Study On Preparation Process Of TiNi And TiNiCu Memory Alloy Films On Optical Fiber Substrate

In recent years,miniaturized,intelligent,integrated and cost-effective MEMS has received extensive attention.TiNi-based shape memory alloy thin films have good shape memory effect,superelasticity,corrosion resistance and biocompatibility.The phase transition of TiNi-based shape memory alloy thin films is accompanied by significant changes in mechanical,physical and chemical properties,such as yield stress,elastic modulus,hardness,resistivity,thermal expansion coefficient and surface roughness.The optical devices developed can be used as microsensors.This kind of film also has the characteristics of high sensitivity,large driving force and large displacement,which can be used as driving material for MEMS.The optical fiber device covered with TiNi-based memory alloy film is expected to achieve remote controllable driving function,and the developed MEMS has important application value in deep-sea exploration,biomedicine and other fields.Different from the traditional planar substrate,the fiber surface is a cylindrical surface with small diameter.How to prepare TiNi-based memory alloy films with good quality on itneeds to be explored.In this paper,the process of preparing TiNi and TiNiCu memory alloy films on the fiber substrate by magnetron sputtering was mainly studied.The effects of sputtering process parameters and subsequent annealing treatment on the quality of films were systematically discussed,and the related processes were optimized.The specific research contents are as follows:(1)Develop a standard film preparation process.Aiming at the problem that the selected optical fiber substrate is a cylindrical surface,which is different from the traditional planar substrate and the coating operation is difficult,a special optical fiber coating mask device is designed to prepare a uniform film on the circumferential surface of the optical fiber substrate.The characterization methods of thin films are introduced.(2)The effects of different preparation parameters on the preparation of optical fiber substrate films were studied.The thickness of the film was measured by a bench tester,and the surface morphology of the film was analyzed by an atomic force microscope.The effects of sputtering power,sputtering pressure and sputtering time on the deposition rate,thickness and surface morphology of the film were discussed in detail.On this basis,the optimal preparation process parameters were determined.(3)The annealing characteristics of the films were studied,and the composition and phase structure of the films prepared under different experimental conditions were discussed.The composition of the films was analyzed by X-ray energy spectrometer,and the phase structure of the films after sputtering and annealing was analyzed by X-ray diffraction.The effects of sputtering power and annealing temperature on the composition,surface morphology and phase structure of the films were explored.