Phase-field simulation of the interaction between intergranular voids and grain boundaries during radiation in UO₂

In the present work, a phase-field model is developed to simulate the interaction between voids and grain boundary (GB) by a set of modified Cahn-Hilliard and Allen-Cahn equations with spatially and temporally evolving field variables and order parameters. Both the evolution of grain growth and the effect of moving GBs on the formation of voids during radiation were captured in the present phase-field model. A flat GB with an artificial driving force was used to analyze the resistive pressure of the void during the interaction of the void and moving GB, and the interaction between GB and void with different radius was also simulated. The effects of moving GB on the void formation during radiation was also discussed in detail. In addition, the grain growth and voids formation during radiation in polycrystalline uranium dioxide were studied based on the modified phase-field model.