Cyclically saturated dislocation patterns within grains and in the vicinity of grain boundaries, in a bi-crystal with a large-angle grain boundary and in a multi-crystal containing small-angle grain boundaries, were observed by using the electron channelling contrast technique of scanning electron microscopy in order to reveal the effect of grain boundaries on cyclic deformation. The results for the multi-crystal showed that dislocation walls and persistent slip bands could pass through small-angle grain boundaries. However, in a bi-crystal with a large-angle grain boundary perpendicular to the stress axis, persistent slip bands could form only within the component grain with a higher Schmid factor, and could not pass through the grain boundary.

Investigations of Dislocation Patterns within Grains and Near Grain Boundaries in Copper by the Electron Channelling Contrast Technique in Scanning Electron Microscopy Z.F.Zhang, Z.G.Wang: Philosophical Magazine Letters, 1998, 78[2], 105-13