Investigation on mechanical properties of sputtered TiNi thin films

Abstract

The TiNi thin films are deposited onto glass substrates by magnetron sputtering. The film composition is determined to be Ti-51.06 at.% Ni by energy dispersive X-ray spectroscopy (EDX). The as-deposited films are annealed under different conditions. There are Ti3Ni4 and TiNi3 precipitates in the annealed films. With the increase of annealed temperature, the martensite transformation temperature is increase, which is induced by Ni-rich precipitates emergence. The mechanical properties are studied by MTS IIXP Nano-Hardness Tester. The nano-hardness and elastic modulus are related with annealing conditions. Ti3Ni4 phase emergence and decomposing in the stage of annealing from 525 to 600 °C. Following decreasing primarily nano-hardness and elastic modulus increase steadily. That is attributed to the precipitation hardness induced by Ti3Ni4 and TiNi3 phase. The precipitates might influence mechanical properties of thin films. © 2010 Elsevier B.V. All rights reserved.