A Study on Crystallization of Fused Silica/Zirconia Ceramic Composites

Fused silica particles and zirconyl chloride were used as main raw material. Meanwhile, ammonia was used as precipitator and polyethylene glycol as dispersant. Firstly, the composite powders were prepared by wet chemical synthesis. Then, fused silica/zirconia ceramic composites containing zirconia with different contents (5%, 15%, 25%, 35% and 45%) were fabricated in reduction atmosphere at 1300°C, 1350°C and 1400°C for 1 h. The thermal expansion ratios and XRD of samples were examined. The analysis of XRD indicated that the cristobalite peaks intensity of sample with more zirconia is lower at the same sintering temperature, and the intensity of cristobalite was higher while sintered at higher temperature. Zircons were found in all samples’ XRD patterns. The results of thermal expansion ratios showed the ratios of samples with more zirconia were lower, especially at higher sintering temperature. So, existence of zirconia can inhibit crystallization of fused silica/zirconia ceramic composites effectively.