碳热还原法制备Al_2O_3-SiC复相陶瓷材料的研究

Synthesis of Al_2O_3-SiC composite materials by carbon thermal reduction method

以黏土为原料,无烟煤为还原剂,研究了碳热还原反应制备Al2O3-SiC复相陶瓷材料的反应过程,探讨了合成温度(分别为1 500、1 550、1 600和1 650℃)、保温时间(依次为2、3和4 h)、配碳量(C与SiO2物质的量比分别为2、3、4和5)等工艺因素以及加入催化剂对反应的影响。结果表明:当n(C):n(SiO2)=3～4,在不低于1 600℃烧成时可以合成Al2O3-SiC复相陶瓷;随着还原反应温度的升高,保温时间的延长,配碳量的适量增加,都可以有效地促进反应进行,而且,催化剂对该碳热还原反应有一定的促进作用。

Al2O3-SiC composite materials were synthesized using clay as starting materials and anthracite coal as reducer by carbon thermal reduction reaction. The synthesis process and the influence factors were investi- gated. Effects of synthesizing temperature （; 500,1 550,1 600 and 1 650 ℃, respectively） ,soaking time （2, 3 and 4 h, respectively）, carbon content （ n（C） ： n（SiO2） =2,3,4 and 5, respectively） and catalyst on the reduction reaction were studied. The results showed that over 1 600 ℃,Al2O3-SiC composite ceramic can be synthesized when n（C） ： n（SiO2） was from 3 to 4. Increasing synthesizing temperature, soaking time and suitable C content were beneficial to the reaction process. Moreover, adding suitable catalyst could accelerate the reaction.