Surface tension-pressure superposition principle for anisotropic shrinkage of an ellipsoidal pore in viscous sintering

The shrinkage of a spherical pore is a classical model of the final stage of sintering; however, closed pores observed in real sintering have irregular shapes, which can be approximated as ellipsoids in many cases. In this study, we used the finite element simulation to evaluate the anisotropic shrinkage of a non-spherical pore. The shape evolution was expressed as the superposition of the deformation of a pore driven by surface tension and the deformation of a void driven by remote pressure in the absence of surface tension. By using this superposition principle, we can predict the shape evolution of any spheroidal pore, which is affected by the initial aspect ratio, the remote pressure, and the gas pressure inside the pore. We analyzed the role of sintering stress tensor on the anisotropic shrinkage also.