Chemical stresses induced by grain-boundary diffusion

[[abstract]]Based on Whipple-Suzuoka solutions, the chemical stresses induced by grain-boundary diffusion under constant- and instantaneous-source concentrations are investigated. For a finite boundary, the chemical stress consists of both compression and tension fields, in the sequence of compression I-tension-compression II, with the compression I field near the diffusion interface. The magnitudes and distributions of these fields differ for different source concentrations and are strongly affected by the ratio of diffusivity in the grain boundary and diffusivity in the lattice (D'/D). As D'/D increases, the magnitude of the compression I field decreases and that of the tension and compression II fields increases. An increase in D'/D also increases the range of the compression I field. The trend is distinct in the case of constant-source diffusion, while in the case of instantaneous source diffusion, both the tension and compression II fields appear to be extremely small.[[fileno]]2020330010025[[department]]材料