Influence of slip transmission on the migration of incoherent twin boundaries in epitaxial nanotwinned Cu

Using in situ nanoindentation, we studied the migration mechanisms of Σ3{1 1 2} incoherent twin boundary (ITB) in epitaxial nanotwinned Cu films. ITBs migrate by propagation of steps or disconnections with step heights of three or multiples of three {1 1 1} interplanar distances, and the migration may lead to the detwinning of nanotwins. The transmission of a glide dislocation across an ITB is shown to form a sessile dislocation in the ITB and locally pin the boundary at the site of the slip transmission.