Silicon carbide
Identifiers
CAS number	[409-21-2]
Properties
Molecular formula	SiC
Molar mass	40. CAS registry numbers are unique numerical identifiers for Chemical compounds Polymers biological sequences mixtures and Alloys They are also referred to A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes Molar mass, symbol M, is the Mass of one mole of a substance ( Chemical element or Chemical compound) 097 g/mol
Appearance	black-green odorless powder
Density	3. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different 22 g/cm³, solid
Melting point	2730°C
Solubility in water	insoluble
Hazards
EU classification	not listed
NFPA 704	0 1 0
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Silicon carbide (SiC) is a compound of silicon and carbon bonded together to form ceramics, but it also occurs in nature as the extremely rare mineral moissanite. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. Solubility is the characteristic Physical property referring to the ability of a given substance the Solute, to dissolve in a Solvent. Water is a common Chemical substance that is essential for the survival of all known forms of Life. Council Directive 67/548/EEC of 27 June 1967 on the approximation of laws regulations and administrative provisions relating to the classification packaging and labelling Symbolism The four divisions are typically color-coded with blue indicating level of Health Hazard, red indicating In Chemistry, the standard state of a material is its state at 1 bar (100 Kilopascals exactly Silicon (ˈsɪlɪkən or /ˈsɪlɪkɒn/ silicium is the Chemical element that has the symbol Si and Atomic number 14 Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 A chemical compound is a substance consisting of two or more different elements chemically bonded together in a fixed proportion by Mass. Silicon (ˈsɪlɪkən or /ˈsɪlɪkɒn/ silicium is the Chemical element that has the symbol Si and Atomic number 14 Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 The word ceramic is derived from the Greek word κεραμικός ( keramikos) Moissanite or Silicon carbide (SiC is a rare mineral that can be found in meteorites and in terrestrial samples

Contents 1 Production 2 Discovery 2.1 In nature 3 Properties 4 Uses 4.1 Semiconductor 4.1.1 Lightning arrestors 4.1.2 Circuit elements 4.1.3 High-temperature applications 4.1.4 Ultraviolet detector 4.2 Structural material 4.3 Astronomy 4.4 Abrasive 4.5 Disc brake 4.6 Clutch 4.7 Diesel particulate filter 4.8 Thin filament pyrometry 4.9 Ceramic membrane 4.10 Cutting tools 4.11 Heating element 4.12 Nuclear fuel 4.13 Jewelry 4.14 Steel 4.15 Armour 4.16 Catalyst support 5 In popular culture 6 Patents and trademarks 7 See also 8 Notes and references 9 External links

Production

Due to the rarity of natural moissanite, silicon carbide is typically man-made. Most often it is used as an abrasive where it is often known by the trademark carborundum, and more recently as a semiconductor and diamond simulant of gem quality. An abrasive is a material often a Mineral, that is used to shape or finish a workpiece through rubbing which leads to part of the workpiece being worn away A semiconductor' is a Solid material that has Electrical conductivity in between a conductor and an insulator; it can vary over that This article addresses the many imitations of diamond For a broader discussion of diamonds see Diamond. The simplest manufacturing process is to combine silica sand and carbon in an Acheson graphite electric resistance furnace at a high temperature, between 1600 and 2500 °C. The Chemical compound silicon dioxide, also known as silica or silox (from the Latin " Silex " is an Oxide Sand is a naturally occurring Granular material composed of finely divided rock and Mineral particles Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6

The material formed in the Acheson furnace varies in purity, according to its distance from the graphite resistor heat source. The Mineral graphite, as with Diamond and Fullerene, is one of the Allotropes of carbon. |- align = "center"| |width = "25"| | |- align = "center"| || Potentiometer |- align = "center"| | | |- align = "center"| Resistor| | A heating element converts Electricity into Heat through the process of Joule heating. Colorless, pale yellow and green crystals have the highest purity and are found closest to the resistor. The color changes to blue and black at greater distance from the resistor, and these darker crystals are less pure. Nitrogen and aluminium are common impurities, and they affect the electrical conductivity of SiC.

Purer silicon carbide can be made by the more expensive process of chemical vapor deposition (CVD). Chemical vapor deposition (CVD is a Chemical process used to produce high-purity high-performance solid materials Commercial large single crystal silicon carbide is grown using a physical vapor transport method commonly known as modified Lely method. A single crystal, also called monocrystal, is a Crystalline Solid in which the Crystal lattice of the entire sample is continuous and unbroken Physical vapor deposition (PVD is a variety of vacuum deposition and is a general term used to describe any of a variety of methods to deposit Thin films by the condensation

Purer silicon carbide can also be prepared by the thermal decomposition of a polymer, poly (methylsilyne), under an inert atmosphere at low temperatures. For the biological process see Decomposition. For chemical decomposition in general see Chemical decomposition. "Inert gases" is also used in a narrower sense for Noble gases An inert gas is any Gas that is not reactive with elements Relative to the CVD process, the pyrolysis method is advantageous because the polymer can be formed into various shapes prior to thermalization into the ceramic.

