Thermodynamic of solid-state sintering: Contributions of grain boundary energy

This study aimed to highlight the importance of solid -solid interfaces or grain boundaries in the thermodynamics of interfaces during the sintering of materials. Among the three chemical potentials identified in this study, the difference in chemical potential between the grain boundary and the surface emerges as the most critical factor for pore elimination. However, once equilibrium is achieved between the grain boundary and the surface, a second chemical potential associated with the difference in grain size becomes predominant, promoting a new microstructural configuration that reactivates grain boundary formation and perpetuates sintering. A third potential was identified because of the edges, contributing to the rounding of the neck region between grains. The change in interfacial energy resulting from the adsorption or segregation processes plays a pivotal role in pore elimination during sintering. Models attempting to simultaneously predict the stability of grain boundary formation and pore elimination with grain growth were revisited.