Nanoindentation response of an ion irradiated Zr-based bulk metallic glass

Abstract

Nanoindentation experiments were conducted on a Ni+ ion-irradiated Zr-based bulk metallic glass (BMG). The irradiation was carried out using 2.5, 5, 10 and 15 MeV ions and a flux of ∼1016 ions/cm2. Post mortem imaging of the indents reveals a transition in the deformation mechanism of the irradiated regions from heterogeneous shear banding to homogeneous flow. Additionally, the load–displacement curves exhibit a transition from serrated to continuous flow with increasing severity of irradiation damage. The stress–strain response obtained from micro-pillar compression experiments complements the indentation response exhibiting a decrease in the flow stress and an ‘apparent’ strain hardening at the lowest irradiation damage investigated, which is not observed in the as-cast alloy.