Non-localized deformation in Cu Zr multi-layer amorphous films under tension

In metallic glasses (MGs), plastic deformation at room temperature is dominated by highly localized shear bands. Here we report the non-localized deformation under tension in Cu Zr multi-layer MGs with a pure amorphous structure using large-scale atomistic simulations. It is demonstrated that amorphous samples with high layer numbers, composed of Cu64Zr36 and Cu40Zr60, or Cu64Zr36 and Cu50Zr50, present obviously non-localized deformation behavior. We reveal that the deformation behavior of the multi-layer-structured MG films is related but not determined by the deformation behavior of the composed individual layers. The criterion for the deformation mode change for MGs with a pure amorphous structure, in generally, was suggested, i.e., the competition between the elastic-energy density stored and the energy density needed for forming one mature shear band in MGs. Our results provide a promising strategy for designing tensile ductile MGs with a pure amorphous structure at room temperature.