What are the uses of silicon carbide?

 Silicon carbide products have special properties such as high temperature resistance, wear resistance, thermal shock resistance, chemical corrosion resistance, radiation resistance and excellent electrical conductivity and thermal conductivity, so they are widely used in various sectors of the national economy. In my country, green silicon carbide is mainly used as abrasive. Black silicon carbide is used in the manufacture of abrasive tools, mostly used for cutting and grinding materials with low tensile strength, such as glass, ceramics, stone and refractory materials, etc. It is also used for grinding cast iron parts and non-ferrous metal materials. Grinding tools made of green silicon carbide are mostly used for grinding hard alloys, titanium alloys and optical glass, as well as for honing cylinder liners and fine grinding of high-speed steel tools. Cubic silicon carbide abrasives are specially designed for superfinishing of miniature bearings. Coating silicon carbide micropowder on the impeller of the turbine by electroplating can greatly improve the wear resistance of the impeller; press the cubic SiC200 grinding powder and W28 micropowder into the cylinder wall of the internal combustion engine with mechanical pressure, which can prolong the life of the cylinder by a factor of 1. times more.

In the electrical industry, silicon carbide can be used as arrester valve body, silicon carbon electric heating element, far infrared generator, etc. In the electronics industry, for example, large intact silicon carbide single crystals are grown in industrial silicon carbide furnaces or in industrial furnaces by special methods, which can be used as substrates for light-emitting diodes (such as crystal lamps and digital tube lamps); high-purity silicon carbide Crystals are high-quality materials for the manufacture of radiation-resistant high-temperature semiconductors. Silicon carbide is one of the few semiconductor materials with a large band gap (2.86 eV) and two conductivity types, p and n.

In the aerospace industry, gas filters and combustion chamber nozzles made of silicon carbide have been used in rocket technology. The silicon carbide fiber that has been industrially produced is a new type of high-strength, high-modulus material with excellent heat resistance and oxidation resistance, and has excellent compatibility with metals and resins. The operating temperature can reach 1200 ℃, and the strength retention rate at high temperature can reach more than 80%. It can be used to manufacture heat shielding material, high temperature resistant conveyor belt, filter cloth for filtering high temperature gas or molten metal, and can also be used as a reinforcing material for reinforcing metals and ceramics in combination with carbon fiber or glass fiber.

Low-grade silicon carbide can be used as steel-making deoxidizer and cast iron additive.

In the carbon industry, silicon carbide is mainly used to produce bricks for iron-making blast furnaces, such as graphite silicon carbide and silicon carbide bricks combined with silicon nitride.

In the production of graphite electrodes, silicon carbide is also used in the preparation of coated refractory sintered materials for oxidation-resistant coated electrodes to increase the coating's ability to withstand rapid changes in temperature.

In the manufacture of special carbon materials - biochar, propane and trichloromethylsilane are often used as gas materials. After high temperature pyrolysis, a silicon-containing pyrolytic carbon coating is formed on the graphite substrate to increase the hardness of the product. , strength and wear resistance. The silicon carbide in the coating exists in the crystal form of β-SiC, and the grain size is about 1 μm. Biochar products manufactured by this method, such as silicon-containing pyrolytic carbon artificial heart valves, have good biocompatibility.