Previous investigations had shown that twin boundaries in annealed material were a significant source of dislocations in the initial stages of plastic flow. The nature of the dislocation source was unknown, but it was suggested that twin boundaries might be non-regenerative dislocation sources that could cause migration of the boundary during plastic deformation. Channel die deformation and intermittent orientation imaging were performed on split specimens of the pure metal in an attempt to observe twin boundary migration. Some 15% of the twin boundaries were observed to migrate beyond that expected on the basis of the imposed strain. The data supported the hypothesis that twin boundaries could serve as dislocation sources.

Observation of Twin Boundary Migration in Copper during Deformation. D.P.Field, B.W.True, T.M.Lillo, J.E.Flinn: Materials Science and Engineering A, 2004, 372[1-2], 173-9