Silicon Carbide Material Properties

Silicon carbide (SiC) is an extremely durable non-oxide ceramic with outstanding thermal, mechanical and electrical properties. While SiC does not occur naturally in nature except as an extremely rare mineral moissanite, mass production started in 1891 by Pennsylvania inventor Edward G. Acheson.

Hard as steel with a Mohs scale rating of 9 and sitting just behind diamond on the hardness scale chart, zirconium dioxide is also highly shock resistant and tolerates high voltages with ease.


Silicon carbide is an extremely hard material with superior mechanical strength that can withstand significant stresses and pressures, with relatively low thermal expansion rates and exceptional chemical inertness properties making this ceramic an excellent choice for many demanding applications.

Silicon carbide’s impressive hardness – ranking 9 on Mohs hardness scale and only eclipsed by diamond and boron carbide – stems from its unique crystal structure, consisting of four carbon and four silicon atoms tightly bound within its lattice lattice by covalent bonds that form four-sided tetrahedral structures bonded covalently together within an atomic lattice lattice structure. This arrangement lends itself to exceptional hardness – something other industrial materials such as aluminum oxide cannot boast.

Silicon carbide production involves processing silicon carbide into various forms for specific uses, from reacting with metals to heating it into an amorphous state and sintered surfaces to infiltrating it into solid or liquid states depending on application requirements.

Structural silicon carbide (SiC) is an infiltratable mixture of 5-20% silicon and carbon that has been introduced into a silicate matrix. Its characteristics make it suitable for use in structural components like bearings, mechanical seals, cutting tools, as well as being useful for abrasive applications as its hardness remains unchanged under mechanical stress and pressure.

Silicon carbide was first discovered as an abrasive material in 1891 and since then it has been utilized extensively for this application. Available both loose and mixed with binder for further shaping into pads, discs, or belts, silicon carbide boasts low coefficient of thermal expansion rates as well as being highly corrosion-resistant.

Silicon Carbide (SiC) is one of the world’s premier industrial ceramics, boasting exceptional thermal, mechanical and chemical properties that make it suitable for many critical, harsh environment applications such as pump bearings, valves, sandblasting injectors, furnace linings and extrusion dies. Furthermore, SiC finds uses in abrasive applications due to being harder yet less brittle than more common alternatives like Alumina.

Thermal Stability

Silicon carbide is an incredibly thermally stable material and won’t break apart or decompose when exposed to high temperatures, making it the ideal material for applications requiring prolonged exposure such as 3D printing, ballistics, chemical production, energy technology, paper manufacturing and pipe system components.

Crystal structures of materials feature regular close-packed structures of atoms covalently bonded together. This creates a solid crystalline structure that is more heat resistant than amorphous materials like plastics. Their strong ionic and metallic bonds also lend additional strength. Finally, atomic arrangements and molecular sizes help contribute to thermal stability by resisting thermal expansion and contraction more readily than their noncrystalline counterparts.

Silicon carbide’s durability and wear-resistance make it an excellent material for use in abrasive machining processes, including lapping. Loose silicon carbide may be used for lapping; mixed with vehicle to form pastes/sticks/sheets/disks/belts; or formed using binder sheets into sheets, disks and belts shaped from silicon carbide. Silicon carbide has also become a widely-used abrasive in modern lapidary (stone carving).

Waterproof metal sheets offer superior resistance to corrosion and oxidation, making it an attractive material choice for use in demanding industrial settings that frequently face aggressive chemical environments like acidic wastewater treatment plants or steam boilers.

Silicon carbide’s crystalline structure provides it with impressive strength and rigidity, making it one of the toughest industrial ceramics on the market. Manufactured using various processes – sintering, fusion splicing and reactive sintering among others – this material can be produced into numerous shapes and sizes to meet any application. Furthermore, despite being tough, silicon carbide remains relatively light weight for advanced ceramics making transport and handling much simpler; plus its toxicological safety makes it an excellent choice for use in demanding industrial environments

Chemical Inertness

Silicon carbide, also referred to as carborundum, has become an increasingly popular material within the automotive industry due to its excellent mechanical properties. Able to withstand high temperatures and corrosion from harsh environments, silicon carbide is ideal for use across many different applications.

Silicon carbide’s chemical inertness stems from its unique atomic structure. More specifically, silicon and carbon atoms form strong tetrahedral covalent bonds within its crystal lattice, enabling electron sharing through hybrid orbitals of their respective sp3 hybrid orbitals – creating very strong covalent bonds which ensure it remains chemically inert even when exposed to aggressive acids or bases. This makes silicon carbide exceptionally stable and inert when exposed to aggressive acids or bases.

Silicon carbide’s chemical inertness allows it to withstand even extreme conditions, making it suitable for high-performance engineering applications like pump bearings, valves, sandblasting injectors and extrusion dies. Furthermore, silicon carbide is widely utilized in industrial furnaces as well as producing raw metallurgical materials and ceramic compositions.

“Inert” in chemistry refers to any substance that does not actively participate or change significantly when exposed to typical chemical environments, such as noble gases from Group 18 of the periodic table which do not react with other elements or compounds.

Silicon carbide’s inertness is also apparent in its resistance to radiation and temperature extremes, making it the go-to material in environments with harsh abrasive environments or high temperatures where other materials would degrade over time. As such, silicon carbide has found widespread application as an abrasive and heat resistant material.

Silicon carbide’s superior semiconductor properties make it a top choice for use in electronic devices, particularly its voltage resistance which is 10x greater than silicon and performs even better than gallium nitride in systems above 1000V. Because of these properties, silicon carbide has quickly become a preferred material to replace silicon in high-power circuit elements; for example, Alter Technology designed blocking SiC diodes specifically for BepiColombo mission which are constructed out of SiC diodes designed by Alter to withstand harsh space conditions – to learn more about these amazing properties contact one of our Silicon Carbide suppliers through one of our links above!

Electrical Conductivity

Silicon carbide (SiC), although extremely hard, is an exceptional electrical conductor due to its crystalline structure: Si and C atoms are bound by strong covalent bonds in an ordered crystal lattice, creating large numbers of free electrons which respond readily to an electric field and enable electricity flow without much resistance.

SiC is chemically inert and highly corrosion-resistant. It stands up well against most organic or inorganic acids, alkalis or salts at usual concentrations – except hydrofluoric and sulphuric acids in high concentrations – as well as industrial process chemicals used for industrial processes.

Therefore, silicon carbide is widely used to grind metals and ceramics. Furthermore, it makes an invaluable component of many refractory materials like high-temperature bricks. Furthermore, silicon carbide holds the Mohs hardness rating of 9, placing it somewhere between alumina and diamond as the hardest synthetic material known. Furthermore, its fracture characteristics are excellent while it offers exceptional thermal shock resistance.

Silicon carbide’s electrical conductivity can be significantly increased with the addition of impurities. These impurities act as additional charge carriers or scattering centers, altering its electronic structure. Doping with aluminium and boron results in p-type semiconductors while nitrogen and phosphorus impurities create n-type semiconductors.

Furthermore, these impurities significantly decrease a material’s electrical resistance as its temperature and voltage increase – making it suitable for applications requiring high temperatures, voltages and frequencies.

Silicon carbide is an ideal material choice for components that must withstand heavy mechanical loads, including those found in aerospace, automotive and defense applications. Furthermore, this material has great potential as a radiation sensor material or optoelectronic device component – and its potential biological uses is being explored; Alter Technology developed blocking SiC diodes specifically designed to withstand harsh space environments during BepiColombo mission to Mercury.

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