silicon carbide


Also found in: Dictionary, Thesaurus, Medical, Acronyms, Wikipedia.

silicon carbide,

chemical compound, SiC, that forms extremely hard, dark, iridescent crystals that are insoluble in water and other common solvents. Widely used as an abrasive, it is marketed under such familiar trade names as Carborundum and Crystolon. It is heat resistant, decomposing when heated to about 2,700°C;; it is used in refractory materials, e.g., rods, tubes, firebrick, and in special parts for nuclear reactors. Very pure silicon carbide is white or colorless; crystals of it are used in semiconductors for high-temperature applications. Silicon carbide fibers, added as reinforcement to plastics or light metals, impart increased strength and stiffness. Silicon carbide is prepared commercially by fusing sand and coke in an electric furnace at temperatures above 2,200°C;; a flux, e.g., sodium chloride, may be added to eliminate impurities. Silicon carbide was discovered (1891) by E. G. Acheson; early studies of it were made by Henri Moissan.
The Columbia Electronic Encyclopedia™ Copyright © 2013, Columbia University Press. Licensed from Columbia University Press. All rights reserved. www.cc.columbia.edu/cu/cup/
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Silicon Carbide

 

(SiC), a compound of silicon and carbon; one of the most important carbides used in industry. In pure form, silicon carbide is a colorless crystal with an adamantine luster; the industrial product is green or blue-black. Silicon carbide exists in two main crystal modifications—the hexagonal (α-SiC) and cubic (β-SiC); the hexagonal modification is a “giant molecule,” constructed in accordance with the principle of a unique structurally directed polymerization of simple molecules. The layers of carbon and silicon atoms in α-SiC are arranged in various ways with respect to one another, thus forming many structural types. The transition from β-SiC to α-SiC occurs at 2100°-2300°C (the reverse transition is usually not observed). Silicon carbide is refractory (melts with decomposition at 2830°C) and is extremely hard (microhardness 33,400 meganew-tons per m2, or 3.34 tonsforce per mm2), being second only to diamond and boron carbide, B4C. It is brittle; its density is 3.2 g/cm3. Silicon carbide is stable in various chemical media even at high temperatures.

Silicon carbide is produced in electric furnaces at 2000°-2200°C from a mixture of quartz sand (51-55 percent) and coke (35-40 percent) with admixture of NaCl (1-5 percent) and sawdust (5-10 percent). Owing to its great hardness, chemical stability, and durability, silicon carbide is widely used as an abrasive (in grinding), as well as for cutting hard materials and sharpening tools. It is also used in the production of various parts of chemical and metallurgical equipment that is operated at high temperatures. Alloyed with various admixtures, it is used in semiconductor technology, particularly at high temperatures. An interesting application of silicon carbide in electrotechnology is in the manufacture of heaters for high-temperature electrical resistance furnaces, lightning rods for power transmission lines, and nonlinear resistors for electrical insulating devices.

G. V. SAMSONOV

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

silicon carbide

[′sil·ə·kən ′kär‚bīd]
(inorganic chemistry)
SiC Water-insoluble, bluish-black crystals, very hard and iridescent; soluble in fused alkalies; sublimes at 2210°C; used as an abrasive and a heat refractory, and in light-emitting diodes to produce green or yellow light.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
- Global silicon carbide industry (smelting and processing, power semiconductors) (market size, key companies, etc.)
Silicon carbide and aluminium powders were heated inside vacuum to 120Adegc for 2 hours to remove any moisture and then mixed in assigned weight ratios, 0.5wt% of magnesium was added to each mix because magnesium serves as a sintering aid while sintering aluminium [17].
As seen from (2) and (3), surface oxidation of silicon carbide in this condition leads to production flow of both as carbon and silicon vacancies from the surface into the bulk of the crystal (maybe mostly of carbon vacancies).
According to the researchers, silicon carbide nanoparticles decrease the amount of calcium hydroxide but increase the amount of stable gel of hydrated calcium silicate (C-S-H).
Project partner Raytheon runs a silicon carbide production plant at Glenrothes in Fife.
The 280 papers delivered during the September 2012 ECSCRM are arranged into ten sessions on bulk growth of silicon carbide, graphen growth, epitaxial growth 4H and 3C, characterization of material and point defects, interface characterization, electrical and structural characterization, MOS processing, and device applications.
Through trial and error testing, it was learnt that the silicon carbide had to be exceptionally fine, such as FFF grade, or finer.
Silicon Carbide is an upcoming alternate material to pure silicon in the field of semiconductors & electronics.
To make a good thing even better, I only have to replace the silicon carbide sheets every four years.
ICSCRM 2009 (the 13th International Conference on Silicon Carbide and Related Materials) was held in October, in Nunberg, Germany.
Most instruments would melt if placed inside the mouth of a volcano, but Alton Horsfall and Nick Wright at the Centre for Extreme Environment Technology at Newcastle University, UK, have been using silicon carbide to create electronic components that can venture where no instruments have ever gone before.
The pumps are manufactured from 316 stainless steel and are fitted with carbon graphite sleeve bearings whose wearing surface has been lined with silicon carbide to a depth of approximately 4 mm.