Effects of processing parameters and rare earths additions on preparation of Al2O3-SiC composite powders from coal ash

Al2O3-SiC composite powders were successfully fabricated from coal ash by carbothermal reduction reaction (CRR) method in argon atmosphere. The effects of raw materials ratio, reaction temperature, La2O3 and Sm2O3 additions on the synthesis process were investigated in detail. Phase compositions and microstructures of Al2O3-SiC composite powders were characterized by XRD and SEM. Proper processing parameters and rare earths addition amounts were determined, and the formation process of Al2O3-SiC powders was also discussed.