The effect of microstructural inhomogeneity on grain boundary diffusion creep

Stress concentration at grain boundaries (GB), a phenomena arising from microstructural inhomogeneity, is an important factor in determining the mechanical properties of polycrystalline materials. In this study we use mesoscopic simulations to investigate characteristics of the deformation mechanism of grain-boundary diffusion creep (Coble creep) in a polycrystalline material. The stress distribution along the grain boundaries in a polycrystalline solid under externally applied stress is determined and the mechanism of how topological inhomogeneities introduce stress concentrations is investigated. Microstructures with inhomogeneities of various sizes and distributions are considered and their effect on the stress distribution and creep rate is quantified.