The misorientation dependence of grain boundary sliding and effects of grain boundary structure and crystal deformation on sliding have been studied by experiments using ⟨1010⟩ tilt zinc bicrystals with different misorientations. The results have shown that grain boundary sliding strongly depends on the misorientation and is difficult in exact- or slightly off-coincidence boundaries. A cusp found near a tilt angle of 55° is explained by the existence of a 56·6°⟨1010⟩/⟩/Σ9 near-coincidence boundary. The observations are interpreted on a dislocation mechanism for sliding which is based on the movement of crystal lattice dislocations along the grain boundary by a combination of climb and glide. © 1979 Taylor & Francis Group, LLC.
