Insight into void formation near grain boundary from phase-field simulations

Abstract Numerous point defects (vacancies and self-interstitials) generated during irradiation can diffuse and accumulate to form defect clusters inside grains or at grain boundaries (GBs). Void-denuded zone (VDZ) near the GB is related to irradiation condition, GB character and the kinetics of defects at the GB region. A phase-field model is developed to simulate void formation near different types of GBs. The sink term representing the annihilation of GB is modified by taking into account of the inclination angle for Σ GB and the defect mobility. The temperature-dependent material parameters of copper are derived from ab initio calculations. According to the numerical simulations, the boundaries of VDZs tend to move towards the interior grains with increasing the efficiency of GB sink term. In the neighboring region of the denuded zone, the number of voids increases rapidly and the average radius of void is higher than that far from the VDZs.