中文摘要：

以高岭石和无机碳为原料合成SiCw/A12O3复相陶瓷粉末,借助X射线衍射（XRD）、扫描电镜（SEM）等手段对该陶瓷粉体进行测试表征,研究合成温度和保温时间对合成产物的影响,并初步探明高岭石碳热还原反应过程和机理。结果表明：高岭石与碳在高温下反应过程由2段组成,第1段是高岭石的低温分解,第2段是高岭石分解产物SiO2和莫来石的碳化还原。其中第2段反应又由SiO2的碳化还原和莫来石的碳化还原组成,二者是先后发生而不是并列发生。在高岭石碳热还原过程中,气-固（V-S）反应机制和固-固（S-S）反应机制均有可能发生,SiC晶须的形成由占主导地位的反应机制决定。

英文摘要：

SiCw/Al2O3 ceramic composites were prepared by in-situ carbothermal synthesis using kaolinite and nano carbon black as raw materials.Effects of synthesis temperature and holding time on the products and the reaction mechanism were studied in the present paper.The synthesis products were characterized by X-ray diffraction（XRD） and scanning electron microscopy（SEM）.The in-situ carbothermal reaction of kaolinite/C at high temperature is composed of two steps.The first step is kaolinite decomposition.The second step is carbothermal reactions between SiO2 and mullite.The carbothermal reactions between SiO2 and mullite also take place step by step,the SiO2 reduces firstly at lower temperature to form SiC,then mullite reduces to form SiC/Al2O3.In the reaction of kaolinite/C,solid-solid reaction mechanism and solid-gas reaction mechanism exist together.