Silicon carbide is a synthetic carbide with the molecular formula SiC. It is usually formed by silicon dioxide and carbon at a high temperature of more than 2000 ° C after electrification. The theoretical density of silicon carbide is 3.18g/cm3, its Mohs hardness is second only to diamond, between 9.2-9.8, and its microhardness is 3300kg/mm3. Because of its high hardness, high wear resistance, high corrosion resistance and relatively high hardness. High temperature strength and other characteristics, are used in a variety of wear-resistant, corrosion-resistant and high-temperature mechanical parts, is a new type of new engineering ceramic materials.
Development History
Silicon carbide is a kind of carbide accidentally discovered in the laboratory by American Acheson during the fused diamond experiment in 1891. At that time, it was mistaken for a mixture of diamonds, so it was named emery, which was researched by Acheson in 1893. The method of industrial smelting silicon carbide, which is often referred to as Acheson furnace, has been used until now. A resistance furnace with carbonaceous material as the furnace core body is electrically heated to generate silicon carbide by heating the mixture of quartz SIO2 and carbon.
Several events about silicon carbide
Silicon carbide was first discovered in a meteorite in 1905.
1907 The first silicon carbide crystal light-emitting diode was born.
In 1955, a major breakthrough in theory and technology, LELY proposed the concept of growing high-quality carbonization, and SiC has been used as an important electronic material since then.
In 1958, the first World Silicon Carbide Conference was held in Boston for academic exchanges.
1978 In the 1960s and 1970s, silicon carbide was mainly studied by the former Soviet Union. In 1978, the grain purification growth method of "LELY Improvement Technology" was adopted for the first time.
From 1987 to now, a silicon carbide production line has been established based on the research results of CREE, and suppliers have begun to provide commercial silicon carbide bases.
Scope of application
Silicon carbide has four main application areas, namely: functional ceramics, advanced refractories, abrasives and metallurgical raw materials. The crude silicon carbide material can be supplied in large quantities, and cannot be regarded as a high-tech product, and the application of nano-scale silicon carbide powder with extremely high technological content cannot form economies of scale in a short period of time.
As an abrasive, it can be used for abrasive tools, such as grinding wheel, oil stone, grinding head, sand tile, etc.
As metallurgical deoxidizer and high temperature resistant material.
(3) High-purity single crystals can be used to manufacture semiconductors and silicon carbide fibers.
Main application: used for wire cutting of 3-12 inch monocrystalline silicon, polycrystalline silicon, potassium arsenide, quartz crystal, etc. Solar photovoltaic industry, semiconductor industry, piezoelectric crystal industry engineering processing materials. For Semiconductors, Lightning Rods, Circuit Components, High Temperature Applications, UV Detectors, Materials of Construction, Astronomy, Disc Brakes, Clutches, Diesel Particulate Filters, Filament Pyrometers, Ceramic Films, Cutting Tools, Heating Elements, Nuclear Fuel , jewelry, steel, protective gear, catalyst carrier and other fields.
Abrasives
It is mainly used for grinding and polishing of grinding wheel, sandpaper, abrasive belt, oil stone, grinding block, grinding head, grinding paste and monocrystalline silicon, polycrystalline silicon and piezoelectric crystal in the electronic industry in photovoltaic products.
Chemical
It can be used as a deoxidizer for steelmaking and a modifier of cast iron structure, as a raw material for the manufacture of silicon tetrachloride, and is the main raw material for the silicone resin industry. Silicon carbide deoxidizer is a new type of strong composite deoxidizer, which replaces the traditional silicon powder to deoxidize. Steelmaking efficiency, improving steel quality, reducing raw and auxiliary material consumption, reducing environmental pollution, improving working conditions, and improving the comprehensive economic benefits of electric furnaces are all of great value.
"Three resistant" material
Using silicon carbide has the characteristics of corrosion resistance, high temperature resistance, high strength, good thermal conductivity, and impact resistance. , Silicon carbide crucible, etc.
On the other hand, it can be used for high-temperature indirect heating materials in the non-ferrous metal smelting industry, such as vertical tank distillation furnace, rectification furnace tray, aluminum electrolytic cell, copper melting furnace lining, arc plate for zinc powder furnace, thermocouple protection tube, etc. ; Used to make high-grade silicon carbide ceramic materials such as wear resistance, corrosion resistance and high temperature resistance; it can also be used to make rocket nozzles, gas turbine blades, etc. In addition, silicon carbide is also one of the ideal materials for solar water heaters for highways and aviation runways.
non-ferrous metals
The use of silicon carbide has high temperature resistance, high strength, good thermal conductivity and impact resistance, and is used as a high-temperature indirect heating material, such as solid pot distillation furnace, rectification furnace tray, aluminum electrolytic cell, copper melting furnace lining, zinc powder furnace arc Type plate, thermocouple protection tube, etc.