Discovery

The material was manufactured by Edward Goodrich Acheson around 1893, and he not only developed the electric batch furnace by which SiC is still made today but also formed The Carborundum Company to manufacture it in bulk, initially for use as an abrasive. A single crystal, also called monocrystal, is a Crystalline Solid in which the Crystal lattice of the entire sample is continuous and unbroken Minatec (initially called the Mi cro and Na no' tec' hnology Innovation Centre is a European research centre focused on micro-nano technologies Edward Goodrich Acheson ( March 9, 1856 - July 6, 1931) was an American Chemist. A furnace is a device used for Heating The name derives from Latin fornax, Oven. In 1900 the company settled with the Electric Smelting and Aluminum Company when a judges' decision gave "priority broadly" to its founders "for reducing ores and other substances by the incandescent method". The Electric Smelting and Aluminum Company, founded as Cowles Electric Smelting and Aluminum Company, and Cowles Syndicate Company Limited formed in the United ^[1] It is said that Acheson was trying to dissolve carbon in molten corundum (alumina) and discovered the presence of hard, blue-black crystals which he believed to be a compound of carbon and corundum: hence carborundum. Corundum (from Tamil kurundam குருந்தம் or kuruvindam குருவிந்தம் is a Crystalline form of Or, he named the material "carborundum" by analogy to corundum, which is another very hard substance (9 on the Mohs scale). Corundum (from Tamil kurundam குருந்தம் or kuruvindam குருவிந்தம் is a Crystalline form of The Mohs scale of mineral hardness characterizes the scratch resistance of various Minerals through the ability of a harder material to scratch a softer material

In nature

Naturally occurring moissanite is found only in minute quantities in certain types of meteorite and in corundum deposits and kimberlite. Corundum (from Tamil kurundam குருந்தம் or kuruvindam குருவிந்தம் is a Crystalline form of Kimberlite is a type of potassic Volcanic rock best known for sometimes containing Diamonds It is named after the town of Kimberley in South Africa Virtually all of the silicon carbide sold in the world, including moissanite jewels, is synthetic. In Chemistry, chemical synthesis is purposeful execution of Chemical reactions in order to get a product, or several products Natural moissanite was first found in 1893 as a small component of the Canyon Diablo meteorite in Arizona by Dr. Year 1893 ( MDCCCXCIII) was a Common year starting on Sunday (link will display the full calendar of the Gregorian calendar (or a Common The State of Arizona ( is a state located in the southwestern region of the United States. Ferdinand Henri Moissan, after whom the material was named in 1905. Ferdinand Frederick Henri Moissan ( September 28, 1852 &ndash February 20, 1907) was a French Chemist who won the Year 1905 ( MCMV) was a Common year starting on Sunday (link will display full calendar of the Gregorian calendar (or a Common year starting Moissan's discovery of naturally occurring SiC was initially disputed because his sample may have been contaminated by silicon carbide saw blades that were already on the market at that time. A diamond blade may be a circular saw Blade used for cutting hard or Abrasive materials

Analysis of SiC grains found in the Murchison carbonaceous chondrite meteorite has revealed anomalous isotopic ratios of carbon and silicon, indicating an origin from outside the solar system. ^[2] 99% of these SiC grains originate around carbon-rich Asymptotic Giant Branch stars. The asymptotic giant branch is the region of the Hertzsprung-Russell diagram populated by evolving low to medium-mass Stars This is a period of Stellar evolution SiC is commonly found around these stars as deduced from their infrared spectra.

Properties

Silicon carbide exists in at least 70 crystalline forms. Alpha silicon carbide (α-SiC) is the most commonly encountered polymorph; it is formed at temperatures greater than 2000 °C and has a hexagonal crystal structure (similar to Wurtzite). Polymorphism in Materials science is the ability of a solid material to exist in more than one form or Crystal structure In Crystallography, the hexagonal is one of the 7 Crystal system, it contains 7 Point groups. In Mineralogy and Crystallography, a crystal structure is a unique arrangement of Atoms in a Crystal. This article is about the mineral wurtzite For the wurtzite crystal structure see Wurtzite (crystal structure. The beta modification (β-SiC), with a face-centered cubic crystal structure (similar to diamond and zincblende or sphalerite), is formed at temperatures below 2000 °C and is shown in the structure at the top of the page. The cubic crystal system (or isometric) is a Crystal system where the Unit cell is in the shape of a Cube. The diamond cubic Crystal structure is a repeating pattern that atoms may adopt as certain Materials solidify Sphalerite (( Zn, Fe) S) is a Mineral that is the chief Ore of Zinc. Sphalerite (( Zn, Fe) S) is a Mineral that is the chief Ore of Zinc. Until recently, the beta form has had relatively few commercial uses, although there is now increasing interest in its use as a support for heterogeneous catalysts, owing to its higher surface area compared to the alpha form.

