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Silicon carbide, more commonly referred to as Carborundum or SiC, is an extremely hard (9 on Mohs scale) material with excellent thermal properties that is created by heating high-grade silica sand with finely ground carbon in an electric furnace.

Copper has multiple applications in industry and everyday life, such as abrasive sandpaper and grinding wheels, cutting tools, hard ceramic materials, and cutting tools. Furthermore, it can withstand very high temperatures without becoming combustible – an important feature.

Właściwości fizyczne

Silicon carbide’s physical properties include hardness, rigidity and thermal conductivity. It can withstand temperatures up to 1600degC while remaining machineable after going through an intensive sintering and grinding process. Silicon carbide ranks second as an extremely hard material on Earth and can be machined precisely with precision tolerances following costly processes like sintering and grinding.

Moissanite occurs naturally as an extremely rare mineral and is mass-produced as powder and crystal for use in abrasive applications, ceramic plates for bulletproof vests, automotive brakes and clutches, semiconductor devices and gems of jewel quality.

SiC crystallizes in various structures with different stacking arrangements of silicon and carbon atoms, the most prevalent being diamond cubic phase (b-SiC), which is very stable due to similar atomic radii and provides excellent thermal conductivity. SiC is insoluble in water but soluble in molten alkalis and iron. As a crystalline substance it ranges in color from green to bluish black.

Właściwości chemiczne

Silicon Carbide (SiC) is an extremely durable material – chemically inert, thermally stable and used widely across multiple applications ranging from the production of abrasives, thermal management systems and advanced electronics to metal alloy strength enhancement. As a valuable metallurgical additive it reduces refractory losses while improving metal alloy strengths significantly.

SiC can be found naturally as the mineral moissanite in meteorites, but more typically synthesized using the Acheson process, named for its inventor Edward Goodrich Acheson, since late 19th century. This involves heating a mixture of pure silica (silicon dioxide) and finely ground carbon in petroleum coke form to temperatures between 1700-2500 degC in an electric furnace.

SiC exists as multiple polymorphs that differ depending on how its silicon and carbon atoms stack, with alpha silicon carbide (a-SiC), featuring hexagonal crystal structure similar to Wurtzite being most frequently encountered in commercial settings. Beta modifications with face-centered cubic crystal structure such as zinc blende or sphalerite had few applications until recently but are increasingly being utilized as supports for heterogeneous catalysts due to its higher surface area.

Właściwości termiczne

Silicon carbide boasts an exceptional specific heat value and thermal conductivity three times greater than copper, with lower thermal expansion than metals or ceramic materials, making it an excellent material choice for applications involving extreme temperatures or vibrations.

Compound produced from heating silica sand (SiO2) and coke in an electric furnace to very high temperatures, creating yellow-to-green to bluish-black iridescent crystals with yellow to green to green hues and an overall hue of yellow-green-bluish-black depending on temperature settings. Industrial products may contain iron impurities causing brown or black coloring due to Fe2O3 presence.

Pure silicon carbide behaves as an electrical insulator, but its wide band-gap semiconductor properties make it suitable for power electronic applications. Doping can include nitrogen or phosphorus to achieve metallic conductivity while beryllium, boron, aluminium or gallium can be added for increased operating voltage – ideal for applications like electric vehicle inverters.

Właściwości mechaniczne

Silicon carbide has the ability to withstand extremely high temperatures, making it an excellent material for use in refractory linings and ceramic materials. Furthermore, silicon carbide can also be made into abrasive materials such as sandpaper, cutting tools, and grinding wheels for use in high pressure/high temperature applications such as automobile parts and rocket nozzles.

Molten salt has an Mohs hardness rating of 9, making it a tough material. Furthermore, its chemical inertness means it remains unchanged by acids, alkalis, or other solutions such as acids. Furthermore, temperatures up to 2700 degC will not compromise or alter its properties in any way.

Silicon carbide powder can be combined with non-oxide binder to form a paste that can then be compacted and shaped using cold isostatic pressing or extrusion. Clay is often the chosen choice as it prevents SiO2 evaporation at neck regions between particles while encouraging densification – making this technique both economical and efficient in producing dense silicon carbide products.