Formule chimique du carbure de silicium

Silicon Carbide (SiC) is an extremely hard and synthetically produced crystalline compound of silicon and carbon, popularly referred to as carborundum.

Mohs hardness rating of 9 makes it similar to diamond and it can be used as an abrasive and in refractory products such as furnace linings.

Silicon is another material with great potential for high-power applications, offering numerous polytypes with different crystalline structures.

Chemical Formula

Silicon carbide (SiC) is a synthetically produced and extremely hard crystalline compound of silicon and carbon with the chemical formula SiC. First discovered naturally by Henri Moissan at Devil’s Canyon, Arizona and later synthesized using electric heat by American inventor Edward Acheson in 1891 using finely ground silicon atoms fused together with carbon atoms – this process now used to make industrial abrasives such as sandpaper and grinding wheels; additionally used refractory linings for furnaces; used extensively by semiconductor electronics requiring high temperatures or voltages; naturally present as moissanite.

Silicon carbide has an endothermic standard enthalpy change per mole of 1124.9 kJ/mol, an extremely positive value and indicative of an exothermic reaction. Silicon Carbide can be produced using various processes; one common way involves mixing pure silica sand (SiO2) with coke in an electric arc furnace at high temperatures to form blocks of silicon carbide which are crushed down further and refined further via crushing, acid-base washing, magnetic separation sieving or water separation techniques.

Pure silicon carbide has a colorless density of 3.21 g/cm3 and sublimates at 2700 degC; its insoluble in water. In practice however, due to impurities present during industrial production of silicon carbide (such as iron or other trace elements), yellow to green to bluish black iridescent crystals usually form. Silicon carbide acts as an electrical insulator in its purest forms but by doping with nitrogen or phosphorus it can be made n-type, while beryllium or aluminum can turn it p-type and produce semiconductor properties in semiconductor applications.

There are more than 250 crystalline structures of silicon carbide, defined by their stacking arrangement of silicon and carbon atoms. These polytypes of silicon carbide vary in their brittleness, hardness, resistance to chemical reactions and ductility – from diamond-like rhombic stellate (known as 3/SiC) being extremely hard and brittle to the more ductile glassy amorphous shape known as 2/SiC.

Propriétés physiques

Silicon carbide (SiC) is an industrial mineral crystalline material that functions both as ceramic and semiconductor properties. Known for its combination of hardness and strength, SiC’s other physical properties make it suitable for many high-temperature, abrasive applications including grinding media for metals grinding applications as well as furnace refractories, cutting tools, sandpapers, jet engine parts and LED light bulb substrate substrate applications. SiC is frequently employed in these roles.

SiC is an inorganic compound composed of silicon and carbon with a Mohs scale rating of 9. It forms grey to brown solids that belong to the carbide group of minerals; natural forms include moissanite. Pure SiC forms colorless crystals while impurities such as nitrogen or aluminum produce green or blue hues in its crystal form.

Due to its extreme hardness, chemical inertness and low thermal expansion coefficient, polycarbonate plastic is highly resistant to corrosion. With temperatures reaching up to 1400 deg C without loss in mechanical strength – making it an excellent material choice for components that must operate in harsh environments, such as heat exchangers and flame igniters.

Silicon Carbide can be produced through several processes that produce a wide range of internal and external microstructures, typically variations in stoichiometry. Most commonly seen are hexagonal tetrahedral (a-SiC) and cubic structures (b-SiC), though polytypes derived from them can also be combined to achieve different physical and electrical properties.

Silicon carbide’s chemical bond between Si and C forms strong covalent tetrahedral bonds that make for strong covalent bonds between each tetrahedron, linking and stacking them in polar structures that give this material its electrical properties. Silicon carbide itself acts as an excellent insulator but, with some careful doping or introduction of impurities or dopants, can express semi-conductor properties; neither allowing free current flow nor completely repelling it like alumina or boron carbide thus creating a middle ground between them two which has made silicon carbide an invaluable asset when used for space exploration applications as well as deep oil and gas extraction applications. This material has proven its use across a number of challenging space exploration projects as well as deep oil and gas extraction applications around the world.

