The Preparation Of The Near Or Same Atomic Proportion TiNi Alloy Thin Film And The Study Of Martensitic Shape Transformation Mechanics

The paper mainly study the preparation process of the near or same atomic proportion TiNi alloy thin film and the shape transformation of TiNi alloy thin film at dynamic heating and cooling condition,disclosure the transmutation process of TiNi alloy thin film from austenite to martensite.Through preparing the TiNi alloy target,making the TiNi alloy thin film by magnetron sputtering,crystallizing the TiNi thin film,observing the microstructure and pattern of TiNi alloy thin film by modern analysing method for example X-Ray Diffraction instrument,Transmission electron microscope and Scanning electronic microscope and so on,surveying the process of shape transformation at dynamic heating and cooling condition,we draw the conclusions as following:1.When we prepare the TiNi alloy thin film by magnetron sputtering,the main influencing factor in their given order is electric current(power),working air pressure and the distance of target.This time the TiNi alloy thin film is amorphous,but part of the thin film has been crystallized.2.Through experiment,the optimally parameter of preparing the TiNi alloy thin film bymagnetron:the electric current is 0.7A, working air pressure is 0.6Pa, the distance of target is 55mm.3.When we crystallize the TiNi alloy thin film,the temperature is about 600℃,the annealing time is 1 hour.This time the thin film is complete crystallizing,but the same time precipitated phase(TiNi3) is created.4.Through heating and cooling the TiNi alloy thin film at dynamic condition,we find that the TiNi alloy thin film existences with R phase and little martensite phase at room-temperature, existences with austenite phase at high temperature.5.When TiNi alloy thin film is heated from room-temperature to 70℃,it existences with austenite phase;when TiNi alloy thin film is cooled to room-temperature even low temperature,it existences with R phase and martensite phase。6. The shape transformation of TiNi alloy thin film is not direct from martensite to austenite,the similar to TiNi alloy,its heating phase transformation order is : martensite phase→R phase→austenite; its cooling phase transformation order is: austenite→R phase→martensite phase.7.Through calibrating with the electron diffraction pattern,the orientation of B2 and R phase is: [001]B2∥[1-1-1]R,(110)B2∥[101]R.