Silicon carbide has a specific gravity of 3. 2, and its high sublimation temperature (approximately 2700 °C) makes it useful for bearings and furnace parts. A bearing is a device to permit constrained relative motion between two parts typically rotation or linear movement Silicon carbide does not melt at any known pressure. It is also highly inert chemically. There is currently much interest in its use as a semiconductor material in electronics, where its high thermal conductivity, high electric field breakdown strength and high maximum current density make it more promising than silicon for high-powered devices. A semiconductor' is a Solid material that has Electrical conductivity in between a conductor and an insulator; it can vary over that In Physics, thermal conductivity, k is the property of a material that indicates its ability to conduct Heat. In Physics, the space surrounding an Electric charge or in the presence of a time-varying Magnetic field has a property called an electric field (that can Electric current is the flow (movement of Electric charge. The SI unit of electric current is the Ampere. ^[3] In addition, it has strong coupling to microwave radiation, which together with its high sublimation point, permits practical use in heating and casting metals. Microwaves are electromagnetic waves with Wavelengths ranging from 1 mm to 1 m or frequencies between 0 SiC also has a very low coefficient of thermal expansion and experiences no phase transitions that would cause discontinuities in thermal expansion. When the Temperature of a substance changes the energy that is stored in the Intermolecular bonds between atoms changes In Thermodynamics, phase transition or phase change is the transformation of a thermodynamic system from one phase to another

Pure SiC is colorless. The brown to black color of industrial product results from iron impurities. Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 The rainbow-like lustre of the crystals is caused by a passivation layer of silicon dioxide that forms on the surface. Passivation is the process of making a material "passive" in relation to another material prior to using the materials together The Chemical compound silicon dioxide, also known as silica or silox (from the Latin " Silex " is an Oxide

Uses

Semiconductor

Pure α-SiC is an intrinsic semiconductor with band gaps of 3. An intrinsic semiconductor, also called an undoped semiconductor or i-type semiconductor, is a pure Semiconductor without any significant Dopant In Solid state physics and related applied fields a band gap, also called an energy gap or bandgap, is an energy range in a solid where no electron states 28 eV (4H) and 3. 03 eV (6H) respectively.

Lightning arrestors

The earliest electrical application of SiC was in lightning arresters in electric power systems. A lightning rod (USA or lightning conductor (UK is a single component in a Lightning protection system. These devices must exhibit high resistance until the voltage across them reaches a certain threshold V_T, at which point their resistance must drop to a lower level and maintain this level until the applied voltage drops below V_T. Electrical resistance is a ratio of the degree to which an object opposes an Electric current through it measured in Ohms Its reciprocal quantity is Electrical tension (or voltage after its SI unit, the Volt) is the difference of electrical potential between two points of an electrical

It was recognized early on that SiC had such a voltage-dependent resistance, and so columns of SiC pellets were connected between high-voltage power lines and the earth. Electric power transmission, a process in the delivery of Electricity to consumers is the bulk transfer of electrical power When a lightning strike to the line raises the line voltage sufficiently, the SiC column will conduct, allowing strike current to pass harmlessly to the earth instead of along the power line. Lightning is an atmospheric discharge of Electricity, which typically occurs during Thunderstorms and sometimes during volcanic eruptions or Such SiC columns proved to conduct significantly at normal power-line operating voltages and thus had to be placed in series with a spark gap. If two or more circuit components are connected end to end like a daisy chain it is said they are connected in series. A spark gap consists of an arrangement of two conducting Electrodes separated by a gap usually filled with a Gas such as Air. This spark gap is ionized and rendered conductive when lightning raises the voltage of the power line conductor, thus effectively connecting the SiC column between the power conductor and the earth. An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge Spark gaps used in lightning arrestors are unreliable, either failing to strike an arc when needed or failing to turn off afterwards, in the latter case due to material failure or contamination by dust or salt. Usages of SiC columns was originally intended as a way to eliminate the need for the spark gap in a lightning arrester. Gapped SiC lightning arresters were used as lightning-protection tool and sold under GE and Westinghouse brand names, among others. The gapped SiC arrester has been largely displaced by no-gap varistors that use columns of zinc oxide pellets. A varistor is an electronic component with a significant non- ohmic current - Voltage characteristic Zinc oxide is a Chemical compound with the formula ZnO It is nearly insoluble in water but soluble in Acids and Bases It occurs

