Finite-element meso-scale models provided a means of investigating the driving forces for particle evolution during sintering, and comparing the differing behaviours of the sintering of glassy particles by viscous flow and the sintering of idealized crystalline systems, without a grain boundary, via vacancy diffusion. The effects of a grain boundary were here included in the meso-scale model, and the resultant behaviour was compared with previous cases. A grain boundary acted as a sink for vacancies: drawing a flux towards itself and allowing their accumulation and collapse. The resultant solid-body motion of the particles led to significant shrinkage at the onset of sintering. Neck growth, with little shrinkage, was observed in systems without a grain boundary. These effects were influenced by the magnitude of the grain-boundary diffusivity and the size of the dihedral angle.

Transport Mechanisms and Densification During Sintering II - Grain Boundaries. H.Djohari, J.J.Derby: Chemical Engineering Science, 2009, 64[17], 3810-6