Observation of twin boundary migration in copper during deformation

A previous investigation produced evidence that twin boundaries in annealed copper were a significant source of dislocations during the initial stages of plastic flow. The character of the dislocation source was unknown, but it was hypothesized that twin boundaries could be non-regenerative dislocation sources that would cause migration of the boundary during plastic deformation. Channel die deformation and intermittent orientation imaging were performed on split specimens of pure copper in an attempt to observe twin boundary migration. Approximately 15% of the twin boundaries were observed to migrate beyond that expected from the imposed strain. The data support the hypothesis that twin boundaries can serve as dislocation sources.