Abstract

Zirconia is an inorganic, nonmetallic material with excellent properties. However, the brittleness of the zirconia, resulting from the thermal performance during the heating and cooling process, seriously limits the application of zirconia in the metallurgical, military, and aerospace industries. Al₂O₃ doped ZrO₂ was developed to improve the potential material’s toughness. This paper studied the evolution of the surface functional groups, phase composition, toughening mechanism, and particle morphology of Al₂O₃ doped ZrO₂ during the heating process. Especially microwave heating was selected as the heating method during the experiments to save energy consumption. The results showed that the phase transition temperature was reduced by the microwave sintering technique, which also promoted the transformation between the m-ZrO₂ and t-ZrO₂, advancing the crystallinity and structural properties of the samples. The specific surface area shows a positive relationship with the microwave heating temperature, while the particle size of the powder decreased with the temperature increase. The optimized sintering effect appears at 1000 °C in the studied roasting temperature range (800 °C–1200 °C) for Al₂O₃–ZrO₂ powders. With the optimized sintering temperature, the void of the granular zirconia material was controlled, and the best micromorphology was obtained. In practical production, the application of microwave sintering and alumina doping is beneficial to saving costs and protecting the environment.