Hardness, yield strength, and plastic flow in thin film metallic-glass

Abstract

Thin film metallic-glasses (TFMGs) are a promising structural material for fabricating the next generation of micro- and nano-devices; however, a comprehensive study is still lacking today for understanding their mechanical behaviors. In this article, we present a systematic study on the Zr53Cu29Al12Ni6 TFMGs with varying thicknesses. Other than the intrinsic factor of structural amorphousness, our study pinpoints other extrinsic variables that could affect the hardness and yield strength of the TFMGs. Furthermore, the experimental results from microcompression show that the plastic flow in the TFMG-based micropillars exhibit strong sample size-and-shape dependence, which manifests as a smooth plastic deformation transition from the inhomogeneous to homogeneous mode when the TFMG-based micropillars with a submicron-scale film thickness are deformed into the shape of a low aspect ratio.