Multiple and extended shear band formation in MgCuGd metallic glass during high-pressure torsion

Mg 65 Cu 25 Gd 10 bulk metallic glass (BMG), containing a high density of intersecting extended shear bands (SBs), was fabricated from densification of amorphous powder via high-pressure torsion (HPT). The extended SBs, up to 400 nm in width and containing nanocrystalline structures, were studied by electron microscopy. The mechanisms responsible for the formation of the high density of extended SBs are discussed and related to the high hydrostatic pressure and shear strains imposed during HPT of BMGs.