TiCl4对合成堇青石陶瓷热膨胀系数的影响

摘要

以MgO、Al2O3及SiO2为原料,研究了四氯化钛添加量对合成堇青石陶瓷材料热膨胀系数的影响.研究表明,适量四氯化钛能够促使堇青石晶体由低温型的β-堇青石晶相向更低热膨胀系数的高温型α-堇青石(印度石)晶相转变,从而在一定程度上降低堇青石陶瓷材料的热膨胀系数,但其添加量不宜超过5.0wt.%,否则将导致尖晶石与假蓝宝石晶相的生成而致使热膨胀系数显著升高.当四氯化钛的添加量为4.0wt.%、烧结温度为1430 ℃时,可以获得室温至800 ℃平均热膨胀系数为1.16×10-6 ℃-1的堇青石陶瓷材料.%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.