Phase-field modeling of solid-state sintering with interfacial anisotropy

Abstract

Sintered structures observed in experiments can consist of faceted crystal grains. To predict the formation of such structures, a new phase-field (PF) model of solid-state sintering that can analyze morphological changes and microstructural evolutions considering the strong interface anisotropies of sintered particles was developed in this study. The developed PF model treats the crystal grain orientation-dependent surface and misorientation-dependent grain boundary anisotropies. Furthermore, this model employs quaternions to calculate the particle rotation, eliminating complicated calculations involved in analyzing the crystal orientation in three-dimensional (3D) simulations. The morphological change in a sintered particle and the grain boundary formulation at triple junctions simulated using the developed model were validated by comparing them with theoretical solutions. The neck growth and densification rates were investigated by performing 3D simulations using two particles with interface anisotropies. The simulation results revealed that neck growth and densification are affected by surface energy and mobility anisotropies. A 3D PF simulation using 200 particles demonstrated that the developed PF model can potentially reproduce sintered structures with faceted particles observed in experiments. The PF model provides a promising simulation for predicting the microstructural evolution of actual materials during solid-state sintering.