Shandong Huayi Kechuang Nanomaterial Co.Ltd.

Silicon carbide is also called llic steel sand or refractory sand. Silicon carbide is made from quartz sand, petroleum coke (or coal coke), wood chips (salt is needed to produce green silicon carbide) and other raw materials after high temperature smelting in the resistance furnace. At present, the industrial silicon carbide produced in China is divided into black silicon carbide and green silicon carbide, both of which are hexagonal crystals with a specific gravity of 3.20 ~ 3.25 and a microhardness of 2840 ~ 3320kg/mm2.
Including black silicon carbide and green silicon carbide, including: black silicon carbide is quartz sand, petroleum coke and high-quality silicon as the main raw material, through resistance furnace high temperature smelting. Its hardness is between corundum and diamond, mechanical strength is higher than corundum, brittle and sharp. Green silicon carbide is made from petroleum coke and high-quality silica as the main raw materials, salt as the additive, through resistance furnace high temperature smelting. Its hardness is between corundum and diamond, and its mechanical strength is higher than that of corundum. Commonly used silicon carbide abrasives have two different crystals, one is green silicon carbide, containing SiC more than 97%, mainly used for grinding hard gold-bearing tools. The other is black silicon carbide, llic luster, containing more than 95% SiC, strength than green silicon carbide, but low hardness, mainly used for grinding cast iron and non-llic materials.
The molecular formula is SiC, whose hardness is between corundum and diamond, and its mechanical strength is higher than that of corundum, which can be used as abrasive and some other industrial materials. Silicon carbide for industrial use was successfully developed in 1891 and was the earliest artificial abrasive. Although there is a small amount of silicon carbide in meteorites and the earth's crust, so far no mineral source has been found for exploitation.
Pure silicon carbide is a colorless transparent crystal. Industrial silicon carbide is light yellow, green, blue and black due to the variety and content of impurities, and its transparency varies with its purity. Silicon carbide crystal structure is divided into hexagon or rhombohedral alpha -SiC and cubic beta -SiC(called cubic silicon carbide). More than 70 kinds of alpha-sic have been found due to the different stacking sequences of carbon and silicon atoms in the crystal structure. Beta SiC at above 2100 ℃ into alpha SiC.
The industrial process of silicon carbide is made by refining fine quartz sand and petroleum coke in a resistance furnace. Refined silicon carbide blocks, by crushing, acid and alkali washing, magnetic separation and screening or water separation and made of a variety of particle size products.
Silicon carbide has black silicon carbide and green silicon carbide two common basic varieties, both belong to alpha-sic. (1) black silicon carbide contains SiC about 98.5%, its toughness is higher than green silicon carbide, mostly used for processing materials with low tensile strength, such as glass, ceramics, stone, refractories, cast iron and non-ferrous ls. Green silicon carbide contains SiC99 % more than, self-sharpening is good, mostly used for processing hard alloy, titanium alloy and optical glass, also used for honing cylinder sleeve and fine grinding high-speed steel tool. In addition, there is cubic silicon carbide, which is a yellow-green crystal made by a special process. The grinding tool used to make it is suitable for ultra-fine machining of bearings, so that the surface roughness can be processed from Ra32 ~ 0.16 micron to Ra0.04 ~ 0.02 micron at a time.
Silicon carbide due to its stable chemical properties, high thermal conductivity, small thermal expansion coefficient, good wear resistance, in addition to abrasive, there are many other USES, such as: special process of silicon carbide powder coating on the inner wall of the turbine impeller or cylinder body, can improve its wear resistance and extend the service life of 1 ~ 2 times; It is used to make high grade refractory, heat shock, small size, light weight and high strength, good energy saving effect. Low grade silicon carbide (containing SiC about 85%) is an excellent deoxidizer, which can accelerate the speed of steel making, facilitate the control of chemical composition, and improve the quality of steel. In addition, silicon carbide is also widely used in the production of electric heating element silicon carbon bar.
Silicon carbide is a kind of semiconductor with high hardness and excellent thermal conductivity. It can resist oxidation at high temperature.
[purpose] (1) as an abrasive, it can be used as a grinding tool, such as grinding wheel, whetstone, grinding head, sand tile, etc. (2) as llurgical deoxidizer and high temperature resistant material.
Silicon carbide mainly has four application fields, namely: functional ceramics, advanced refractories, abrasives and llurgical raw materials. At present, silicon carbide raw material can be supplied in large quantities, which is not considered as a high-tech product. However, the application of nanometer silicon carbide powder with very high technical content is unlikely to form economies of scale in a short time.

Silicon carbide main purpose