Grain and grain boundary zone contributions to strain accumulation during creep of polycrystalline copper

Variations in the shapes of the creep curves recorded for pure copper are studied after prestraining at room temperature and at the creep temperature of 686 K. Under the imposed stress/temperature conditions, dislocation processes govern the deformation rates, while grain boundary cavity development leads to intergranular failure. The results indicate the differing contributions of the grain interiors and grain boundary zones to the changing patterns of strain accumulation and damage evolution throughout the creep life.