In situ atomistic mechanisms of detwinning in nanocrystalline AuAg alloy

Detwinning is an important plastic deformation mechanism that can significantly affect the mechanical properties of twin-structured metals. Although many detwinning mechanisms have been proposed for pure metals, it unclear whether such a model valid nanocrystalline alloys because lack direct evidence. Here, atomicscale process AuAg alloy with average grain size ∼15 nm was investigated in situ. The results show there are three types alloys. first type from boundary migration. second occurs through combined layer-by-layer thinning and incoherent twin last one migration, which collective motion partial dislocations array.