Avalanches in Cu-Zr-Al metallic glasses.

Abstract

Metallic glasses have mechanical properties, which exhibit avalanches in the disguise of stress drops. We study these phenomena in a classical metallic glass system Cu-Zr-Al by athermal quasistatic shear and varying the element concentrations and for pure Cu-Zr 50/50 case the cooling rate. The resulting mechanical properties are close to the behavior found experimentally. At small strains, the pristine systems are akin to other glassy systems with a so-called gap distribution with a small positive exponent. Critical avalanching behavior is found only approaching the yield point. The post-yield stress drops are universal, and the gap distribution becomes flat.