Orientation effect of pre-introduced shear bands in a bulk-metallic glass on its “work-ductilising”

By means of the constrained compression with small specimen aspect ratios, an intrinsically brittle Zr52.5Cu17.9Ni14.6Al10Ti5 bulk-metallic glass (BMG) was plastically deformed to various extents (up to 46%) at room temperature. The “work-ductilising” behavior of the deformed BMG was investigated under the subsequent compression with a normal specimen aspect ratio of 2. The plasticity after pre-plastic deformation was related to the spatial distribution of pre-introduced shear bands. It is found that the ductilisation of the BMG by pre-introduced shear bands depends upon their orientations, only the pre-introduced shear bands with the orientation close to the direction of maximum shear stress can effectively ductilise the BMG. The orientation effect of pre-introduced shear bands in the BMG on its “work-ductilising” indicates the way to further improve the plasticity of BMGs by pre-plastic deformation.