Circuit elements

Silicon carbide is used for blue LEDs, ultrafast, high-voltage Schottky diodes, MOSFETs and high temperature thyristors for high-power switching. The Schottky diode (named after German physicist Walter H Schottky; also known as hot carrier diode) is a Semiconductor Diode with The metal–oxide–semiconductor field-effect transistor ( MOSFET, MOS-FET, or MOS FET) is a device used to amplify or switch electronic signals The thyristor is a solid-state Semiconductor device with four layers of alternating N and P-type material A paper by Jayan Baliga^[4] demonstrated the potential of SiC as a power device material.

Currently, problems with the interface of SiC with silicon dioxide has hampered the development of SiC based power MOSFET and IGBTs. The Chemical compound silicon dioxide, also known as silica or silox (from the Latin " Silex " is an Oxide Another problem is that SiC itself breaks down at high electric fields due to the formation of extended stacking faults, but this problem may have been resolved relatively recently. ^[5]

High-temperature applications

Due to its high thermal conductivity, SiC is also used as substrate for other semiconductor materials such as gallium nitride. In Physics, thermal conductivity, k is the property of a material that indicates its ability to conduct Heat. Gallium nitride ( is a very hard material commonly used in bright LEDs since the 1990s Due to its wide band gap, SiC-based parts are capable of operating at high temperature (over 350 °C), which together with good thermal conductivity of SiC makes SiC devices good candidates for elevated temperature applications. In Solid state physics and related applied fields a band gap, also called an energy gap or bandgap, is an energy range in a solid where no electron states In Physics, thermal conductivity, k is the property of a material that indicates its ability to conduct Heat. SiC devices also possess increased tolerance to radiation damage, making SiC a desirable material for defense and aerospace applications. Radiation hardening is a method of designing and testing electronic components and systems to make them resistant to damage or malfunctions caused by high-energy Subatomic particles Gallium nitride is itself also an alternative material in many applications. Although diamond has an even higher band gap, SiC-based devices are easier to manufacture because is is more convenient to grow an insulating layer of silicon dioxide on the surface of a silicon carbide wafer than it is on diamond. In Mineralogy, diamond is the allotrope of carbon where the carbon atoms are arranged in The Chemical compound silicon dioxide, also known as silica or silox (from the Latin " Silex " is an Oxide

Pure SiC is a poor electrical conductor. In Science and engineering, a conductor is a material which contains movable Electric charges. Addition of suitable dopants significantly enhances its conductivity. A dopant, also called doping agent and dope, is an impurity element added to a crystal or semiconductor lattice in low concentrations in order to alter the optical/electrical Typically, such material has a negative temperature coefficient between room temperature and about 900 °C, and positive temperature coefficient at higher temperatures, making it suitable material for high temperature heating elements. Positive Temperature Coefficient ( PTC) refers to materials that experience an increase in Electrical resistance when their temperature is raised A heating element converts Electricity into Heat through the process of Joule heating.

Ultraviolet detector

Silicon carbide is also used as an ultraviolet detector. Ultraviolet ( UV) light is Electromagnetic radiation with a Wavelength shorter than that of Visible light, but longer than X-rays Nikola Tesla, around the turn of the 20th century, performed a variety of experiments with carborundum. There have already been discussions about Tesla's ethnicity on the talk page Electroluminescence of silicon carbide was observed by Captain Henry Joseph Round in 1907 and by O. V. Losev in the Soviet Union in 1923. Electroluminescence (EL is an Optical phenomenon and Electrical phenomenon in which a material emits light in response to an Electric current passed through Captain Henry Joseph Round ( 2 June 1881, Kingswinford, Staffordshire, England &ndash 17 August 1966, Bognor Year 1907 ( MCMVII) was a Common year starting on Tuesday (link will display the full calendar of the Gregorian calendar (or a Common year Oleg Vladimirovich Losev (Олег Владимирович Лосев ( 10 May 1903 - 22 January 1942) was a Scientist and The Union of Soviet Socialist Republics (USSR was a constitutionally Socialist state that existed in Eurasia from 1922 to 1991 Year 1923 ( MCMXXIII) was a Common year starting on Monday (link will display the full calendar of the Gregorian calendar. ^[6]

