Silicon Carbide Ceramics Main Applications

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In recent years, the research and application of high performance silicon carbide ceramics have attracted much attention. As one of the modern engineering ceramics, silicon carbide ceramics have outstanding physicochemical properties, such as low thermal expansion coefficient, high thermal conductivity, good chemical stability, high wear resistance, good mechanical properties and oxidation resistance at high temperature. At the same time, SiC also has low neutron activity, good radiation damage resistance and high temperature structural stability. It has become a structural ceramics with great development prospects. Therefore, it is widely used in petrochemical industry, metallurgical machinery, microelectronic devices and aerospace and other fields.

The initial application of SiC is due to its superhard properties, which can be prepared into grinding wheels, abrasive cloth, abrasive paper and various abrasives for grinding, so it is widely used in the mechanical processing industry. In World War II, it was found that it could also be used as reducing agent and heating element in steelmaking, thus promoting the rapid development of SiC. SiC ceramics have been widely used in petroleum, chemical industry, microelectronics, automotive, aerospace, aviation, paper-making, laser, mining and atomic energy industries. Silicon carbide has been widely used in high-temperature bearings, bullet-proof plates, nozzles, high-temperature corrosion-resistant components and high-temperature and high-frequency range of electronic equipment components and other fields.

SiC ceramics not only have excellent mechanical properties at room temperature, such as high flexural strength, excellent oxidation resistance, good corrosion resistance, high wear resistance and low friction coefficient, but also have the best mechanical properties (strength, creep resistance, etc.) at high temperature. The high temperature strength of materials sintered by hot pressing, pressureless sintering and hot isostatic pressing can be maintained up to 1600 C, which is the best high temperature strength material in ceramic materials. Antioxidant activity is also the best of all non-oxide ceramics. Alias diamond.

1. Abrasives – mainly because silicon carbide has high hardness, chemical stability and certain toughness, so silicon carbide can be used to manufacture consolidated abrasives, coated abrasives and free grinding, so as to process glass, ceramics, stone, cast iron and some non-ferrous metals, cemented carbides, titanium alloys, high-speed steel tools and grinding wheels.

2. Refractories and corrosion-resistant materials – mainly because silicon carbide has high melting point (decomposition), chemical inertia and thermal vibration resistance, so silicon carbide can be used for grinding tools, shed boards and saggers used in ceramic products firing kilns, silicon carbide bricks used in vertical cylinder distillation furnaces of zinc smelting industry, lining of aluminium electrolytic cells, crucibles, small pieces of furnace materials and other silicon carbide ceramics.

3. Chemical applications – because silicon carbide can be decomposed in molten steel and react with oxygen and metal oxides in molten steel to produce carbon monoxide and silicon-containing slag. Therefore, it can be used as a purifier for steelmaking, i. e. as a deoxidizer for steelmaking and a structure modifier for cast iron. This generally uses low purity silicon carbide to reduce costs. It can also be used as raw material for the manufacture of silicon tetrachloride.

4. Electrical Applications – Used as Heating Elements, Nonlinear Resistance Elements and High Semiconductor Materials. Heating elements such as silicon-carbon rods (suitable for all kinds of electric furnaces operating at 1100-1500 C), non-linear resistance elements, and various lightning arresters.

5. Other far-infrared radiation coatings or far-infrared radiation dryers for silicon carbide boards.