Sliding behaviour of symmetric tilt near ∑=25{12̄16} boundary in zinc bicrystals

The sliding behaviour of a 67°〈101̄0〉 symmetric tilt boundary close to a special boundary with ∑=25{12̄16}, was investigated in zinc bicrystals. The bicrystals were creep tested at two values of tensile stress. Grain boundary sliding (GBS) accompanying migration in a fixed ratio occurred in both bicrystals. The value of the migration is ≈5 times that of the GBS itself. For the bicrystal tested at a lower stress, the value of the uniform distribution of GBS and migration along the boundary was observed. At the same time, when the bicrystal was tested at the higher stress level, the sliding and migration values gradually increased from one end of the boundary to the other one. The average ratio between GBS and boundary migration was practically independent of the stress value. These effects are interpreted in terms of the behaviour of DSC-dislocations generated by grain boundary dislocation sources, and produced as a result of the interaction between lattice dislocations and the grain boundary.