Deformation behavior of a TiZr-based metallic glass composite containing dendrites in the supercooled liquid region

Abstract

The deformation behavior of a TiZr-based bulk metallic glass composite (BMGC) was characterized in the supercooled liquid region (SLR) from 623 K to 693 K. It was observed that the alloy exhibits the deformation behavior from work softening at low temperatures to work hardening at high temperatures. The yield stress and overshoot stress decrease remarkably with the increase of temperature, accompanied by superplasticity. The results showed that the crystallization occurred in the amorphous matrix for the post-deformation samples and the volume fraction of the corresponding crystallization products increased with increasing testing temperature. It is implied that the work hardening behavior was closely associated with the crystallization of the amorphous matrix. The tensile stress can accelerate the crystallization of amorphous matrix and the martensitic transformation of dendrite phases, which implies that the thermal stability of the alloy decreases under tension. These findings shed light on designing new BMGCs with high mechanical performance as well as the good SLR formability.