Structural material

In the 1980s and 1990s, silicon carbide was studied on several research programs for high-temperature gas turbines in the United States, Japan, and Europe. The 1980s was the decade spanning from January 1 1980 to December 31 1989. The 1990s collectively refers to the years between and including 1990 and 1999 The United States of America —commonly referred to as the For a topic outline on this subject see List of basic Japan topics. The components were intended to replace nickel superalloy turbine blades or nozzle vanes. Nickel (ˈnɪkəl is a metallic Chemical element with the symbol Ni and Atomic number 28 A superalloy, or high-performance alloy, is an Alloy that exhibits excellent mechanical strength and creep resistance at high temperatures good surface A turbine is a rotary Engine that extracts Energy from a Fluid flow However, none of these projects resulted in a production quantity, mainly because of its low impact resistance and its low fracture toughness. Toughness, in Materials science and Metallurgy, is the resistance to Fracture of a material when stressed.

Astronomy

Silicon carbide's hardness and rigidity make it a desirable mirror material for astronomical work, although its properties also make manufacturing and designing such mirrors quite difficult. A mirror is an object with a surface that has good Specular reflection; that is it is smooth enough to form an Image. Astronomy (from the Greek words astron (ἄστρον "star" and nomos (νόμος "law" is the scientific study

While rare on Earth, silicon carbide is remarkably common in space. It is a common form of stardust found around carbon-rich stars, and examples of this stardust have been found in pristine condition in primitive (unaltered) meteorites. The silicon carbide found in space and in meteorites is almost exclusively the beta-polymorph.

Silicon carbide may be a major component of the mantles of as-yet hypothetical carbon planets. A carbon planet, also referred to as a diamond planet or carbide planet, is a theoretical type of planet proposed by Marc Kuchner that could form

Abrasive

In the arts, silicon carbide is a popular abrasive in modern lapidary due to the durability and low cost of the material. An abrasive is a material often a Mineral, that is used to shape or finish a workpiece through rubbing which leads to part of the workpiece being worn away A lapidary (the word means "concerned with stones" is an Artisan who practices the craft of working forming and finishing stone, Mineral,

In manufacturing, it is used for its hardness in abrasive machining processes such as grinding, honing, and water-jet cutting. Abrasive Machining is a manufacturing process where material is removed from a workpiece using a multitude of small Abrasive particles Honing is a manufacturing process that produces a precision surface on a workpiece by scrubbing an abrasive stone against it along a controlled path A water jet cutter is a tool capable of slicing into Metal or other materials using a jet of Water at high velocity and pressure or a mixture of water and an

Particles of silicon carbide are laminated to paper to create sandpapers and the grip tape on skateboards. Abrasive Paper is a form of Paper where an Abrasive material has been fixed to its surface

Disc brake

Silicon-infiltrated carbon-carbon composite is used for high performance brake discs as it is able to withstand extreme temperatures. Reinforced Carbon-Carbon ( carbon-carbon or RCC) is a Composite material consisting of Carbon fiber reinforcement in a matrix of Graphite The disc brake or disk brake is a device for slowing or stopping the rotation of a Wheel. The silicon reacts with the graphite in the carbon-carbon composite to become silicon carbide. These discs are used on some sports cars, including the Porsche Carrera GT. The Porsche Carrera GT is a mid-engined Sports car that was manufactured by Porsche in Leipzig Design The Carrera GT is powered

Clutch

Porsche Carrera GT

Diesel particulate filter

Silicon carbide is used in a sintered form for diesel particulate filters. The Porsche Carrera GT is a mid-engined Sports car that was manufactured by Porsche in Leipzig Design The Carrera GT is powered Sintering is a method for making objects from powder, by heating the material (below its Melting point - solid state sintering until its particles adhere

Thin filament pyrometry

Silicon carbide fibers are used to measure gas temperatures in a diagnostic technique called thin filament pyrometry. Thin Filament Pyrometry (TFP is an optical method used to measure temperatures

Ceramic membrane

Silicon carbide is used for producing ceramic membranes for industrial processes, yielding high fluxes due to the sintering process.

Cutting tools

In 1982 at the Oak Ridge National Laboratories, George Wei, Terry Tiegs, and Paul Becher discovered a composite of aluminium oxide and silicon carbide whiskers. Oak Ridge National Laboratory ( ORNL) is a multiprogram science and technology National laboratory managed for the United States Department of Energy by Metal whiskering is a Crystalline metallurgical phenomenon involving the spontaneous growth of tiny filiform hairs from a Metallic surface This material proved to be exceptionally strong. Development of this laboratory-produced composite to a commercial product took only three years. In 1985, the first commercial cutting tools made from this alumina and silicon carbide whisker-reinforced composite were introduced by the Advanced Composite Materials Corporation (ACMC) and Greenleaf Corporation.

