Methods to calculate sintering stress of porous materials in equilibrium Original Research Article

The sintering stress is originally defined for equilibrium states, where the mechanical stress just balances the internal surface tension forces so that the porous material does not shrink. The sintering stress for a given porous structure in equilibrium was calculated by three methods theoretically; the energy difference method, the curvature method, and the force balance method. The sintering stresses by three different methods were exactly the same for idealized porous materials in equilibrium, in which the pore surface had a constant curvature at any point. The grain boundary energy contributed to the sintering stress, and it affected the thermal stability of the porous structure.