Thermal effects on the mechanical behavior of CuZr metallic glasses

Abstract

Amorphous metals are increasingly used as advanced engineering materials, due to several desirable properties, like high hardness and ductility, high resilience, high mechanical strength and high wear resistance, among others. However, many details of the mechanical behavior of amorphous metals are still unknown, and currently used models and theories are far from predictive. Here we use atomistic molecular dynamics (MD) simulations to study the mechanical behavior of an amorphous Cu46Zr54 sample, focusing on temperature effects on the tension-compression asymmetry. We find a large tension-compression asymmetry in plastic yielding, and an expected softening of the material as temperature is increased. We observe the formation of shear bands and, under tension, void nucleation leads to significant stress relaxation. The behavior of icosahedra-like polyhedra versus strain correlates with the onset of plastic behavior. The temperature-dependent softening response follows a T2∕3-relationship as discussed in previous studies.