Computational Mesoscale Modeling and Homogenization of Liquid-Phase Sintering of Particle Agglomerates

Abstract

Liquid phase sintering of particle agglomerates is simulated as the viscous deformation due to particle-particle contact, whereby the single driving force is the surface tension on the particle/pore interface. Particles are modeled as purely viscous fluids (with no elasticity). Computational homogenization is adopted for the RVE with Dirichlet boundary conditions. A surface motion algorithm was developed that requires complete remeshing of the FE-mesh based on a maximum deformation criterion. Since the particles are intrinsically incompressible, the macroscopic compressibility is determined from shrinking porosity in the substructure. The numerical examples include free sintering of an RVE and a fully coupled FE²-simulation of a specimen with inhomogeneous initial distribution of porosity.