Plastic heterogeneity in nanoscale metallic glass

Elongation of CuZr metallic amorphous nanorods at a low strain rate has been examined by molecular dynamics methods. Results indicate that nanoscale metallic glasses (NMGs) show non-brittle fracture and plastic heterogeneity. In addition, the size effect has been carefully investigated via the NMG samples with different diameters. Meanwhile, the fluctuation of the stress and structure during the elongation provides reliable evidences to explain why plastic heterogeneity exists in the NMGs. Our results suggest that the mechanical properties of NMGs would be closely related to the size effect and heterogeneity in NMG samples.

Graphical AbstractThe selected cross section in the Cu50Zr50 NMG sample during plastic deformation is shown, which reflects the heterogeneity in energy distribution. The color bars are for the contour plots of the total potential energy.Figure optionsDownload as PowerPoint slideHighlights
► CuZr NMGs with high strength of 1.6 GPa can simultaneously present promising ductility of ∼60%.
► Neither brittle fracture nor shear band is observed.
► Mechanical properties of metallic glasses in the nanoscale depend on the stress concentration.