Carborundum

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Carborundum or SiC is used as an abrasive and in the semiconductor industry for making diodes and moissanite gemstones. Natural moissanite was first found in 1893 in the Canyon Diablo meteorite in Arizona by Dr. Ferdinand Henri Moissan,the material was named after him in 1905.  It  has high thermal conductivity and high electric field breakdown which makes it ideal  to use in high power devices. It used in blue LEds, Schottky diodes.

Who invented Carborundum? Which century was Sic discovered?

Edward Goodrich Acheson invented in the 19th century, 1893. Silicon carbide (SiC), also known as carborundum, is a compound of silicon and carbon with chemical formula SiC.

Where is carborundum found? Is carborundum found in space?

Naturally occurring moissanite is found only in minute quantities in certain types of meteorite and in corundum deposits and kimberlite. It is a commonly found in stardust and in meteorites. Though it is rare on earth it is commonly found in space. SiC grains which were found in the Murchison carbonaceous chondrite meteorite has revealed anomalous isotopic ratios of carbon and silicon. this indicates that the meteorite came from outside of the solar system. The silicon carbide that we find in the world, including the moissanite jewels, is synthetic.

How is Carborundum made?

In 1891, Experiments were being done where clay and crushed coke were heated together through a piece of carbon in an electric furnace, two ingredients fused in the heat, and when carbon was withdrawn, minute crystals stuck to it. The tiny crystals were found to be very sharp and hard. Later tests proved the material was a very good abrasive. About 72,000 horse-power is the total energy used in a single run of a carborundum furnace. This is equal to using an electric arc continuously 24 hrs for 12 years.

Edward Goodrich developed the electric batch furnace method to make SiC and patented it on February 28th,1893. The same method is used even today for the bulk manufacture of SiC. silicon carbide grains are bonded together by sintering to form very hard ceramics. These are used in applications requiring high endurance,such as car brakes, car clutches and bulletproof vests. Lely process is used to manufacture pure SiC. SiC powder is sublimated in argon atmosphere at 2500°C and redeposited into flake-like single crystals,sized up to 2x2 cm², Cubic SiC is grown using the expensive process of chemical vapor deposition Another method used to make pure silicon carbide is the thermal decomposition of poly(methylsilyne), in an inert atmosphere at a low temperature.

Uses of Carborundum. Carborundum applications in Industries.

• SiC is a wide band gap semiconductor which makes it ideal to be used in high voltage, High frequency and High temperature applications
• Industries that depend on carborundum: Automobile industry uses carborundum to make abrasives for grinding wheels
• Electric systems Electronic circuit systems : In high voltage diodes, thyristors
• Astronomy: SiC has a low thermal expansion coefficient, so it is ideal for making mirrors in astronomical telescopes
• Jewelry: SiC crystals are grown by the Lely method and used in jewelry. In Steel industry abrasives are used for grinding
• SiC is used for high performance "ceramic" brake discs
• Carborundum abrasives offers a complete line of high-performance wide belts for all types of hardwoods, softwoods, and manufactured panel products