Numerical simulation of microstructural evolution during sintering at the mesoscale in a 3D powder compact

This paper presents a numerical model that is capable of simulating microstructural evolution during simple solid-state sintering of a complex 3D powder particle compact. This model, a Potts kinetic Monte Carlo model, is a true mesoscale model that can simulate a large number of particles while resolving microstructural features such as particles, necks, pores and more in detail. Furthermore, it is shown that this model can simulate all the stages of sintering from the initial particle contact to neck growth with open, percolating porosity to closed isolated pores seamlessly. The various kinetic processes that lead to densification and other microstructural changes are shown to be simulated correctly. The model is demonstrated by comparing the microstructural evolution resulting from simulation to experimental results, namely 3D microtomographic images obtained from synchrotron radiation of a Cu-powder compact while it was sintering. For quantitative comparison, we extrapolated a grain structure into the simple microtomographic image that consists of mass distribution only.