friction etc. using DSC, DMA, XRD, TEM, magnetron sputtering, film tensile test, curvature strain measuring and so on.Firstly, TiNiPd films’fabrication and their component control were investigated. Large pieces TiNiPd films with preconcert composition were made by the magnetron sputtering using alloy target with Ti foils. The results show that comparing with the composition of the target, in the film the Pd content decreases and Ni content increases distinctly but Ti content changes not so. With Ti foils on the alloy target Ti content increases at the correspond area on film while Ni content decreases but Pd content changes little.It was found that the substrate property and sputtering power affected the composition of films. There is variant composition on deferent substrate at same sputtering condition. When increasing sputtering power the Ti content in sputtering films decreases markedly while Ni and Pd content increases a little. The sputtering TiNiPd films are amorphous structure and the atom arrangement in it is looser than that in TiNi films.The study about crystallizing point of TiNiPd sputtering films shows that the crystallizing point of free films is more relate to composition of the films but a little to the type of substrate. The increase of Ti content and the decrease of Pd content in TiNiPd films would lead to high crystallizing point of the films, in which the effect of Ti is larger than that of Pd. The crystallizing point of free TiNiPd films is at about 480oC ~510oC and lower 30oC~50oC than that of the films adhering to substrate. The更多还原