Loading-direction-dependent bending anisotropy of a BCC molybdenum nanowire: a molecular dynamics study

This study employs molecular dynamics simulations to investigate the bending behavior and the underlying deformation mechanisms in a ⟨110⟩-oriented body-centered cubic Mo nanowire, with particular focus on the influence of loading directions. The results demonstrate a significant bending anisotropy in deformation mechanism, where deformation twinning dominates the [001]-bending, whereas dislocation slip prevails in [110]-bending. The different deformation modes are also manifested by the distinctive mechanical response of the nanowires. Based on the geometrical constraints of bending, surface energy is identified as the key factor governing the deformation mode selection. Unloading tests reveal complete shape recovery for both loading directions, which occurs by detwinning in [001]-bending and dislocation retraction in [110]-bending. These findings provide fundamental insights into nanoscale bending plasticity and recovery behavior in BCC nanowires, with significant implications for design of flexible and stretchable nanodevices.