Deformation behavior of Zr-based bulk metallic glass and composite in the supercooled liquid region

A Zr-based bulk metallic glass (BMG) with a composition of (Zr75Cu25)78.5Ta4Ni10Al7.5and a bulk metallic glass matrix composite (BMGC) with a composition of (Zr75Cu25)74.5Ta8Ni10Al7.5have been prepared by copper-mold casting. The compressive deformation behavior of the BMG and BMGC was investigated in the supercooled region at different temperatures and various strain rates ranging from 8×10-4s-1to 8×10-2s-1. It was found that both the strain rate and test temperature significantly affect the deformation behavior of the two alloys. The deformation follows Newtonian flow at low strain rates but non-Newtonian flow at high strain rates. The deformation mechanism for the two kinds of alloys was discussed in terms of the transition state theory.