STRESS-RELAXATION BY PLASTIC-FLOW, INTERFACIAL SLIDING AND DIFFUSION IN AN INCLUSION BEARING MATERIAL

Stress relaxation, a decrease of energy by plastic flow, interfacial s liding, local diffusion and bulk diffusion, has been studied for an in clusion bearing material. The complete relaxed state is found by minim izing the total energy, using a variational method. A relaxation proce ss or the combination of two processes imposes a subsidiary condition that matches the physics of the process. The complete relaxation occur s when total stresses are uniformly hydrostatic in a plastic region. I n interface-related phenomena, the complete relaxed stale is as follow s: tangential traction vanishes for interfacial sliding; normal tracti on is constant for local diffusion; and total traction is constant and normal to the interface for the combination of interfacial sliding an d diffusion. When bulk diffusion is allowed, normal traction vanishes. If sliding is further allowed, an inclusion becomes stress free. By e xamining subsidiary conditions, the effectiveness of two processes can be compared. Copyright (C) 1997 Acta Metallurgica Inc.