Synthesis of Al2O3-SiC-TiC composite powder from silica by selfpropagating high temperature of synthesis method

The preparation of Al2O3-SiC-TiC composite powders was studied by SHS process using silica (source of SiO2) powder instead of Si which is expensive. And, aluminum powder was used as reducing agent of silica and charcoal activated was used as carbon source. Effects of the molar ratio in raw material mixtures and compaction pressure and initial temperature of reactant on the products and combustion process were studied. The most important variable affecting the synthesis of Al2O3-SiC-TiC was the molar ratio of carbon. The combustion reaction generated in powder state without preheating. But the unreactants exist in the product on all molar ratio. When the preheating temperature is over 400 degrees C, the combustion reaction was able to be generated in pellet state. Without preheating, the combustion reaction was possible by TiO2 addition. The optimum condition in this system was the molar ratio of SiO2:TiO2:Al:C=2.5:0.5:4:3.