Low-Temperature Aging of Y-TZP Ceramics

The isothermal tetragonal‐to‐monoclinic transformation of a 3Y‐TZP ceramic is investigated from 70° to 130°C in water and in steam by X‐ray diffraction and optical interferometer techniques. Aging kinetics followed by X‐ray diffraction are fitted by the Mehl‐Avrami‐Johnson law, suggesting nucleation and growth to be the key mechanisms for transformation. Optical interferometer observations of highly polished samples effectively reveal a nucleation and growth micromechanism for tetragonal‐to‐monoclinic transformation. A model based on surface change analysis is developed that fits closely to the X‐ray diffraction results.