The industrial manufacturing method of silicon carbide is to use high-quality quartz sand and petroleum coke to be refined in a resistance furnace. The refined silicon carbide blocks are crushed, washed with acid and alkali, magnetic separation, sieving or water selection to produce products of various particle sizes.
Silicon carbide abrasives have two common basic varieties, black silicon carbide and green silicon carbide, both of which belong to α-SiC.
①Black silicon carbide in silicon carbide abrasives contains about 98.5% of SiC, and its toughness is higher than that of green silicon carbide. It is mostly used to process materials with low tensile strength, such as glass, ceramics, stone, refractory materials, cast iron and non-ferrous metals.
②The green silicon carbide in the silicon carbide abrasive contains more than 99% SiC and has good self-sharpening properties. It is mostly used for processing cemented carbide, titanium alloy and optical glass, as well as for honing cylinder liners and fine grinding high-speed steel tools.
In addition, there is cubic silicon carbide, which is a yellow-green crystal prepared by a special process. The abrasive tool used for making is suitable for the super finishing of the bearing. The surface roughness can be processed from Ra32～0.16 microns to Ra0.04～0.02 microns.
Silicon carbide abrasives have stable chemical properties, high thermal conductivity, low thermal expansion coefficient, and good wear resistance. In addition to being used as abrasives, there are many other uses.
For example: coating silicon carbide abrasive powder on the inner wall of the turbine impeller or cylinder block with a special process can improve its wear resistance and prolong its service life by 1 to 2 times; the high-grade refractory used to make it is resistant to shock, with small size, light weight, high strength, and good energy-saving effect. Low-grade silicon carbide is an excellent deoxidizer, it can speed up the steelmaking speed, and facilitate the control of chemical composition, improve the quality of steel. In addition, silicon carbide is also widely used to make silicon carbide rods for electric heating elements.
Silicon carbide abrasive has high hardness and excellent thermal conductivity. It is a semiconductor and can resist oxidation at high temperatures.