Development of a grain boundary pinning model that considers particle size distribution using the phase field method

In this work, we expand a grain boundary (GB) pinning model that considers a range of different spatial distributions of particles to also account for a distribution of particle sizes. We begin by developing a phase field model that describes GB and pore interactions and verify it by comparing to molecular dynamics simulations. We then develop an analytical pinning model that considers the impact of the particle size distribution, in terms of the mean and standard deviation of the particle radius. The analytical model is verified by comparing to simulation results of our phase field model and those of a simple Monte Carlo model. A significant finding from the model is that the mean value of the resistive pressure decreases with increasing standard deviation of the particle radius.