Heating element

References to silicon carbide heating elements exist from the early 20th century when they were produced by Acheson's Carborundum Co. A heating element converts Electricity into Heat through the process of Joule heating. in the U. S. and EKL in Berlin. Silicon carbide offered increased operating temperatures compared with metallic heaters, although the operating temperature was limited initially by the water-cooled terminals, which brought the electric current to the silicon carbide hot zone. The terminals were not attached to the hot zone, but were held in place by weights, or springs. Operating temperature and efficiency was later increased by the use of separate low resistance silicon carbide "cold ends", usually of a larger diameter than the hot zone, but still held in place only by mechanical pressure. The development of reaction-bonding techniques led to the introduction of jointed elements. Initially, these featured larger diameter cold ends, but by the 1940s, equal diameter elements were being produced. From the 1960s onwards, one-piece elements were produced, with cold ends created by filling the pore volume with a silicon alloy. Another one-piece technique is to cut a spiral slot in a homogeneous tube where the hot section is desired. Further developments have included the production of multi-leg elements, where two or more legs are joined to a common bridge, and the production of high density, reaction-bonded elements, which provide additional resistance to oxidation and chemical attack. Redox (shorthand for reduction-oxidation reaction describes all Chemical reactions in which atoms have their Oxidation number ( Oxidation state Silicon carbide elements are used today in the melting of non-ferrous metals and glasses, heat treatment of metals, float glass production, production of ceramics and electronics components, etc. Second Album by Rock and roll Singer-songwriter near-legend Graham Parker. Float glass is a sheet of Glass made by floating molten glass on a bed of molten Tin.

Nuclear fuel

Silicon carbide is often used as a layer of the TRISO coating for the nuclear fuel elements of high temperature gas cooled reactors or very high temperature reactors such as the Pebble Bed Reactor. Nuclear fuel is any material that can be consumed to derive Nuclear energy, by analogy to chemical Fuel that is burned to derive energy Nuclear fuel is any material that can be consumed to derive Nuclear energy, by analogy to chemical Fuel that is burned to derive energy The Very High Temperature Reactor is a Generation IV reactor concept that uses a Graphite - moderated Nuclear reactor with a once-through The Very High Temperature Reactor is a Generation IV reactor concept that uses a Graphite - moderated Nuclear reactor with a once-through The pebble bed reactor ( PBR) is a graphite- moderated, gas-cooled Nuclear reactor.

Jewelry

As a Gemstone used in jewelry, silicon carbide is called Moissanite after the jewel's discoverer Dr. A gemstone or gem, also called a precious or semi-precious stone, is a piece of attractive Mineral, which &mdash when cut and polished &mdash Jewellery (also spelled jewelry, see spelling differences) is a personal Ornament, such as a necklace ring or bracelet made from Gemstones Henri Moissan^[7]. Ferdinand Frederick Henri Moissan ( September 28, 1852 &ndash February 20, 1907) was a French Chemist who won the Moissanite is similar to diamond in several important respects: it is transparent and hard (9, although a patent states 8. In Mineralogy, diamond is the allotrope of carbon where the carbon atoms are arranged in 5-9. 0,^[8][9] on the Mohs scale compared to 10 for diamond), with a refractive index between 2. The Mohs scale of mineral hardness characterizes the scratch resistance of various Minerals through the ability of a harder material to scratch a softer material The refractive index (or index of Refraction) of a medium is a measure for how much the speed of light (or other waves such as sound waves is reduced inside the medium 65 and 2. 69 (compared to 2. 42 for diamond). Moissanite is somewhat harder than common cubic zirconia. Cubic zirconia (or CZ) the cubic crystalline form of Zirconium dioxide ( ZrO2) is a Mineral that is widely synthesized Unlike diamond, Moissanite is strongly birefringent. Birefringence, or double refraction, is the decomposition of a ray of Light into two rays (the ordinary ray and the extraordinary ray This quality is desirable in some optical applications, but not in gemstones. For this reason, Moissanite jewels are cut along the optic axis of the crystal to minimize birefringent effects. In Optics, the term optical axis is used to define a direction along which there is some degree of Rotational symmetry. It is lighter (density 3. 22 vs. 3. 56), and much more resistant to heat. This results in a stone of higher lustre, sharper facets and good resilience. Lustre (or luster) is a description of the way light interacts with the surface of a Crystal, rock, or Mineral. Loose moissanite stones may be placed directly into ring moulds; unlike diamond, which burns at 800 °C, moissanite remains undamaged by temperatures up to twice the 900 °C melting point of 18k gold. The KARAT (abbreviation "K" or 'Kt' or "KP" for Karat Plumb is a measure of the Purity of Gold Alloys. Gold (ˈɡoʊld is a Chemical element with the symbol Au (from its Latin name aurum) and Atomic number 79

