emery

Including black silicon carbide and silicon carbide green silicon carbide, including: Black silicon carbide is quartz sand, petroleum coke and high-quality silica as the main raw material, through high-temperature resistance furnace smelting made. The hardness between corundum and diamond, corundum higher mechanical strength, brittle and sharp. Green Silicon Carbide is a high-quality petroleum coke and silica as the main raw material, add salt as an additive, is made by smelting high-temperature resistance furnace. The hardness between corundum and diamond, corundum higher mechanical strength. Silicon carbide abrasive commonly used in two different crystals, one is green silicon carbide, with SiC 97% or more, gold is mainly used for grinding hard tool. The other is black silicon carbide, a metallic luster, containing SiC 95% more strength than a large green silicon carbide, but the hardness low, mainly used for grinding cast iron and non-metallic materials.

Formula for the SiC, the hardness between corundum and diamond, corundum higher mechanical strength can be used as abrasives and certain other industrial materials used. Industrial successful development of silicon carbide in 1891, was the first man-made abrasives. Although in the meteorite and the Earth's crust there is a small amount of silicon carbide, but has not yet been found for the exploitation of mineral resources.

Pure SiC is colorless and transparent crystal. Industrial silicon carbide due to the type and concentration of impurities in different, but was light yellow, green, blue and even black, transparency varies with its purity. SiC crystal structure is divided into hexagonal or rhombohedral of α-SiC and cubic β-SiC (called cubic silicon carbide). α-SiC crystal structure because of its carbon and silicon atoms form different stacking sequences of many different variants have been found more than 70 species. β-SiC at above 2100 ℃ into α-SiC.

Method for making silicon carbide industry is high-quality quartz sand and petroleum coke in the resistance furnace refining. Mixing silicon carbide blocks obtained by crushing, acid washing, magnetic separation and water screening or selection of products made of various size.

Green silicon carbide and silicon carbide, black silicon carbide two basic varieties commonly used, are of α-SiC. ① black silicon carbide SiC containing about 98.5%, higher than the toughness of the green silicon carbide, used mostly for processing the low tensile strength materials such as glass, ceramics, stone, refractory material, cast iron and non-ferrous metals. ② SiC99% or more with green silicon carbide, self sharpening, mostly for processing hard alloy, titanium alloy and optical glass, also used for honing cylinder liners and grinding high speed steel cutting tools. There are also cubic silicon carbide, which is a special process Preparation of yellow-green crystals, used to make super-abrasive finishing for bearings, make the surface roughness Ra32 ~ 0.16 microns from the first processing to Ra0.04 ~ 0.02 microns.