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Characteristics, uses and preparation processes of nitrogen-carbon bonded silicon carbide products
- Aug 22, 2018 -

Both silicon nitride and silicon carbide in nitrogen-carbon bonded silicon carbide products are highly covalently bonded compounds with similar physical and chemical properties and maintain high bonding strength at high temperatures. The silicon powder uniformly surrounds the silicon carbide and undergoes high-temperature nitridation reaction to form a dense network structure. Therefore, the silicon nitride-bonded silicon carbide product has a series of excellent properties such as high temperature resistance, corrosion resistance, wear resistance, erosion resistance and oxidation resistance.


Moreover, the nitrogen-carbon-bonded silicon carbide product also has good resistance to all inorganic acids other than hydrofluoric acid, is not wetted by molten metal, especially non-ferrous metal liquid, and can withstand the erosion of most non-ferrous metal melts. As a high-grade refractory material, the normal use temperature can reach 1500 °C in various atmospheres. It is widely used in ceramics, non-ferrous metallurgy, iron and steel metallurgy, powder metallurgy, chemical industry and other industries.


The main preparation methods of silicon nitride-bonded silicon carbide products include silicon powder direct nitridation method, carbothermal reduction silica method, Si(NH)2 thermal decomposition method, SiH4 and NH3 gas phase reaction method. Generally, the method for forming silicon nitride in the reaction-sintered silicon nitride-bonded silicon carbide product is a direct nitridation method of silicon powder, and diffuses into the silicon powder particles through nitrogen at a high temperature to form silicon nitride.


In general, the preparation of nitrogen-carbon bonded silicon carbide products requires various processes such as raw material processing, compounding, compounding, molding, drying, nitriding, and product inspection, and the products are manufactured in refractory materials and other industries. More and more extensive.