Carborundum

Carborundum is a trade name for silicon carbide (SiC), a hard, chemically inert ceramic material widely used as an abrasive and, in modern applications, as a semiconductor. It was developed in the late 19th century by Edward G. Acheson, who produced it by heating silica with carbon in an electric furnace. The name carborundum comes from combining carb- with the suffix of corundum, acknowledging its carbide chemistry and resemblance to alumina-based hard materials. Natural silicon carbide occurs in very small amounts as moissanite, but most commercial material is synthetic.

Properties of silicon carbide include a Mohs hardness around 9, a very high melting point near 2700°C, and excellent thermal conductivity. It is unusually abrasion-resistant and chemically inert, yet it is relatively brittle. Silicon carbide exists in several polytypes, which influence its electronic properties and are exploited in semiconductor devices.

Production and forms: SiC is manufactured via the Acheson process and is distributed as powders, grains, and dense ceramic shapes. It is used in bonded or coated abrasive wheels, grinding papers, grinding belts, and lapping compounds for machining and finishing hard materials. In refractories and crucibles, SiC provides high-temperature stability and thermal shock resistance.

Applications in electronics have grown with advances in wide-bandgap technology. SiC serves as a semiconductor material for high-power, high-temperature diodes, transistors, and other devices, benefitting from its ability to operate at higher voltages and temperatures than silicon.

Safety: Processing silicon carbide dust can pose respiratory hazards; appropriate protection and ventilation are recommended.