Study on Preparation of Ti-Ni Alloy Films by Unbalanced Magnetron Sputtering and Its Mechanical Properties
|School||Taiyuan University of Technology|
|Course||Materials Processing Engineering|
|Keywords||Ti-Ni alloy films Magnetron sputter ion plating Ingredient Structure Mechanical properties|
Since the 20th century, since the 1960s, Ti-Ni shape memory alloy due to good effect to get more and more applications. However, in the past 20 years, the wear resistance of the alloy started to get attention. Ti-Ni thin films used as a material resistant modified layer has recently become a new research direction. For Ti-Ni thin film materials, structure and properties of a strong sensitivity to the ingredients, so it is necessary to in-depth study of Ti-Ni alloy film preparation process to precisely control the film composition. Through the different components of the film microstructure, phase transition temperature, surface morphology and mechanical properties analysis, Ti-Ni thin films can explore the mechanism of tribological behavior problems, analyze the influencing factors, and to provide the basis for its full characteristics. In this paper, closed field unbalanced magnetron sputter ion plating technique to prepare a composition of 45.4at.% Ti, 46.8at.% Ti, 49.7at.% Ti, 51.3at.% Ti and 53.3at.% Ti of Ti- Ni alloy film. And through EDXA, FSEM, AFM and XRD methods to detect the film composition, surface morphology and phase structure section. Meanwhile, the use of DSC and instruments such as nano-indentation test phase transition temperature of the film, micro-hardness and elastic modulus. In addition, the coating composition of 49.7at.% Ti case, the design of three components the gradient of the transition layer film through adhesion automatic scratch tester and ball disc wear test machine device detects the binding strength of the film, the friction coefficient and the wear rate. Based on the test results, Ti-Ni film explores the tribological behavior of the mechanism. Through research and analysis, the main conclusions are: 1. Preparing nearly equal atomic ratio of Ti-Ni alloy films optimum parameters: argon gas flow 30sccm, bias of 60V, TiNi alloy target current of 6A, Ti target current of 3A, the crystallization temperature of 600 ℃. (2) With the increase of percentage of Ti atom, Ti-Ni alloy thin film Ms appear first increased and then stabilized the situation, in nearly equal atomic ratio reaches a maximum; surface roughness decreases and then increases, In the near-atomic ratio reaches a minimum. 3 in the same load, Ti-Ni alloy thin film hardness and elastic modulus first increases and then decreases. Under different loads, the two did not change significantly; With Ti atomic percentage increase, the film's pseudo-elastic recovery rate η first increases and then decreases. 4. Ti-Ni alloy film is smaller than the friction coefficient; films wear rates than an order of magnitude lower substrate, and the film wear track narrower than the base body. In short, Ti-Ni thin films with respect to the substrate improved tribological properties related primarily to its super-elastic, thin-film strain hardening effect of good, hot hardness and anti-fatigue properties may also help improve the wear resistance of the film. In addition, the film composition, phase structure and other factors will affect the film superelasticity.