Moissanite has become popular as a diamond substitute, and may be misidentified as diamond, since its thermal conductivity is much closer to that of diamond than any other diamond substitutes. In Physics, thermal conductivity, k is the property of a material that indicates its ability to conduct Heat. It can be distinguished from diamond by its birefringence and a very slight green, yellow, or gray fluorescence under ultraviolet light. Birefringence, or double refraction, is the decomposition of a ray of Light into two rays (the ordinary ray and the extraordinary ray

Steel

Silicon carbide dissolved in a basic oxygen furnace used for making steel acts as a fuel and provides energy which increases the scrap to hot metal ratio. A basic oxygen furnace, also known as an LD converter, is the place within an integrated steel mill where molten iron from the blast furnace is changed into liquid Steel is an Alloy consisting mostly of Iron, with a Carbon content between 0 Fuel is any material that is burned or altered in order to obtain energy ^[10] It can also be used to raise tap temperatures and adjust the carbon content.

90% silicon carbide is used by the steel industry as a ladle deoxidizer, a source of silicon and carbon in the ladle, an electric furnace slag deoxidizer, and as a synthetic slag additive. In Foundry work a ladle is a container used to transport and pour out molten metals A deoxidizer is a chemical used in a reaction or process to remove Oxygen. Silicon (ˈsɪlɪkən or /ˈsɪlɪkɒn/ silicium is the Chemical element that has the symbol Si and Atomic number 14 Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 In Foundry work a ladle is a container used to transport and pour out molten metals Slag is the By-product of Smelting Ore to purify Metals They can be considered to be a mixture of metal Oxides however ^[11] According to Miller and Company,^[12] it costs less than ferrosilicon and carbon combination, produces cleaner steel due to low level of trace elements, it has a low gas content, it does not lower the temperature of steel, and it has an abundant world wide supply. Ferrosilicon, or ferrosilicium, is a Ferroalloy an alloy of Iron and Silicon with between 15 and 90% silicon Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 In Analytical chemistry, a trace element is an element in a sample that has an average Concentration of less than 100 Parts per million atoms The silicon carbide used as a steel additive or fuel comes as a granular product in either bulk and bags.

50% and 65% silicon carbide are used in the steel industry for processing steel and iron scrap. Steel is an Alloy consisting mostly of Iron, with a Carbon content between 0 Typically supplied as blocks and made from silicon carbide crucible scrap, it helps extend the hot metal supply and raises the tap temperature. A concrete masonry unit (CMU, concrete block, cement block or foundation block is a large rectangular Brick used in Construction ^[13] The blocks are typically made using an automated concrete block making machine, and utilize water and limestone cement as a binder. A concrete masonry unit (CMU, concrete block, cement block or foundation block is a large rectangular Brick used in Construction A concrete masonry unit (CMU, concrete block, cement block or foundation block is a large rectangular Brick used in Construction Water is a common Chemical substance that is essential for the survival of all known forms of Life. Limestone is a Sedimentary rock composed largely of the Mineral Calcite ( Calcium carbonate: CaCO3 In the most general sense of the word a cement is a binder a substance which sets and hardens independently and can bind other materials together

Armour

Like other hard ceramics (namely alumina and boron carbide), silicon carbide is used in composite armour (eg. Boron carbide (chemical formula B4C is an extremely hard Ceramic material used in Tank Armor, Bulletproof vests and numerous Composite armour is a type of Vehicle armour consisting of layers of different material such as Metals Plastics, Ceramics or Air Chobham armour), and in ceramic plates in bulletproof vests. Chobham armour is the name informally given to a Composite armour developed in the 1960s at the British Tank research centre on Chobham Common Ceramic plates (also known as trauma plates) are commonly used as inserts in soft Body armor. A ballistic vest is an item of protective clothing that absorbs the impact from gun-fired Projectiles and shrapnel fragments from explosion Dragon Skin, which is produced by Pinnacle Armor, utilizes disks of silicon carbide. Pinnacle Armor is a United States-based Armor manufacturing company It is light weight, flexible, and rifle round resistant, making it suitable for use on the front lines of battle.

Catalyst support

The natural resistance to oxidation exhibited by silicon carbide, as well as the discovery of new ways to synthesize the higher surface area beta form, has led to significant interest in its use as a heterogeneous catalyst support. The beta cubic form has already been employed for several years as a catalyst support for the oxidation of C4 hydrocarbons, such as n-butane, to maleic anhydride.

