Boorkarbiid

Boorkarbiid, also known as silicon carbide (SiC), is a compound of silicon and carbon with the chemical formula SiC. It is a hard, dark, crystalline material that occurs in nature as the mineral moissanite. Silicon carbide is a semiconductor material with a wide bandgap, making it suitable for high-power and high-temperature electronic devices. It is also extremely hard and resistant to wear, which makes it useful as an abrasive.

Industrially, silicon carbide is produced by heating silicon dioxide (sand) and carbon (coke) to very high temperatures in an electric furnace. This process, known as the Acheson process, yields a polycrystalline material. Single crystals of silicon carbide can be grown using various methods, including the Lely method.

The properties of silicon carbide depend on its crystal structure, known as polytypes. There are over 250 known polytypes, with the most common being cubic 3C-SiC and hexagonal 4H-SiC and 6H-SiC. These polytypes exhibit different electronic and optical properties.

Silicon carbide finds applications in a wide range of industries. Its hardness makes it an excellent material for grinding wheels, sandpaper, cutting tools, and wear-resistant coatings. In the electronics industry, its semiconductor properties are utilized in power diodes, transistors, and light-emitting diodes (LEDs) capable of operating at high voltages and temperatures. It is also used in refractory materials for furnaces due to its high melting point and resistance to chemical attack.