CAVITATION DURING GRAIN BOUNDARY MIGRATION IN STRESSED COPPER.

Microcavities were formed within grain boundary migrated regions during tensile-straining at the intermediate temperatures in copper. Area fraction of the cavitated regions increased with increasing strain to a certain value dependent on tensile temperature and strain rate. The cavitation becomes most remarkable at 773 K and at the strain rate of 4. 2 multiplied by 10** minus **4s** minus **1. Plastic deformation, boundary sliding and boundary migration are important factors for the cavitation. A model in which deformation ledges and bends in sliding and migrating grain boundaries act as nucleation sites of the cavities, was proposed. The cavitation during grain boundary migration seems to lighten the low ductility failure in copper.