Chemical stresses which were introduced by grain-boundary diffusion under constant-source and instantaneous-source concentrations were investigated on the basis of Whipple-Suzuoka solutions. In the case of a finite boundary, the chemical stress consisted of both compression and tension fields in the sequence: compression - tension - compression; with the first compression field near to the diffusion interface. The magnitudes and distributions of these fields differed for differing source concentrations, and were strongly affected by the ratio of the diffusivity in the grain boundary to the diffusivity in the lattice. As this ratio increased, the magnitude of the first compression field decreased and that of the tension and second compression fields increased. An increase in the ratio also increased the range of the first compression field. The trend was distinct in the case of constant-source diffusion. In the case of instantaneous source diffusion, both the tension and second compression fields appeared to be extremely small.

Chemical Stresses Induced by Grain-Boundary Diffusion W.L.Wang, Y.T.Chou, S.Lee: Metallurgical and Materials Transactions A, 1998, 29[8], 2121-30