Metallic nanowires (NWs) display superior mechanical properties compared to their bulk counterparts and are regarded as promising building blocks for flexible and transparent electronic devices due to their high conductivity. Most fcc-metallic NWs are oriented along a <110> axis, and many NWs have one or multiple twin boundaries (TBs) parallel to the wire axis. Such NWs have been studied extensively in tension, where the TBs were shown to lead to an increase in yield stress and to a different deformation morphology compared to single crystalline NWs. The influence of TBs on the deformation in bending, most important for applications in flexible electronics, has, however, so far not been studied in detail.

Here we present our recent results of molecular dynamics simulations on single crystalline NWs (SCNW) and bi-crystalline twinned NWs (BTNW) subjected to bending. Atomistic simulations allow for controlled variation of NW composition, size, morphology, as well as the location of twin boundaries (TBs) and the loading condition. We show that the presence of a TB not only influences the plastic deformation but also affects the stress state of nanowires. The critical resolved shear stress for dislocation nucleation was determined and the interactions of dislocations with TBs was studied in detail for varying TB location and bending directions.