Silicon carbide, an inorganic substance with the chemical formula SiC, is made from quartz sand, petroleum coke (or coal coke), wood chips (salt is added to produce green silicon carbide), and other raw materials smelted at high temperatures in resistance furnaces. Silicon carbide also exists in nature as a rare mineral, moissanite. Among C, N, B and other non-oxide high technology refractory raw materials, silicon carbide is the most widely used and economical one, which can be called gold steel sand or refractory sand. Industrial production of silicon carbide is divided into two kinds of black silicon carbide and green silicon carbide, both hexagonal crystals, specific gravity of 3.20 ~ 3.25, microhardness of 2840 ~ 3320kg/mm2.
History of Silicon Carbide
Silicon carbide is by the American Acheson in 1891 when the electric fusion diamond experiments, in the laboratory accidentally found a carbide, then mistaken for a mixture of diamond, so named adamantine, 1893 Acheson research out of the industrial smelting silicon carbide method, which is often referred to as Acheson furnace, has been used to this day, to carbon material for the core body of the resistance furnace, electric heating quartz SiO2 and a mixture of carbon to produce silicon carbide.
Classification of Silicon Carbide
Black silicon carbide
Black silicon carbide contains about 95% SiC, its toughness is higher than green silicon carbide, and it is mostly used for processing materials with low tensile strength, such as glass, ceramics, stone, refractory materials, cast iron and non-ferrous metals.
Green Silicon Carbide
Green silicon carbide contains about 97% SiC or more, good self-sharpening, mostly used for processing carbide, titanium alloy and optical glass, also used for honing cylinder liners and fine grinding high-speed steel tools. In addition, there is also cubic silicon carbide, which is a yellow-green crystal made by a special process, used to make abrasives suitable for bearing super-finish machining, can make the surface roughness from Ra32 ~ 0.16 microns to Ra0.04 ~ 0.02 microns at a time.
Silicon carbide material structure
Pure silicon carbide is a colorless and transparent crystal. Industrial silicon carbide is light yellow, green, blue or even black depending on the type and content of the impurities it contains, and its transparency varies with its purity. The crystal structure of silicon carbide is divided into α-SiC, which is hexagonal or rhombic, and β-SiC, which is cubic (called cubic silicon carbide). α-SiC is composed of many different variants due to the different stacking sequences of carbon and silicon atoms in its crystal structure, and more than 70 types have been found. β-SiC is transformed into α-SiC at 2100°C and above. Refining. The refined silicon carbide blocks are crushed, washed with acid and alkali, magnetically separated and sieved or water-selected to make products of various particle sizes.
Silicon Carbide Manufacturing Process
Due to its low natural content, silicon carbide is mostly man-made. The common method is to mix quartz sand with coke, using the silica and petroleum coke in it, adding salt and wood chips, placing it in an electric furnace, heating it to a high temperature of about 2000°C, and then obtaining silicon carbide powder after various chemical processes.
Silicon Carbide Applications
It is mainly used for making grinding wheels, sandpaper, abrasive belts, oil stones, grinding blocks, grinding heads, abrasive pastes and for grinding and polishing of monocrystalline silicon, polycrystalline silicon in photovoltaic products and piezoelectric crystals in the electronics industry, etc.
Using silicon carbide with corrosion resistance, high temperature resistance, high strength, good thermal conductivity, impact resistance and other characteristics, silicon carbide on the one hand can be used for a variety of smelting furnace lining, high-temperature kiln components, silicon carbide plate, liner, support parts, sagger, silicon carbide crucible, etc..
On the other hand, it can be used for high temperature indirect heating materials in non-ferrous metal smelting industry, such as vertical tank distillation furnace, distillation furnace tower plate, aluminum electrolytic tank, copper melting furnace lining, zinc powder furnace with arc plate, thermocouple protection tube, etc.; it is used to make wear-resistant, corrosion-resistant, high temperature resistant and other advanced silicon carbide ceramic materials; it can also make rocket nozzle, gas turbine blades, etc. In addition, silicon carbide is also one of the ideal materials for highways, aerospace runways, solar water heaters, etc.
The hardness of silicon carbide is second only to diamond, with strong wear resistance, is the ideal material for wear-resistant pipes, impellers, pump chambers, cyclones, hopper linings, and its wear resistance is 5-20 times that of cast iron. Its wear resistance is 5-20 times that of cast iron and rubber, and it is also one of the ideal materials for aviation runways.
SiC ceramics not only have excellent room temperature mechanical properties, such as high flexural strength, excellent oxidation resistance, good corrosion resistance, high wear resistance and low coefficient of friction, but also high temperature mechanical properties (strength, creep resistance, etc.) are widely used in various ceramic materials.
Silicon Carbide Manufacturer
Henan Superior Abrasives Import & Export Co., Ltd. (HSA), established in 2001, is a leading supplier of silicon carbide and related products in China. As a crucial supplier of abrasive products, HSA maintains close contact and strategic cooperation with many famous multinational corporations. Our market covers America, Canada, Mid-east, Russia, Spain, South Africa, Southeast Asia and etc.
If you have a need for silicon carbide, welcome to contact us!