ABSTRACT
This chapter discusses a theoretical analysis of densification in solid-state and viscous sintering. In contrast to solid-state sintering, the analysis of viscous sintering appears relatively simple in principle. The sintering phenomena in polycrystalline materials are considerably more complex than those in viscous sintering of amorphous materials because of the availability of several matter transport paths and the presence of grain boundaries. Several theoretical approaches have been used to analyze the densification process during sintering, including the use of analytical models, scaling laws, and numerical simulations. These approaches, particularly the analytical models, have been criticized because the drastic simplifications assumed in the models make them unsuitable for quantitatively predicting the sintering behavior of real powder systems. The chapter outlines a more general approach based on the flux of atoms driven by a chemical potential gradient.
