A transition from localized shear banding to homogeneous superplastic flow in nanoglass

A promising remedy to the failure of metallic glasses (MGs) by shear banding is the use of a dense network of glass-glass interfaces, i.e., a nanoglass (NG). Here we investigate the effect of grain size (d) on the failure of NG by performing molecular dynamics simulations of tensile-loading on Cu50Zr50 NG with d = to 15 nm. Our results reveal a drastic change in deformation mode from a single shear band (d similar to 15 to 10 nm), to cooperative shear failure (d similar to 10 to 5 nm), to homogeneous superplastic flow (d <= 5 nm). Our results suggest that grain size can be an effective design parameter to tune the mechanical properties of MGs. (C) 2013 AIP Publishing LLC.