In popular culture

• In Edgar Rice Burroughs' Barsoom series, "carborundum" is used as building material for city walls. Edgar Rice Burroughs ( September 1, 1875 – March 19, 1950) was an American author best known for his creation of the jungle hero Barsoom is a fictional version of the planet Mars invented by author Edgar Rice Burroughs for a series of action adventure stories
• In 2001: A Space Odyssey by Arthur C. Clarke (and the related series of books and films) the monoliths (or at least their exteriors) were made of silicon carbide
• In the Discworld novel Monstrous Regiment: Carborundum is the name of the Troll that enlists. For other uses see 2001 A Space Odyssey. 2001 A Space Odyssey ( 1968) is a Science fiction Novel Sir Arthur Charles Clarke, CBE (16 December 1917–19 March 2008 was a British Science fiction Author, Inventor, and Monoliths are advanced Machines built by an unseen extraterrestrial species Discworld is a comedic Fantasy Book series by the British author Terry Pratchett, set on the Discworld, a flat Monstrous Regiment is the 31st novel in Terry Pratchett 's Discworld series
• In the movie Snatch, a pawn shop employee (Sol) determines a diamond is actually Moissanite, much to the dismay of the thief (Bad Boy Lincoln) who stole the ring. Snatch is a 2000 Film by British writer - director Guy Ritchie.
• The name of the material is part of the pun "Illegitimi non carborundum" (Dog Latin for "don't let the bastards grind you down"), which figures into a football fight song of Harvard University among other things. Illegitimi non carborundum is a mock-Latin Aphorism jokingly taken to mean "don't let the bastards grind you down" Dog Latin or mock-Latin refers to the creation of a Phrase or Jargon in imitation of Latin, often by directly translating English
• In the BBC television show Top Gear, host Jeremy Clarkson expresses excitement over the mere mention of silicon carbide used in the brakes and clutch of the Porsche Carrera GT. Top Gear is a BAFTA, multi- NTA and International Emmy Award -winning BBC Television series about motor vehicles mainly Jeremy Charles Robert Clarkson (born 11 April 1960 is an English broadcaster
• Silicon carbide is the material used for the National Design Awards trophy, awarded by the Cooper-Hewitt National Design Museum designed by William Drenttel and Jessica Helfand and manufactured by Norton Electronics. The National Design Awards, founded in 2000, is funded and awarded by Cooper-Hewitt National Design Museum. The Cooper-Hewitt National Design Museum, a subsidiary of the Smithsonian Institution, is the United States ' National museum of design history and contemporary William Drenttel is a Graphic designer Editor and currently a partner in Winterhouse Studios and president emeritus of the American Institute of Graphic Arts Jessica Helfand is an author columnist and lecturer on Graphic design.

Patents and trademarks

Edward Goodrich Acheson (1856–1931) patented the method for making silicon carbide powder on February 28, 1893. Events 202 BC - coronation ceremony of Liu Bang as Emperor Gaozu of Han takes place initiating four centuries of the Han Dynasty 's rule Year 1893 ( MDCCCXCIII) was a Common year starting on Sunday (link will display the full calendar of the Gregorian calendar (or a Common On May 19, 1896, he was also issued a patent for an electrical furnace used to produce silicon carbide. Events 1535 - French explorer Jacques Cartier sets sail on his second voyage to North America with three ships 110 men and Year 1896 ( MDCCCXCVI) was a Leap year starting on Wednesday (link will display the full calendar of the Gregorian Calendar (or a Leap year ^[14] Carborundum is a trademark of Saint-Gobain Abrasives. Saint-Gobain SA ( is a French Multinational corporation, founded in 1665 in Paris and headquartered on the outskirts of Paris at La

See also

• Diamond simulant
• Illegitimi non carborundum, mock-Latin using the trademark Carborundum as if it were a Latin verb gerund. This article addresses the many imitations of diamond For a broader discussion of diamonds see Diamond. Illegitimi non carborundum is a mock-Latin Aphorism jokingly taken to mean "don't let the bastards grind you down" Latin ( lingua Latīna, laˈtiːna is an Italic language, historically spoken in Latium and Ancient Rome. In Linguistics, “gerund” is a term used to refer to various non-finite verb forms in various languages As applied to English,

Notes and references

External links

• Moissanite Buyer's Guide How to buy moissanite jewelry.
• A Brief History of Silicon Carbide Dr J F Kelly, University of London
• Material Safety Data Sheet for Silicon Carbide
• Mindat.org
• discovery of Moissanite by Moissan Moissan studied Meteorites. George Frederick Kunz describes this discovery in USGS annual report.

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