单质Si对含TiO_2刚玉制品烧结性能和相组成的影响

Influence of Si on sintering property and phase composition of TiO_2-containing corundum materials

以电熔白刚玉、α-Al2O3、锐钛矿和单质Si为原料,固定配料中电熔白刚玉和α-Al2O3的质量分数分别为80%和20%,锐钛矿的外加量为6%,分别外加0、2%、4%和6%的单质Si,经混练、成型、干燥后在空气气氛中于1550℃保温3h烧成,检测烧后试样的显气孔率、体积密度、耐压强度、抗折强度和线变化率,并采用XRD分析烧后试样的相组成。结果表明:在刚玉材料中同时加入锐钛矿和单质Si能降低材料的显气孔率,提高材料的抗折强度和耐压强度,并有钛酸铝和莫来石生成;另外,单质Si对材料中的钛酸铝具有较好的稳定作用,但随着单质Si含量由2%增加至6%,材料中的钛酸铝含量减少,莫来石含量增加。

The corundum materials were prepared using fused corundum,α-Al2O3, anatase and silicon as the starting materials,fixing the additions of fused corundum and α-Al2O3 ,which were 80% and 20% respectively,and extra adding 6% anatase and 0,2% ,4% and 6% silicon respectively, mixing, pressing, drying and firing at 1500 ℃ for 3 hours in air. The apparent porosity, bulk density, MOR, CCS and linear change rate were determined and the phase composition of specimen was analyzed by XRD analysis. The results showed that adding TiO2 and silicon can obviously enhance the MOR and CCS and decrease the apparent porosity of corundum materials,and accompanying the forming of aluminum titanate and muilite. Moreover,silicoh has a good stabilization effect on aluminum titanate. However, with silicon content increasing from 2% to 6%, the aluminum titanate content reduces,and the mullite content increases In the material.