Effect of WO3 on the Performances of Cordierite Ceramics Synthesized by Using Kyanite as Raw Materials

In order to synthesize cordierite ceramics with low thermal expansion coefficient and good properties, in our work, the cordierite ceramics were prepared by using talc, natural containing zirconium kyanite, common kyanite and industrial Al2O3 as raw materials, introducing the right amount of WO3 (introducing tungsten acid) as catalyst. The effects of the introduced WO3 on the phase composition, sintering characters, microstructure and thermal expansion coefficient of the cordierite ceramics were investigated. The results show that the introduction of WO3 can eliminate the intermediate phase magnesia-alumina spinel and promote the formation of cordierite; the as-prepared cordierite ceramics synthesized by using natural containing zirconium kyanite as raw materials have high densification degree and low thermal expansion coefficient (1.53×10-6/°C, Rt~1000 °C).