Discrete shear band plasticity through dislocation activities in body-centered cubic tungsten nanowires.

ABSTRACT: Shear band in metallic crystals is localized deformation with high dislocation density, which is often observed in nanopillar deformation experiments. The shear band dynamics coupled with dislocation activities, however, remains unclear. Here, we investigate the dynamic processes of dislocation and shear band in body-centered cubic (BCC) tungsten nanowires via an integrated approach of in situ nanomechanical testing and atomistic simulation. We find a strong effect of surface orientation on dislocation nucleation in tungsten nanowires, in which {111} surfaces act as favorite sites under high strain. While dislocation activities in a localized region give rise to an initially thin shear band, self-catalyzed stress concentration and dislocation nucleation at shear band interfaces cause a dis

SUBMITTER: Wang J 

PROVIDER: S-EPMC5854623 | biostudies-literature | 2018 Mar

REPOSITORIES: biostudies-literature