BSTRACTThe 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.