Silicon carbide
Description
An extremely hard synthetic Abrasive. Silicon carbide was discovered in 1884 by E.G. Acheson and named Carborundum. He made it made by fusing Coke with Sand in Clay. Silicon carbide is resistant to thermal shock, thermal expansion, and high temperatures. The green to black powder is one of the hardest substances known to man. It is a good conductor of heat and electricity. Silicon carbide is used as an abrasive for polishing glass, granite, and bisque ware. It is also used in the manufacture of porcelain, emery paper, shoe soles, antiskid flooring, kiln shelves, and furnace linings. Moissanite is a jewel quality stone made from silicon carbide that was introduced in 1998 as a simulated diamond. Synthetic moissanite gemstones can be optically similar to diamonds, but can be distinguished because of their thermochromism (change in color with gradual heating), electrical conductivity and birefringence.
Synonyms and Related Terms
moissanite; Carborundum; Unirundum; Carbofrax; Urundum; Siliziumcarbid (Deut.); carbure de silicium; siliciumcarbide (Ned.); kiselkarbid (Sven.); Forever One; Forever Brilliant; Forever Classic; Amora
Risks
- May produce a hazy glaze if residues are left on biscuit.
- Noncombustible.
- Potential carcinogen.
- Contact may cause mechanical irritation.
- Fisher Scientific: MSDS
Physical and Chemical Properties
- Luster = metallic
- Soluble in fused alkalis and molten iron.
- Insoluble in water and ethanol.
- Expansion coef = 5.0
| Composition | SiC |
|---|---|
| CAS | 409-21-2 |
| Mohs Hardness | 9.0 - 9.5 |
| Melting Point | 2700 C (dec) |
| Density | 3.22-3.23 g/ml |
| Molecular Weight | mol. wt. = 40.0855 |
Comparisons
Properties of Common Abrasives
Natural and Simulated Diamonds
Resources and Citations
- G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 713
- The Merck Index, Martha Windholz (ed.), Merck Research Labs, Rahway NJ, 10th edition, 1983 Comment: entry 8636
- Encyclopedia Britannica, http://www.britannica.com Comment: silicon carbide" [Accessed July 26, 2002].
- Wikipedia: http://en.wikipedia.org/wiki/Silicon_carbide (Accessed Sept. 17, 2005)
- Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
- Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976
- Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997
- The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998
- Michael McCann, Artist Beware, Watson-Guptill Publications, New York City, 1979
- R.M.Organ, Design for Scientific Conservation of Antiquities, Smithsonian Institution, Washington DC, 1968