The basic varieties of silicon carbide

Black silicon carbide and silicon carbide green silicon carbide two common basic varieties, are of α-SiC, SiC there are 75 kinds of variants, all of these structures can be divided into cubic, hexagonal and rhombohedral.
Wherein the α-SiC, β-SiC is most common. α-SiC is a high temperature stable, β-SiC is temperature stable. β-SiC at 2100 ~ 2400 ℃ can be transformed into α-SiC, β-SiC at about 1450 ℃ temperature by a simple mixture of silicon and carbon in the system.
Using transmission electron microscopy and X-ray diffraction techniques can be performed on the body of SiC polytypes microscopic analysis and quantitative determination of silicon carbide powder is mainly used for primary products and high heat ceramic materials in the field, is a high energy product, the country has been canceled silicon carbide powder 5% export tax rebates.
① black silicon carbide SiC containing approximately 98.5% higher than its toughness green silicon carbide, mostly for processing low tensile strength of the material, such as glass, ceramics, stone, refractory materials, cast iron and non-ferrous metals.
② green silicon carbide containing SiC99% or more, good self-sharpening, mostly used for machining tungsten carbide, titanium and optical glass, also used for honing cylinder liners and grinding high-speed steel cutting tools. There is also cubic silicon carbide, which is based on a special process to take the yellow-green crystals, suitable for the production of abrasive bearing super finishing, make the surface roughness Ra32 ~ 0.16 microns from primary processing to Ra0.04 ~ 0.02 microns.
Silicon carbide has four major application areas, namely: functional ceramics, advanced refractories, abrasives and metallurgical raw materials. Currently most enterprises are still in silicon carbide roughing state.