Silicon carbide sic offers many advantages that have led to its widespread adoption across multiple applications, including 10 times higher breakdown electric field strength and three times greater band gap compared to silicon.
Material for production involves melting carbon and silica at temperatures reaching 2700 degrees Celsius in an electrical resistance furnace before cooling for either black or green forms.
硬度
Silicon carbide (SiC) is one of the hardest materials on Earth, second only to diamond and cubic boron nitride in terms of hardness. This exceptional hardness translates to high wear resistance for components in high pressure environments as well as being an excellent material choice for use in abrasive applications.
As a solid material, aluminum oxide is typically found as an abrasive (in loose form for lapping, mixed with vehicle to form paste or sticks), long-lasting ceramics and aerospace and defense equipment such as satellites and missiles – often due to its ability to withstand harsh environmental conditions including intense heat or radiation exposure.
Though not found naturally, synthetic diamond can be mass produced on an industrial scale through reacting silica with carbon at high temperatures in an electric furnace. Once produced, this dense material features Mohs hardness of 9.5, superior thermal shock resistance with low thermal expansion parameters and can withstand extreme temperatures.
Silicon is resistant to chemical attack and inert under high radiation exposure, making it an excellent material choice for use in astronomical telescopes. Chemical vapor deposition allows it to form mirrors up to 3.5 meters in diameter – as used on space telescopes such as Herschel Space Telescope and Gaia.
Surface treatment methods, including coating and plating, can be used to increase the hardness of SiC. This can be accomplished using thermal spray, cold spray or physical vapor deposition techniques; coatings made up of metals, polymers or ceramics may be applied over the surface of SiC to achieve this. Studies have revealed that when SiC surface is coated with epitaxial graphene it increases by 30% more in hardness.
导热性
Silicon carbide sic boasts an astounding thermal conductivity three times greater than silicon, thanks to its tetrahedral structure and sharing of electron pairs in sp3 hybrid orbitals. As a result, this material can transfer heat quickly across its structure allowing it to operate at higher temperatures, voltages and frequencies than other semiconductor materials.
Thermal conductivity measures the amount of energy transferred through a material over time per unit normal area due to temperature gradients under steady-state conditions, expressed as an SI second rank tensor with heat flow represented by q and temperature gradient represented by T; metal thermal conductivity follows Wiedemann-Franz law while nonmetals may differ based on electrical properties.
Sintered silicon carbide produced using a high purity process has excellent 25degC bend strength which remains consistent up to and beyond its melting point (1410degC). However, as temperature increases this strength diminishes due to exaggerated grain growth of the material.
Silicon carbide is non-metallic material, but can be converted to behave like metal by doping with appropriate impurities. Nitrogen and phosphorus impurities create n-type silicon carbide while aluminum, boron, and gallium dopants can transform it into p-type. Doping allows manufacturers to control its composition stoichiometry as well as tailor its properties specifically for specific applications.
导电性
Silicon carbide (SiC) as a semiconductor material boasts excellent electrical properties, including high breakdown voltages and low turn-on resistance. Silicon and carbon atoms form strong tetrahedral covalent bonds in its crystal lattice that allow dopants such as aluminum, boron and gallium atoms to alter its electrical properties; by doping it with nitrogen or phosphorus impurities doping can create P-type and N-type semiconductor characteristics respectively.
SiC is typically an electrical insulator; however, with impurities present its conductivity can change to meet electronic device applications like power transistors and diodes. Furthermore, SiC’s structural stability and chemical inertness make it an excellent choice for components operating in harsh environments like heat exchangers or flame igniters.
SiC is a popular abrasive in modern lapidary due to its hardness, making it widely utilized for grinding, sandblasting and water-jet cutting applications. Furthermore, due to its high reflectivity and rigidity as well as outstanding stability at higher temperatures it makes an attractive material for use in astronomical mirrors.
Silicon carbide sic stands out among ceramic materials by maintaining its strength at high temperatures without suffering significant deterioration of physical or chemical properties, making it suitable for hard refractories in kilns and furnaces, metalworking tools, abrasives used for metal working applications, thermonuclear fusion reactor applications as it resists neutron transmutations as well as plasma contamination resistance – not to mention possessing one of the highest chemical resistant ratings among fine ceramics which makes it highly effective against corrosion resistant reactor components!
High Voltage Resistance
Silicon carbide’s wide band gap semiconductor property enables it to withstand higher breakdown electric field strengths than standard silicon devices due to its unique atomic structure: Si and C atoms form strong covalent bonds between themselves with electron pairs sharing sp3 hybrid orbitals that contributes to high energy density, lower switching losses, and superior reliability.
Silicon carbide is often chosen for applications that must operate under extreme conditions, such as power electronics and charging systems for electric vehicles. Furthermore, silicon carbide’s ability to withstand higher temperatures contributes to greater efficiency while simultaneously decreasing weight.
Silicon carbide devices offer many advantages over their silicon counterparts in terms of voltage capabilities; specifically they can operate at much higher voltages without risking bridge or melting, making them safer and more reliable options when used for applications such as welding and plasma cutting.
Silicon carbide’s greatest strength lies in its resistance to corrosion and oxidation in harsh chemical environments, including acids, lyes and hydrofluoric acid, commonly found in industrial settings. Furthermore, its exceptional mechanical strength prevents it from shattering when subjected to impact or vibration forces.
Silicon carbide’s unique combination of properties make it an ideal material for high-performance components. Silicon carbide semiconductors feature low switching loss and higher operating temperatures than traditional devices, as well as being energy-efficient due to reduced switching loss and heat shock tolerance – leading to lower fit rates in electric vehicle power electronics and providing more resilient power systems with lower fit rates overall. Furthermore, frequent high-frequency switching improves power conversion efficiency while decreasing electromagnetic interference.
Chemical Inertness
Silicon carbide sic’s chemical inertness allows it to be utilized as a filler material in producing structural ceramics with unparalleled strength and durability. These composite materials have proven themselves in aerospace and automotive applications requiring resistance against extreme temperatures, mechanical stress and chemical corrosion – such as aircraft engines.
Silicon carbide sic is an indispensable material in modern industry due to its hardness and thermal stability. Able to withstand thermal shock and chemical attack, its resistance against oxidation at high temperatures helps preserve semiconductor devices while making this material ideal for wafer handling and inspection applications.
Silicon carbide was first discovered by Edward G. Acheson in 1891 while trying to create artificial diamonds from clay and powdered coke, using an ordinary carbon arc lamp as its heat source. Acheson accidentally discovered this material by tapping heated material against glass, only for it to produce green crystals when tapped on. He therefore named this new compound carborundum after natural corundum mineral forms found within nature – hence its name “silicon carbide.”
Silicon carbide is currently manufactured for use in both abrasive and refractory applications using various production processes. Reaction bonded silicon carbide can be manufactured by infiltrating compacts made up of mixtures of SiC particles with gaseous or liquid silicon; this will cause it to react and bond with carbon, creating additional SiC. Sintering can also produce silicon carbide products.
Sintering silicon carbide involves heating a mix of SiC powder with non-oxide sintering aids to 2000oC in an electric arc furnace, producing a dense ceramic with an extremely low coefficient of thermal expansion and outstanding mechanical characteristics.