Shrinkage Behaviors and Sintering Mechanism of BaTiO3 Ceramics in Two-Step Sintering

The shrinkage behaviors of BaTiO 3 ceramics in a nonisothermal process were quantitatively monitored to clarify the mechanism of two-step sintering. During the increase in temperature, shrinkage behaviors due to grain boundary diffusion, volume diffusion, and grain rearrangement were observed. From the analysis of the shrinkage curve and the observation of the microstructure, the first step in two-step sintering was interpreted as a process for eliminating large pores by grain rearrangement. In contrast, the second step was interpreted as a process for final densification by volume diffusion. It was clarified that the analysis of shrinkage behaviors was useful for understanding two-step sintering and for determining suitable sintering conditions.