Non-localized deformation in metallic alloys with amorphous structure

In bulk or ribbon metallic alloys with monolithic amorphous structure, plastic deformation at room temperature is dominated by highly localized shear banding. Here we report suppressed shear localization under tension in a metallic glass (MG) embedded with pre-existing amorphous shear bands using large-scale atomistic simulations. It is demonstrated that pre-deformation lowers material strength and triggers enhanced strain fluctuation before sample yielding, leading to highly dispersed plastic shearing in the entire sample. Furthermore, the transition in deformation mode from highly localized shear banding to non-localized plastic deformation is associated with the competition between the yield strength of the material and the critical stress required for the formation of mature shear bands in the load-bearing materials. Given that a sufficient amount of glassy heterogeneities can be introduced into MGs under experimental conditions, the obtained results could provide a promising strategy for designing tensile ductile MGs with pure amorphous structure at room temperature. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved