Effects of Ar ion bombardment by unbalanced magnetron sputtering on mechanical and thermal properties of Ti-Cu-Zr-Ni-Hf-Si thin film metallic glass

Abstract This study investigated the effects of Ar ion bombardment during deposition by unbalanced magnetron sputtering (UBMS) on the structure and mechanical and thermal properties of Ti–Cu–Zr–Ni–Hf–Si thin film metallic glass. It was found that Ar was incorporated into the amorphous structure of the deposited films because of the Ar ion bombardment and that the Ar content in the films could be changed from 0.2 at% to 14.7 at% by controlling the intensity of Ar ion bombardment. The thermal stability of the films was improved by the bombardment process. Further, the surface and cross-sectional morphologies of the films became very smooth and highly dense with an increase in the bombardment intensity. On the other hand, the density of the amorphous structure decreased with the increase in the Ar content. The hardness and Young's modulus also changed with the intensity of Ar ion bombardment. The change in the film hardness was due to the change in the residual stress in the films. Thus, Ar ion bombardment during deposition by UBMS is a useful method for improving the structure and mechanical and thermal properties of thin film metallic glasses.