Smoothed Boundary Method for simulating bulk and grain boundary transport in complex polycrystalline microstructures

Abstract

Grain boundaries have a major impact on material properties, but explicit consideration of the complex geometries of grain structures in simulations poses a challenge. In this paper, we present a general method for incorporating the effect of grain boundaries based on the Smoothed Boundary Method (SBM). By using multiple domain parameters to define the domains of different grains, this method circumvents time-consuming mesh generation steps that are associated with finite element calculations involving complex microstructures. To validate the approach, we evaluate the accuracy of the SBM against the sharp interface method. The capabilities of this approach were demonstrated through simulations of surface and grain boundary diffusion, as well as those of electrochemical impedance spectroscopy. This method is applicable to many material systems in which grain boundaries play a crucial role.