It was noted that the occurrence of deformation twinning in face-centered cubic crystals with medium to high stacking fault energy was normally very difficult. By specially choosing the orientation of a Cu single crystal, it was here not only found possible to observe profuse nanoscale deformation twins with a tower shape, originating from the grain boundary, but it was also found that some of them terminated within the interior of the grain. The observations clearly proved that the deformation twinning could nucleate via successive emission of partials from grain boundaries, indicating the ubiquity of deformation twinning even in those face-centred cubic single crystals deformed under suitable conditions.

Origin of Deformation Twinning from Grain Boundary in Copper. W.Z.Han, S.D.Wu, S.X.Li, Z.F.Zhang: Applied Physics Letters, 2008, 92[22], 221909