| Abstract Scope |
Sintering of ceramics is a processing methodology that benefits from the contributions from individual point defects (vacancies and interstitials) line defects (dislocations), and surfaces and interfaces, as they interact in a local microstructural, mechanical, chemical, and electrical field induced through local or external stimuli. In this presentation, by starting from thermodynamic concepts, a phase field theory is presented to describe the chemical and electric field-induced mechanisms that control the forces, dynamics, and phase transformations experienced by dislocations in ionic ceramics. Well known aging phenomena observed in metals, such as the Cottrell effect and the Portevin-Le Chatelier effect, are revisited in the context of the underlying ionic character of ceramics. The impact of these mechanisms at the particle level are assessed, and its coupling to the macroscopic sintering curves are reviewed. Applications to Y2O3, 3YSZ, TiO2, and Al2O3 will be presented. |