Viscous Sintering on a Rigid Substrate

Two analyses are presented for the sintering kinetics of a porous glass layer on a rigid substrate. The first treatment uses a continuum model, with constitutive equations and the free strain rate derived from an appropriate microstructural model. Predictions are obtained for the sintering kinetics and the magnitude of the tensile stress in the layer. During sintering, shrinkage is not permitted in the plane of the substrate, but the resulting microstructural anisotropy is ignored by the model. A second treatment represents the sintering layer by tubes whose axes are normal to the substrate. The densification kinetics of this model are in reasonable agreement with the results of the continuum model. Therefore, the effects of microstructural anisotropy (pore orientation) are likely to be small, and either model can be used