Bending-induced deformation twinning in body-centered cubic tungsten nanowires

The competition between dislocation slip and deformation twinning in body-centered cubic (BCC) nanocrystals can be strongly influenced by the deformation conditions. In this study, we investigate the deformation of [112]-oriented BCC tungsten nanowires under different loading modes. It shows that dislocation plasticity is a predominant deformation mode under uniaxial tension, while deformation twinning prevails when non-uniaxial stress is applied. The interfaces of bending-induced twinning are composed of numerous stepwise {112} twin boundaries. These findings shed light on the deformation mechanism of BCC nanocrystals under complex loading conditions. [GRAPHICS] . IMPACT STATEMENTIn situ nanomechanical testing and quantitative analysis reveal a deformation mechanism transition in tungsten nanowires, from dislocation slip under the uniaxial loading to deformation twinning under the non-uniaxial loading.