In order to study the interaction of persistent slip bands with grain boundaries, a specially designed [¯134]/[18¯27] bicrystal with an inclined grain boundary and a common primary slip plane in its component crystals was prepared. The dislocation patterns within grains, and near to the grain boundary, in bicrystals which had been cyclically deformed at an axial plastic-strain amplitude of 9 x 10-4 were observed by using the electron channelling contrast scanning electron microscopy technique. The results showed that the surface slip bands could pass through the grain boundary continuously and did not induce any secondary slip near to the grain boundary. The ladder-like persistent slip band structures could form in both the [¯134] and [18¯27] component crystals. On one surface, the ladder-like persistent slip bands were still continuous beside the grain boundary. However, the dislocation arrangements in the persistent slip bands beside the grain boundary became irregular and discontinuous on another surface. On the common primary slip (111) plane, a dislocation-affected zone with a width of 5 to 10µ was observed on one side of the grain boundary. The observations revealed that the dislocation structures within the surface slip bands passing through the grain boundary were not completely continuous during cyclic deformation, even though the 2 grains had a common (111) primary slip plane.

Observations of Persistent Slip Bands Transferring through a Grain Boundary in a Copper Bicrystal by the Electron Channelling Contrast in Scanning Electron Microscopy. Z.F.Zhang, Z.G.Wang, H.H.Su: Philosophical Magazine Letters, 1999, 79[5], 233-40