Preparation of silicon carbide by microwave sintering

Silicon carbide was prepared by microwave sintering method with silicon powder and acetylene carbon black as raw materials. The effects of compactness and particle size of the reactants on the product particle size and morphology were discussed. The morphology of silicon carbide was observed by SEM and TEM. The results show that when the acetylene carbon black and silicon powder with free packing are made as the reactants, SiO and CO can be obtained from the reaction between the reactants and oxygen on the surface of reactants, and then both silicon carbide whisker and particulates can grow by the gas-gas reaction; when the reactants are pressurized, the silicon carbide particles are obtained from the reaction between SiO and the mixture of Si and C. Silicon carbide is generated by the diffusion mechanism in the process of the reaction of acetylene carbon black and silicon powder, and the size of silicon carbide particle is determined by the carbon particle size. ©, 2015, Editorial Office of Transactions of Materials and Heat Treatment. All right reserved.