Microstructural Evolution in a ZrO ₂ Wt% Y ₂ O ₃ Ceramic

Abstract

Several unusual microstructural features, i.e., 90° tetragonal ZrO 2 twins containing antiphase domain boundaries, tetragonal ZrO 2 precipitates in a colony morphology, and precipitate‐free zones at the perimeter of cubic ZrO 2 grains containing fine tetragonal ZrO 2 precipitates, were observed in a single ZrO 2 ‐12 wt% Y 2 O 2 ceramic annealed at 1550°, 1400°, and 1250°C, respectively. The type of phase transformation responsible for each microstructural feature is described.