In the gem world, silicon carbide is also called “Mosang Stone”. The market sees synthetic Mosang stone. The natural Moissanite is extremely rare, rare to appear only in the crater 50,000 years ago.
According to the gem world: Mozambique's fire is 2.5 times that of diamonds; the dispersion value is 0.104 (diamond is 0.044); the refractive index is 2.654 and the diamond is 2.417; the diamond Mohs hardness is 10, and the hardness is the king. Mosang stone also has 9.2-9.8, which is much higher than other gems. Therefore, the Mosang stone processed under the same conditions is not inferior to the diamond stone, and it is also known as the “Mosang Diamond”.
In the traditional industrial field, silicon carbide is mainly used as a refractory material, abrasives and metallurgical materials, which will be separately analyzed below.
1. Advanced refractory material: It utilizes the characteristics of corrosion resistance, high temperature resistance, high strength, good thermal conductivity and impact resistance of silicon carbide materials. It can be used on various aspects of smelting furnace lining, high temperature furnace kiln components, silicon carbide sheets, lining boards, Supports, shackles, 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, arc-shaped plate for zinc powder furnace, thermocouple protection tube, etc.; for making advanced silicon carbide such as wear resistance, corrosion resistance and high temperature resistance. Ceramic materials; can also be made into rocket nozzles, gas turbine blades and so on. In addition, silicon carbide is also an ideal material for highways, aviation runway solar water heaters and so on. Therefore, silicon carbide also has a common name called "refractory sand", although it is very vulgar but fully explains its fire resistance.
2, abrasives: mainly because silicon carbide has a very high hardness, Mohs hardness of 9.2-9.8, second only to the world's hardest diamond (10), so commonly known as "golden steel sand", also has a good Chemical stability and certain toughness, it can be used for the grinding of grinding wheels, sandpaper, abrasive belts, oilstones, grinding blocks, grinding heads, abrasive pastes and piezoelectric crystals in monocrystalline silicon, polycrystalline silicon and electronic industries. Polishing, etc.
3. Metallurgical raw materials: Silicon carbide can be used as a deoxidizer for steel making and a modifier for cast iron structure. It can be used 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 carbon powder for deoxidation. Compared with the original process, the physical and chemical properties are more stable, the deoxidation effect is better, the deoxidation time is shortened, energy is saved, and the energy is improved. Steelmaking efficiency, improving the quality of steel, reducing the consumption of raw and auxiliary materials, reducing environmental pollution, improving working conditions, and improving the comprehensive economic benefits of electric furnaces are of great value.
Ceramic materials made by using ceramics for special functions such as sound, light, electricity, magnetism, heat, etc. are called functional ceramics. There are many kinds of functional ceramics and their uses are different. Silicon carbide is mainly used as a mirror material in the field of functional ceramics. SiC ceramics have high specific stiffness, good thermal and chemical stability, low thermal deformation coefficient and space particle irradiation. Through special manufacturing processes, a lightweight mirror structure can be obtained.
The third generation of semiconductors is a key core material and electronic components supporting the innovation development and transformation and upgrading of the national defense armament, 5G mobile communication, energy Internet, new energy vehicles, rail transit, etc., because of its defense security, intelligent manufacturing, industrial upgrading, The important role of national major strategic needs such as energy conservation and emission reduction is becoming the technical commanding height of competition in all countries of the world.
As a typical representative of the third-generation semiconductor materials, SiC is one of the most mature and widely used wide-bandgap semiconductor materials in crystal production technology and device manufacturing. It has formed a global material, device and application industry chain. It is an ideal semiconductor material for high temperature, high frequency, radiation resistant, high power applications. Since silicon carbide power devices can significantly reduce the energy consumption of electronic devices, silicon carbide devices are also known as "green energy devices" that drive the "new energy revolution."
1. Semiconductor lighting field
Silicon carbide as the LED device substrate is the most mature field in its current application. A large proportion of SiC wafers are used in the market to manufacture high-brightness LED substrate materials. LEDs using silicon carbide as the substrate have higher brightness, lower power consumption, longer lifetime, and smaller unit chip area, which has great advantages in high-power LEDs.
2、New energy vehicles and uninterruptible power supplies, etc.
The new energy automotive industry requires inverter (ie motor-driven) semiconductor power modules that have far greater reliability than conventional industrial inverters when handling high-intensity currents; and better heat dissipation in high-current power modules. Strict, efficient, fast, high temperature, high reliability semiconductor silicon carbide modules fully meet the requirements of new energy vehicles. The miniaturization of semiconductor silicon carbide power modules can significantly reduce the power loss of new energy vehicles, so that they can still work normally at 200 °C. Lighter, smaller equipment reduces weight and reduces the energy consumption of the car's own weight.
In addition to occupying an important position in the energy-saving of new energy vehicles, semiconductor silicon carbide materials have played an outstanding role in energy conservation and environmental protection in high-speed rail, solar photovoltaic, wind energy, power transmission, UPS uninterruptible power supply and other power electronics fields.
3、make electronic devices smaller
Reduce the size of the laptop adapter by 80% and reduce the size of a substation to the size of a suitcase. This is also a place where silicon carbide semiconductors are expected. The development of silicon carbide technology is expected to reduce the size of consumer electronics, such as the size of laptop adapters by 80%; it is also possible to reduce the size of a substation to the size of a suitcase.
In addition to the above applications, silicon carbide whiskers or silicon carbide fibers as an excellent reinforcing and toughening agent, and metal-based or ceramic-based materials composite materials have also been widely used in machinery, chemicals, defense, energy, environmental protection and other fields.
