Dynamic recrystallization in Cu-Si bicrystals

The grain-boundary dependent occurrence of dynamic recrystallization was systematically studied by using orientation-controlled Cu-Si bicrystals. The bicrystals having several [001] twist boundaries were hot-deformed in tension at a temperature 1023K and a strain rate of 4.17x10(-4)s(-1), followed by H-2 gas quenching. The specimens deformed were (crystallographically) observed using transmission electron microscope and optical microscope. As grain-boundary energy increases, dynamic recrystallization took place easier at grain boundary at lower strain. This grain-boundary dependent characteristic of dynamic recrystallization was closely attributable to the difference in the occurrence of grain-boundary sliding, grain-boundary migration, grain-boundary serration and piling-up of dislocations to grain boundary followed by the development of inhomogeneous dislocation substructures nearby grain boundary.