Due to its super hard properties, it can be prepared into various grinding wheels, abrasive cloths, sandpaper and various abrasives, which are widely used in the mechanical processing industry.
The abrasives made of black silicon carbide are mostly used for cutting and grinding materials with low tensile strength, such as glass, ceramics, stone and refractory, etc. They are also used for the grinding of cast iron parts and non-ferrous metal materials.
Green silicon carbide abrasives are mostly used for grinding carbide, titanium alloy and optical glass, as well as for honing cylinder liners and fine grinding of high-speed steel tools. Cubic silicon carbide is specially used for super-finish grinding of micro-bearings. The oil stone made of W3.5 cubic silicon carbide micro-powder is used for super-finish grinding of bearings (material ZGCr15), and its finish can be directly ground from A9 to more than A12. Therefore, among other abrasives of the same grain size, cubic silicon carbide has the highest processing efficiency.
The number of foreign countries using silicon carbide as a refractory material is greater than the number of abrasives. China is also expanding the application of this area, according to the habits of foreign manufacturers, refractory materials black silicon carbide is usually divided into three kinds of grades:
① Advanced refractory black silicon carbide. The chemical composition requirements of this grade are exactly the same as those of abrasive black silicon carbide, which is mainly used to manufacture advanced silicon carbide products, such as recrystallized silicon carbide products, gas turbine component nozzles, silicon nitride combined with silicon carbide parts, blast furnace high-temperature zone lining materials, high-temperature kiln components, high-temperature kiln support parts, refractory saggars, etc.
②Secondary refractory material black silicon carbide, containing more than 90% silicon carbide. Mainly used in the manufacture of medium high temperature resistant kiln components, such as muffle furnace lining materials. These components in addition to the use of silicon carbide heat resistance, thermal conductivity, in many cases also use its chemical stability.
③ Low-grade refractory material black silicon carbide, its silicon carbide content required more than 83 %, mainly used in the lining of the iron tank, iron ladle, zinc and sponge iron manufacturing industry, etc.
Steelmaking usually use ferrosilicon deoxidation, the recent development of silicon carbide instead of ferrosilicon as a deoxidizer, the steel quality is better, more economical. Because the use of silicon carbide deoxidation, into less slag and quickly, effectively reducing the content of some useful elements in the slag, steelmaking time is short and better control of the composition.
Deoxidizer black silicon carbide in the United States and Japan and other countries in the steel industry is used very commonly. Abrasive or refractory materials with silicon carbide in the furnace generated by the material suitable for deoxidizer, can all be sold and applied to the production without the need to return to the furnace, the product comprehensive utilization rate is high, the economic effect of silicon carbide production is excellent.
Wear-resistant and high-temperature parts
The use of silicon carbide ceramic high hardness, wear resistance, acid and alkali corrosion resistance, in the mechanical industry, the chemical industry used to prepare a new generation of mechanical sealing materials, sliding bearings, corrosion-resistant pipes, valve blades and fan blades. Especially as a mechanical seal material has been internationally recognized as the fourth generation of basic materials since the metal, alumina carbide, its acid resistance, alkali resistance compared with other materials is extremely good, almost no material can be compared with it.
Using the high thermal conductivity of silicon carbide ceramics, it can be used for high-temperature heat exchangers in metallurgical furnaces, etc., and the temperature can reach 1300℃; grinding rice with silicon carbide sand rollers can improve the quality of rice compared with other sand rollers, and the rice yield can be increased by 1%~2%, and the cost can be reduced by 30%~40%. Using electroplating method to silicon carbide micropowder coating on the turbine leaves, can greatly improve the wear resistance of the impeller, extending its maintenance cycle. Using mechanical pressure to press cubic silicon carbide grinding powder and W28 micro powder into the cylinder wall of internal combustion engines can extend the service life of the cylinder block by more than one time.
The use of silicon carbide and borax mixture of 45# steel harvester blade surface boron chemical heat treatment, can make its boron layer of hardness to reach the microhardness of 1800 ~ 2000 grams, thus extending its service life several times.
Rollers made of silicon carbide have long been successfully used in steel rolling mills, which have better heat resistance and wear resistance than metal rollers, and can improve the quality of the rolled steel. The sand pump and hydrocyclone made of silicon carbide material have good wear resistance; the cylinder liner made of silicon carbide material and other wear-resistant parts can be widely used in petroleum and chemical industry machinery; it can also be used as high-temperature thermal machinery materials. Silicon carbide has good high temperature characteristics, such as high temperature oxidation, high temperature strength, creep, good thermal conductivity and low density, is preferred for high temperature parts of thermal machinery, such as: for high temperature combustion turbine combustion chamber, turbine static blade high temperature nozzle, etc.. Made of silicon carbide piston and cylinder liner for non-lubricant non-cooling diesel engine, can reduce friction 30% ~ 50%, noise significantly reduced.
With silicon carbide ceramics and other materials together with the composition of the combustion chamber and nozzle, has been used in rocket technology. Silicon carbide-based composite materials prepared by the Ariane rocket tail nozzle has been successfully applied. Silicon carbide density in the middle, 20% lighter than Al2O3, hardness and elastic modulus is high, the price is much lower than B4C, but also can be used in armored vehicles and aircraft belly and bulletproof and stab-proof vest, etc.. Silicon carbide material also has self-lubricating and small coefficient of friction, about half of that of cemented carbide. Its good thermal shock resistance, high modulus of elasticity and other characteristics in some special places to be applied, such as used to make high-power laser mirrors whose performance is better than copper, due to low density, good rigidity, small deformation, CVD and reaction sintering of silicon carbide lightweight mirrors have been used in space technology in large quantities.
Electrical and electrotechnical
The use of silicon carbide ceramic high thermal conductivity, good insulation as the substrate of large-scale integrated circuits and packaging materials silicon carbide heating body is a commonly used heating element, because it has the advantages of simple and convenient operation, long service life, wide range of use, etc., become the most durable and inexpensive heating materials, the use of temperature up to 1600 ℃. Silicon carbide can also be used to do lightning arrester valve body and far infrared generator, etc.