Steel
Using the characteristics of corrosion resistance, thermal shock resistance, wear resistance and good thermal conductivity of silicon carbide, it is used in the lining of large blast furnaces to improve the service life.
Metallurgical beneficiation
Silicon carbide is second only to diamond in hardness, and has strong wear resistance. It is an ideal material for wear-resistant pipes, impellers, pump chambers, cyclones, and hopper linings. Its wear resistance is 5% of the service life of cast iron and rubber. --20 times &def is also one of the ideal materials for aviation flight runways.
Building materials ceramic grinding wheel industry
Taking advantage of its thermal conductivity, thermal radiation, high thermal strength and high thermal strength, the manufacture of thin-plate kiln furniture can not only reduce the capacity of the kiln furniture, but also improve the loading capacity and product quality of the kiln, and shorten the production cycle. Ideal indirect material.
Energy saving
Using good thermal conductivity and thermal stability as a heat exchanger, the fuel consumption is reduced by 20%, the fuel is saved by 35%, and the productivity is increased by 20-30%, especially the internal discharge of the discharge pipeline used in the mine dressing plant, its wear resistance It is 6--7 times of ordinary wear-resistant materials.
Abrasive particle size and its composition according to GB/T2477--83. The determination method of abrasive particle size composition is according to GB/T2481--83.
Jewelry
Synthetic Moissanite, also known as synthetic moissanite, synthetic moissanite (chemical composition SiC), has a dispersion of 0.104 larger than diamond (0.044), a refractive index of 2.65-2.69 (diamond 2.42), and has the same diamond luster as diamond. The "fire" is stronger and closer to a diamond than any imitation ever made. This is manufactured by C3 Company in North Carolina, USA, and has the patent for the production of synthetic silicon carbide in various countries in the world, and is being promoted and applied all over the world. ■
Properties and applications of Silicon carbide material
Silicon carbide is a synthetic carbide with the molecular formula SiC. It is usually formed by silicon dioxide and carbon at a high temperature of more than 2000 ° C after electrification. The theoretical density of silicon carbide is 3.18g/cm3, its Mohs hardness is second only to diamond, between 9.2-9.8, and its microhardness is 3300kg/mm3. Because of its high hardness, high wear resistance, high corrosion resistance and relatively high hardness. High temperature strength and other characteristics, are used in a variety of wear-resistant, corrosion-resistant and high-temperature mechanical parts, is a new type of new engineering ceramic materials.
Development History
Silicon carbide is a kind of carbide accidentally discovered in the laboratory by American Acheson during the fused diamond experiment in 1891. At that time, it was mistaken for a mixture of diamonds, so it was named emery, which was researched by Acheson in 1893. The method of industrial smelting silicon carbide, which is often referred to as Acheson furnace, has been used until now. A resistance furnace with carbonaceous material as the furnace core body is electrically heated to generate silicon carbide by heating the mixture of quartz SIO2 and carbon.
Several events about silicon carbide
Silicon carbide was first discovered in a meteorite in 1905.
1907 The first silicon carbide crystal light-emitting diode was born.
In 1955, a major breakthrough in theory and technology, LELY proposed the concept of growing high-quality carbonization, and SiC has been used as an important electronic material since then.
In 1958, the first World Silicon Carbide Conference was held in Boston for academic exchanges.
1978 In the 1960s and 1970s, silicon carbide was mainly studied by the former Soviet Union. In 1978, the grain purification growth method of "LELY Improvement Technology" was adopted for the first time.
From 1987 to now, a silicon carbide production line has been established based on the research results of CREE, and suppliers have begun to provide commercial silicon carbide bases.
Scope of application
Silicon carbide has four main application areas, namely: functional ceramics, advanced refractories, abrasives and metallurgical raw materials. The crude silicon carbide material can be supplied in large quantities, and cannot be regarded as a high-tech product, and the application of nano-scale silicon carbide powder with extremely high technological content cannot form economies of scale in a short period of time.
As an abrasive, it can be used for abrasive tools, such as grinding wheel, oil stone, grinding head, sand tile, etc.
