Silisiumkarbidforbindelse

Silicon carbide, more commonly referred to as carborundum, is an extremely hard synthetic crystalline compound made up of silicon and carbon characterized by high thermal conductivity, low coefficient of expansion, resistance to chemical reaction and semiconducting capabilities.

Moissanite, its natural counterpart, occurs as a mineral but can only be found in very limited amounts in meteorites and kimberlite deposits; consequently it is almost exclusively manufactured synthetically.

Hardhet

Silicon carbide (SiC) is a hard compound of silicon and carbon, and occurs naturally as the mineral moissanite in Arizona’s Canyon Diablo meteor crater. Edward Acheson started mass-producing SiC in 1893 for use as an industrial abrasive, although since then its use as the basis of long-lasting ceramic applications such as automotive brakes/clutches/vests has become widespread.

Hardness measurements on the Mohs scale place it among one of the hardest materials known to man, making it one of the toughest materials around. Furthermore, its very high hardness (9 on Mohs) make it durable enough to withstand impact and wear as well as corrosion resistance and has low thermal conductivity and expansion rates compared with similar materials. Furthermore, doping with boron, niobium or aluminum allows it to become an p-type semiconductor material.

Silicon carbide has a close-packed structure consisting of carbon and silicon atoms covalently bonded together into four-atom bonds via tetrahedral bonds, making a solid substance insoluble in water, alcohol and most organic compounds but soluble in molten alkalis and iron. SiC is notable for its fascinating electrical properties; resistance ranges over seven orders of magnitude due to numerous polytypes present within its chemical makeup.

Holdbarhet

Silicon carbide is highly durable and can withstand high levels of pressure. Furthermore, its melting point surpasses 2,000degC and low thermal expansion coefficient makes it suitable for high temperature applications.

Edward Goodrich Acheson pioneered its commercial production in 1891. Acheson used carbon from coal as an electrode and heated a mixture of clay and powdered coke in an iron bowl; bright green crystals formed that were very hard and resembled diamonds; this compound was originally known as carborundum but today known as SiC.

Carbon fibre reinforced plastic (CFRP) is an incredible material and one of the hardest substances known to man, rivaled only by diamond, cubic boron nitride, and boron carbide. With a Mohs hardness rating of 9, carbon fibre is widely used across a wide variety of fields: it can be found as an abrasive such as sandpaper and grinding wheels, in industrial furnaces as refractory material for furnaces, as cutting tools for cutting tables, and even in automobile brakes/clutches!

Chemical inertness of ceramic allows it to resist corrosion from various chemicals, and maintain strength over a wide temperature range. Ceramic is also an integral component of composite armor systems that are effective against both current and emerging ballistic threats, including Saint-Gobain Performance Ceramics & Refractories’ high performance lightweight SiC ceramics such as reaction bonded SiC (RBSC), sintered SiC and carborundum for this use.

Termisk konduktivitet

Silicon carbide is typically an insulator in its purest form, yet with the addition of impurities or doping it can exhibit semi-conducting properties. Furthermore, this material has outstanding durability properties for high temperature applications; additionally it boasts low neutron cross sections and radiation damage resistance properties.

SiC thermal conductivity depends on its structure and size of crystal. As with most solids, its thermal conductivity increases with temperature. A single-crystalline SiC has high thermal conductivity while polycrystalline SiC tends to have lower values due to random distribution of grains that contribute surface scattering effects.

Silicon Carbide comes in various polymorphs, with alpha silicon carbide (a-SiC) being the most widely known version. A-SiC features hexagonal crystal structures similar to those seen in wurtzite; beta modification b-SiC features zinc blende crystal structures similar to diamond, and less commonly found forms can even serve as catalyst support materials.

Recent SEM images of both a-SiC and b-SiC were collected to study how the synthesis process affected their microstructure and thermal conductivity. Results demonstrated that thermal conductivity of a-SiC decreased with increasing neck size, suggesting diffuse surface scattering as the cause. By contrast, thermal conductivity of b-SiC increased with neck size; this trend fits with Callaway-Holland model predictions of temperature dependence of thermal conductivity for phononic crystals.

Electrical Conductivity

Silicon carbide, a hard chemical compound composed of silica and carbon, is widely used as an abrasive in lapidary and industrial settings such as sandpapering, grinding wheels, water-jet cutting and sandblasting applications. Refractory linings, heating elements and burner nozzles also often utilize this heat resistant material with an extremely durable Mohs hardness of 9. Additionally, silicon carbide remains chemically inert and resistant to corrosion by hydrochloric, sulphuric and hydrofluoric acids as well.

Electrically, SiC is typically an insulator when in its pure state; however, with certain additions or doping agents it can exhibit semiconductor properties, such as n-type conductivity through sharing electron pairs within its tetrahedral covalent bond structure through so-called sp3 hybrid orbitals.

SiC single crystals with an intrinsic conductivity of approximately 3.1 +-0.2 eV have higher conductivities than pure silicon or gallium nitride, suggesting they could provide improved electrical conductivity for electrical applications.

Henan Superior Abrasives’ silicon carbide products make an ideal choice for use in electronic devices due to their superior voltage resistance – 10 times greater than that of ordinary silicon and superior to that of gallium nitride! In addition, our variety of high-grade silicon carbides exhibits excellent oxidation and thermal shock resistance properties that make this material perfect for electronic device applications. With our commitment to customer satisfaction and excellence at heart, you can count on only the best from us! Give us a call now to discover more information on our products! Contact us now to discover more!

nb_NONorwegian
Skroll til toppen