The occurrence of diffusion-induced grain boundary migration, when Ag diffused along the grain boundaries of Cu, was confirmed by characterizing the microstructures and the morphologies of migrated boundaries, the discontinuous and asymmetric character of the concentration profile, the dislocation configuration, and the kinetics of migration. The experimental results revealed that bulging and faceting were 2 basic modes of diffusion-induced boundary migration. The incubation period for the process was different for different boundaries. The area of diffusion-induced migration obeyed a fifth-root time dependence. The rate of migration was quicker at the beginning, and then slowed down. A particular type of dislocation configuration appeared at points which were adjacent to the original position of the boundary. The migration rate obeyed an Arrhenius relationship, with an activation energy of about 62kJ/mol. Solubility was not the main factor which controlled the migration kinetics. The diffusivity which was associated with the migrating boundary was 3 orders of magnitude higher than that for a stationary boundary.

Z.Guan, G.Liu, J.Du: Acta Metallurgica et Materialia, 1993, 41[4], 1293-300