XIAO Zhuohao, LI Jun, Zhou Jianer, WANG Yongqing, JIE Xiaoxi, YUAN Tianhang
(School of Materials Science and Engneering, Jingdezhen Ceramic Institute, Jingdezhen 333403, Jiangxi, China)
Abstract: Serials of cordierite ceramics were synthesized by solid phase sintering method using MgO, Al2O3 and SiO2 as raw materials and TiCl4 as an additive. The effects of TiCl4 added on the thermal expansion coefficient of cordierite ceramics were investigated. The results show that an appropriate amount of TiCl4 (1.0-5.0wt %) can promote the phase transition from β-cordierite to α-cordierite (indialite) with a lower coefficient of thermal expansion. However, excessive TiCl4(>5.0 wt.%) will lead to the generation of crystals of spinel and sapphire phase, which results in the significant increasing of the thermal expansion coefficient. When the added amount of TiCl4 is 4.0 wt.% and the sintering temperature is 1430 ℃, the cordierite ceramic material with the thermal expansion coefficient of 1.16× 10-6 ℃-1 (25-800 ℃) can be obtained.
Key words: cordierite; indialite; TiCl4; coefficient of thermal expansion