As metallurgical deoxidizer and high temperature resistant material.
(3) High-purity single crystals can be used to manufacture semiconductors and silicon carbide fibers.
Main application: used for wire cutting of 3-12 inch monocrystalline silicon, polycrystalline silicon, potassium arsenide, quartz crystal, etc. Solar photovoltaic industry, semiconductor industry, piezoelectric crystal industry engineering processing materials. For Semiconductors, Lightning Rods, Circuit Components, High Temperature Applications, UV Detectors, Materials of Construction, Astronomy, Disc Brakes, Clutches, Diesel Particulate Filters, Filament Pyrometers, Ceramic Films, Cutting Tools, Heating Elements, Nuclear Fuel , jewelry, steel, protective gear, catalyst carrier and other fields.
Abrasives
It is mainly used for grinding and polishing of grinding wheel, sandpaper, abrasive belt, oil stone, grinding block, grinding head, grinding paste and monocrystalline silicon, polycrystalline silicon and piezoelectric crystal in the electronic industry in photovoltaic products.
Chemical
It can be used as a deoxidizer for steelmaking and a modifier of cast iron structure, as a raw material for the manufacture of silicon tetrachloride, and is the main raw material for the silicone resin industry. Silicon carbide deoxidizer is a new type of strong composite deoxidizer, which replaces the traditional silicon powder to deoxidize. Steelmaking efficiency, improving steel quality, reducing raw and auxiliary material consumption, reducing environmental pollution, improving working conditions, and improving the comprehensive economic benefits of electric furnaces are all of great value.
"Three resistant" material
Using silicon carbide has the characteristics of corrosion resistance, high temperature resistance, high strength, good thermal conductivity, and impact resistance. , Silicon carbide crucible, etc.
On the other hand, it can be used for high-temperature indirect heating materials in the non-ferrous metal smelting industry, such as vertical tank distillation furnace, rectification furnace tray, aluminum electrolytic cell, copper melting furnace lining, arc plate for zinc powder furnace, thermocouple protection tube, etc. ; Used to make high-grade silicon carbide ceramic materials such as wear resistance, corrosion resistance and high temperature resistance; it can also be used to make rocket nozzles, gas turbine blades, etc. In addition, silicon carbide is also one of the ideal materials for solar water heaters for highways and aviation runways.
non-ferrous metals
The use of silicon carbide has high temperature resistance, high strength, good thermal conductivity and impact resistance, and is used as a high-temperature indirect heating material, such as solid pot distillation furnace, rectification furnace tray, aluminum electrolytic cell, copper melting furnace lining, zinc powder furnace arc Type plate, thermocouple protection tube, etc.
Steel
Using the characteristics of corrosion resistance, thermal shock resistance, wear resistance and good thermal conductivity of silicon carbide, it is used in the lining of large blast furnaces to improve the service life.
Metallurgical beneficiation
Silicon carbide is second only to diamond in hardness, and has strong wear resistance. It is an ideal material for wear-resistant pipes, impellers, pump chambers, cyclones, and hopper linings. Its wear resistance is 5% of the service life of cast iron and rubber. --20 times &def is also one of the ideal materials for aviation flight runways.
Building materials ceramic grinding wheel industry
Taking advantage of its thermal conductivity, thermal radiation, high thermal strength and high thermal strength, the manufacture of thin-plate kiln furniture can not only reduce the capacity of the kiln furniture, but also improve the loading capacity and product quality of the kiln, and shorten the production cycle. Ideal indirect material.
Energy saving
Using good thermal conductivity and thermal stability as a heat exchanger, the fuel consumption is reduced by 20%, the fuel is saved by 35%, and the productivity is increased by 20-30%, especially the internal discharge of the discharge pipeline used in the mine dressing plant, its wear resistance It is 6--7 times of ordinary wear-resistant materials.
Abrasive particle size and its composition according to GB/T2477--83. The determination method of abrasive particle size composition is according to GB/T2481--83.
Jewelry
Synthetic Moissanite, also known as synthetic moissanite, synthetic moissanite (chemical composition SiC), has a dispersion of 0.104 larger than diamond (0.044), a refractive index of 2.65-2.69 (diamond 2.42), and has the same diamond luster as diamond. The "fire" is stronger and closer to a diamond than any imitation ever made. This is manufactured by C3 Company in North Carolina, USA, and has the patent for the production of synthetic silicon carbide in various countries in the world, and is being promoted and applied all over the world. ■