Uses of Silicon Carbide

Of the 700 000 tons SiC produced per year, about 33% is used in metallurgy as a deoxidizing plus alloying agent, and about 50% in the abrasive industry [257]. The remainder is used in the refractory and structural ceramics industries and to a small extent also in electric and electronic industries as heating elements, thermistors, varistors, light-emitting diodes, and attenuator material for microwave devices. 

Coated abrasives include abrasive paper and cloth in sheet or band form. They are produced by strewing the SiC grains onto a substrate coated with glue or bonding resin and then covering with a second layer of bonding agent [257], 

The addition of silicon carbide during the melting of cast iron aids carburization and siliconization, and improves the quality of the cast iron as a result of its seeding action [262], In the production of steel in an arc furnace, silicon carbide acts as deoxidant and helps in slag melting. 

The need to control thermal expansion and to increase the strength and Young modulus of aluminum alloys produced new Al-SiC composites alloys containing up to 50 vol-% SiC particles [263], The market is poised for rapid expansion in this area over the next years as developmental products move into commercialization stages. For reinforcement applications SiC is also used in the form of whiskers [264], platelets and fibres. 

The resistance of ceramically bonded and recrystallized silicon carbide to thermal shock, oxidation, and corrosion is utilized in its use as a refractory construction 

---

One of the first important uses of silicon carbide was as an abrasive (see Abrasives). Additional markets in refractories, electrical devices, and metallurgy have since been developed. In 1988, the silicon carbide market was estimated at 55% metallurgical, 43% abrasive, and 2% for refractories and... 

Brake linings -barite as filler [BARIUM COMPOUNDS] (Vol 3) -carbon fibers m [CARBON AND GRAPHITE FIBERS] (Vol 5) -mica m [MICA] (Vol 16) -use of silicon carbide [CARBIDES - SILICON CARBIDE] (Vol 4)... 

Gas igniters -use of silicon carbide [CARBIDES - SILICON CARBIDE] (Vol 4)... 

Some of the most common combinations used in the development of new ceramic composites involve the use of silicon carbide, silicon nitride, aluminum oxide, silicon dioxide, and mullite (a form of aluminum sulfate (Al2[S04]3). Each of these compounds can he used either as the reinforcement or as the matrix in a composite. 

The use of silicon carbide inserts has proved valuable in the uncatalyzed aza-Michael addition between piperazine and methyl acrylate. The reaction was low yielding using pure toluene as the solvent since the maximum temperature that could be attained was 170 °C. Adding the passive heating elements to the reaction mixture allowed for temperatures of 200 °C to be reached and, with this, a dramatic increase in the yield for the reaction was observed (Scheme 2.10). The product isolation procedure was trivial and consisted of physical removal of the heating element using a pair of tweezers followed by removal of the solvent. 

Due to its great hardness, heat resistance, and oxidation resistance, silicon carbide has become firmly established as an abrasive as well as a raw material for producing refractories such as firebricks, setter tiles, and heating elements. Another major use of silicon carbide is as a siliconizing and carburizing agent in iron and steel metallurgy. 

Predict the properties of silicon carbide (SiC). It has a giant covalent structure based on diamond. Find out about the uses of silicon carbide,... 

If grinding is required, the use of silicon carbide biurs is preferred, because wheels produce residues ofrubber or resin on the surface that contaminate the weld. Excessive heat shoiild be avoided while grinding and low rotating speeds shoiild be used. Soft-backed grinding tools shovild be used. 

---