Characteristics and Uses of Silicon Carbide Products

To produce silicon carbide products, the first thing you need is silicon carbide raw materials. Silicon carbide industrial production method is the quartz sand (56%), coal coke (35%), sawdust (7%) and salt (2%) mixed together in a resistance furnace heated to about 2200 ° C. The role of salt is to remove impurities in the quartz sand and coal coke, and the role of the sawdust is to produce air holes, so that the generated gas can easily escape. The middle of the electric furnace is stacked with graphite or carbon particles to form a columnar resistance heat generator, and the allocated raw materials are closely filled around the heat generator. Sintered lump crystals by crushing, acid, alkali, washing, and then magnetic separation to remove traces of iron, drying that is the raw material of silicon carbide.

Silicon carbide products can be manufactured by reaction sintering method. The particle size of the appropriate proportion of a-Sic powder and colloidal graphite in the porcelain ball mill barrel evenly mixed 20h, add the binding agent carboxymethyl cellulose or polyvinyl alcohol alcohol solution, molded in a steel mold, the pressure is 50 ~ 70MPa. Silicon carbide melting point, low specific gravity, Mohs hardness of 9.2, high strength, thermal shock stability is better, insoluble in water and acid, but can be dissolved in the molten alkali. Silicon carbide in 800 ~ 1140 ℃ between the poor antioxidant capacity, because at this time the generation of the oxide film (SiO2) is more loose, not play a sufficient protective effect. When the temperature rises to 1550 ℃, its antioxidant performance becomes better.

Silicon carbide can be used in the manufacture of abrasives, abrasives: used in the manufacture of silicon-carbon rods, silicon-carbon tubes and other electrical resistance heating elements: used in the manufacture of jet aircraft, gas turbines, rocket engines, tail nozzle, etc., used in the manufacture of molten metal pipeline, filters, crucibles, etc.: more importantly, it is used in the manufacture of special refractory products, used in the erosion, wear and tear of serious parts.