Preparation of Dense ZrO2/ZrW2O8 Cosintered Ceramics with Controlled Thermal Expansion Coefficients

Various kinds of ZrO2-ZrW2O8 composite ceramics were successfully prepared by cosintering of ZrO2 and ZrW2O8 mixture with various ratios at 1200°C. The thermal expansion coefficient of the composite could be controlled from -9.6×10-6 K-1-8.2×10-6 K-1 by varying ZrO2/ZrW2O8 ratios and zero thermal expansion was observed in the specimen with a ZrO2/ZrW2O8 weight ratio of 2/1. A small amount of Al2O3 addition less than 0.25 mass% was effective in increasing the density of the composite. It was suggested that the generation of a liquid phase of Al2(WO4)3 improved the sintering property of the ZrO2-ZrW2O8 mixture.