Propriétés mécaniques

Silicon carbide, a non-oxide ceramic material, is one of the hardest, strongest, and most advanced materials used in products like abrasives, refractories, ceramics and others. Due to its wider bandgap it also finds use in electronic components.

Edward Acheson made history when he artificially synthesized diamond powder for industrial abrasives in 1891 by discovering small black crystals in an electrically heated melt of carbon and alumina. Acheson ground these crystals into powder for use as industrial abrasives. Acheson’s discovery was verified by Nobel prize-winning chemist Henri Moissan when in 1905 he discovered transparent forms of it, known as moissanite mineral, within a Canyon Diablo meteorite located in Arizona.

Silicon carbide is currently created by heating alumina and silica together at high temperatures under controlled environments, then shaping into blocks or pellets for use in various industrial applications. Silicon carbide’s ultrahard surface makes it useful for grinding, cutting, drilling and milling while its thermal conductivity provides great thermal conductivity while its chemical resistance provides exceptional chemical resistance.

Silicon carbide’s properties have made it ideal for use in large astronomical telescopes and spacecraft subsystems, including mirrors. Due to its rigidity and low coefficient of thermal expansion it makes an excellent base material as it will not expand or contract when temperatures fluctuate.

Excellent abrasion and impact resistance make ceramic an excellent material for wear applications like grinding wheels and shot blast nozzles, while its strength also makes it suitable for refractory and ceramic components such as furnace liners and wear-resistant coatings.

Silicon carbide’s wide bandgap allows it to conduct electricity more efficiently than other semiconductors, as electrons require less energy to transition from its valence band into its conduction band. Furthermore, this efficiency boost helps it better handle higher voltages and frequencies than competing materials since its larger energy gap allows more electrons to move at once.

Propriétés électriques

Silicon carbide possesses unique electrical properties that enable it to perform in numerous high-performance circuitry applications. When in its pure state, silicon carbide acts as an electrical insulator; however, adding small amounts of impurities – specifically aluminium doping – allows it to express semiconductor properties. In particular, doping aluminium creates a p-type semiconductor material.

Wide band-gap semiconductor properties are especially beneficial in applications requiring high voltages, such as power electronics and other power applications. These semiconductors can withstand ten times greater breakdown electric field strength than regular silicon semiconductors, making them suitable for devices exposed to extreme voltage levels.

SiC stands out as an attractive material due to its superior resistance to current flow than that found in silicon at equivalent voltage, significantly decreasing energy lost to heat within devices and eliminating the need for costly active cooling systems which add weight, complexity and cost to a product.

Silicon carbide’s low thermal expansion makes it a desirable mirror material for large astronomical telescopes, where it can be grown into disks up to 3.5 m (11 feet). Furthermore, due to its durability, rigidity and excellent thermal conductivity it makes an excellent base material for electronic components in environments where vibrations may cause damage.

Silicon is still the go-to semiconductor material in modern electronics, yet its high power applications are beginning to show its limits. Silicon carbide offers several advantages that address these shortcomings, including its wide band-gap semiconductor property – defined as the energy required to free an electron from orbit around a nucleus; measured in electron volts or eV. Silicon carbide has an electron volt value that is almost three times that of standard silicon.

Silicon carbide occurs naturally as the ultra-rare mineral moissanite, typically found in minute quantities within meteorites, corundum deposits and kimberlite. Since 1893 it has been commercially manufactured as powder form for use as an abrasive, frequently being combined with other grains to create hard ceramics that form very hard ceramics bonded together with each grain to form tough durable compounds such as brakes and clutches for car brakes and clutches as well as ceramic plates used on bulletproof vests and light emitting diodes as detectors in early radios.

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