TiNi Alloy Deformation At Room-Temperature,Structure And The Sputtered Thin Films

The paper deals with the super-elasticity and compressed deformation-induced martensite at room temperature , indicates the changing trends of the martensite, contrasts the microstructure and properties of two sputtering films ( magnetron sputtering and ion beam sputtering ), confirms the preparation method and the anneal technics, furthermore, observes the martensite at low temperature.The results showed that:(1) Ti-50.7at%Ni alloy has super-elasticity at 4% in tensile test and at 30% in compressed test.(2) Compress can produce deformation-induced martensite . With the increase of value, the martensite increase too. which develop to the applied stress direction, highly deformed, become larger, even intersect, there is also dislocation in the martensite.(3) The films prepared by ion beam sputtering have compact armorphous dumplingmicrostructure surface, then prepared by magnetron sputtering have compact surface with pore and some precipitated phases .(4) The optimum method for preparing TiNi thin films is magnetron sputtering (the parameter is: electrical current 0.6 A, vacuum 0.6 Pa, Ar flux 25 SCCM ). After the nealing of 600℃ for 1 hour, the films can be completely crystallized, which has smooth compact surface with little pore and has Ti2Ni, TiNi3, Ti3Ni4 phase deposited.(5) Deeply cooled can make films produce martensite transformation as follows: B2→R →M, which is the same to the compressed deformation-induced martensite at room temperature.