Compromising high strength and ductility in nanoglass–metallic glass nanolaminates

Abstract

We use large-scale molecular-dynamics simulations to investigate the deformation and failure mechanisms associated with tensile loading of 50 nm diameter Cu₆₄Zr₃₆ nanolaminate nanopillars constructed either as 5 nm thick layers of metallic glass (MG) or alternating 5 nm thick layers of MG and 5 nm grain sized nanoglass (NG). The MG–MG nanolaminate exhibits delayed shear band formation and diffused shear banding failure while the NG–MG nanolaminate shows exceptional plasticity to a strain of ε = 0.15 prior to a necking-type failure. The MG–MG nanopillar has approximately the same restricted ductility and ∼15% lower strength than a reference MG nanopillar. The NG–MG nanopillar, on the other hand, retains the same level of ductility but displays ∼20% higher strength than a reference NG nanopillar. These results suggest that nanolaminates of NG and MG offer promise for creating structures that combine outstanding strength and ductility.