Effect of sintering time on the microstructure and stability of Al2O3–ZrO2 composite powders under microwave-assisted sintering

The function of ceramic coating is closely related to the construction technology and the quality of ceramic powders. Generally, Al2O3–ZrO2 powders are rapidly sprayed on the material surface at high temperatures to obtain better performance. Improving the quality of Al2O3–ZrO2 powders can make them more widely used in ceramic coating. In this paper, microwave sintering was used to enhance the sintering process of the powders, and the effect of sintering time on the microstructure, properties, and stability of Al2O3–ZrO2 powders was investigated. The results proved that microwave heating could improve the crystallinity and stability of the samples. At 900 °C, the tetragonal phase content in samples with different sintering times were 63.05%, 63.25%, 62.39%, and 63.22%, respectively. The average particle sizes obtained by Gaussian fitting are 1.04 μm, 0.83 μm, 0.88 μm, 0.86 μm, respectively. The Gaussian fitting particle size data was consistent with the normal distribution. Compared with the particle size of raw material (1.10 μm), the particles were refined, and the dispersion effect was noticeable. Therefore, the best sintering time for microwave sintering Al2O3 stabilized zirconia was 2 h. This paper aims to provide reasonable data support for improving the preparation of high-quality Al2O3-PSZ ceramic powders and to guide the industrial production of Al2O3-PSZ powders.