Synthesis of Nanocrystalline Silicon Carbide Powder by Precipitaion-spray Drying

Nanocrystalline SiC powder was synthesized by carbothermal reduction of the precur- sor of carbon black and silica gel prepared by precipitation-spray drying slurry of carbon black and water glass.The carbothermal reduction of the precursors can be completed at 1500℃for 5h be- cause the method provides intimate contact between the reactants.The product was characterized by XRD,BET,SEM and TEM,the influence of temperature and time on the reaction was also studied.The results show that the powder synthesized at 1500℃for 5h has characteristics of high quality with an average crystalline size of 37nm and specific surface area of 12.4m~2/g.It reveales that during carbonthermal reation,appropreately rising temperature and shortening reaction time will be favorable to obtain the reation product of SiC with high quality.