Diffusive creep in polycrystals

We report quantitative mesoscopic calculations of diffusive creep in polycrystals under external stress. The analysis includes mass transport both in the grains and along the grain boundaries, full coupled with elastic deformations in the grains and the evolution of the displacement field. We find that the net creep rate depends strongly on the details of grain boundary arrangements. The calculations represent a first step toward a comprehensive first-principles theory of plasticity.