The industrial method of silicon carbide is to use high-quality quartz sand and petroleum coke to refine it in a resistance furnace. The smelted silicon carbide blocks are made into products of various particle sizes through crushing, acid-base washing, magnetic separation and sieving or water separation.
Silicon carbide has two commonly used basic varieties, black silicon carbide and green silicon carbide, both of which belong to α-SiC. ① Black silicon carbide contains about 98.5% SiC, and its toughness is higher than that of green silicon carbide. It is mostly used for processing materials with low tensile strength, such as glass, ceramics, stone, refractory materials, cast iron and non-ferrous metals. ②Green silicon carbide contains more than 99% SiC and has good self-sharpening properties. It is mostly used for processing hard alloys, titanium alloys and optical glass, and is also used for honing cylinder liners and fine grinding high-speed steel tools. In addition, there is cubic silicon carbide, which is a yellow-green crystal produced by a special process. The abrasive tools used to make it are suitable for superfinishing of bearings. The surface roughness can be processed from Ra32-0.16 micron to Ra0.04- 0.02 microns.
【 Use 】
(1) As an abrasive, it can be used to make abrasive tools, such as grinding wheels, oil stones, grinding heads, sand tiles, etc.
(2) As metallurgical deoxidizer and high temperature resistant material.
Silicon carbide mainly has four major application areas , namely: functional ceramics, advanced refractories, abrasives and metallurgical raw materials. At present, silicon carbide coarse material can be supplied in large quantities, which cannot be regarded as a high-tech product, and the application of nano-scale silicon carbide powder with extremely high technical content cannot form economies of scale in a short time.
(3) High-purity single crystals can be used to manufacture semiconductors and silicon carbide fibers.
( 4) Silicon carbide has great hardness and excellent thermal conductivity. It is a semiconductor and can resist oxidation at high temperatures
