Effect of WO_3 on the Performances of Cordierite Ceramics Synthesized by Using Kyanite as Raw Materials

摘要

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 zirconium containing kyanite, common kyanite and industrial Al_2O_3 as raw materials. WO_3 (the right amount of tungsten acid) was introduced as catalyst. Effects of the introduced WO_3 on the phase composition, sintering characters, microstructures and thermal expansion coefficient of the cordierite ceramics were investigated. The results show that WO_3 can eliminate the intermediate phase magnesia-alumina spinel and promote the formation of cordierite. The as-prepared cordierite ceramics synthesized by using natural zirconium containing kyanite as raw materials have high densification degree and low thermal expansion coefficient (1.53×10~(-6)/°C, RT～1000 °C).