Application of Carbides

Coated abrasives include abrasive paper and cloth in sheet or band form. These are produced by strewing the SiC grains onto a substrate coated with glue or bonding resin, and then covering with a second layer of bonding agent [544]. 

The addition of SiC during the melting of cast iron aids carburization and siliconization, and improves the quality of the cast iron as a result of its seeding action [549]. In the production of steel in an arc furnace, SiC acts as deoxidant and helps in slag melting. 

The resistance of ceramically bonded and recrystallized SiC to thermal shock, oxidation and corrosion is utilized in its use as a refractory construction material, for example, in the linings and skid rails for furnaces and hot cyclones, and as a kiln furniture, especially in saggars [164,552-556]. The good electrical conductivity of the material at high temperatures, coupled with its outstanding oxidation resistance, led to its early use in the electric heating industry [557-559], which markets its products 

Silicon carbide is an outstanding material for the construction of electronic equipment. Blue light-emitting diodes having an improved 470 nm peak wavelength are being produced and marketed as the first commercial SiC semiconductor device. 

The continual development of the deposition of SiC thin films and of large-diameter single crystal SiC wavers, and the associated technologies of doping, etching and electrical contacts, have culminated in a host of new solid-state devices that includes field effect transistors (FETs) capable of operation up to 650 °C [562]. 

---

ISO Recommendation R-513, Application of Carbides for Machining by Chip Eemoval, 1st ed.. International Organisation for Standardization, Nov. 

Wang, H.L. and Gao, Q.M. Synthesis, characterization and energy-related applications of carbide-derived carbons obtained by the chlorination of boron carbide. Carbon Al, 820-828, 2009. 

Based on those observations, we can conclude that the oxidation temperature and process of nonstoichiometric ZrC, especially that with ordered carbon vacancies, are strongly dependent on the concentration and state of carbon vacancies. The ordered vacancies provide the additional fast tracks for the oxygen diffusion, inducing the fast oxidation of non-stoichiometric ZrC. The ordered carbon vacancies are not conducive to the application of carbides at high temperature and under aerobic conditions. However, the fast oxidation of ordered ZrC provides a new route to fabricate the metastable tetragonal zirconia nano-powders. 

ANSI/IEEE-C62.2/1994 Guide for application of gapped silicon carbide surge arrester for a.c. systems ... 

An appreciation of statistical results can be gained from a study conducted to support the first application of computer control for an ethylene oxide production unit at Union Carbide Corporation in 1958. For the above purpose, twenty years of production experience with many units was correlated by excellent statisticians who had no regard for kinetics or chemistry. In spite of this, they did excellent, although entirely empirical work. One statement they made was ... [ethane has a significant effect on ethylene oxide production.] This was rejected by most technical people because it did not appear to make any sense ethane did not react, did not chemisorb, and went through the reactor unchanged. 

Carbide-based cermets have particles of carbides of tungsten, chromium, and titanium. Tungsten carbide in a cobalt matrix is used in machine parts requiring very high hardness such as wire-drawing dies, valves, etc. Chromium carbide in a cobalt matrix has high corrosion and abrasion resistance it also has a coefficient of thermal expansion close to that of steel, so is well-suited for use in valves. Titanium carbide in either a nickel or a cobalt matrix is often used in high-temperature applications such as turbine parts. Cermets are also used as nuclear reactor fuel elements and control rods. Fuel elements can be uranium oxide particles in stainless steel ceramic, whereas boron carbide in stainless steel is used for control rods. 

As with borides (p. 145) and carbides (p. 297) the formulae of metal silicides cannot be rationalized by the application of simple valency rules, and... 

Many CVD reactions are being investigated for the deposition of carbides and nitrides, particularly for titanium nitride for semiconductor applications, such as diffusion barrier. The following is a summary of the metallo-organic precursors and deposition condition presently used in development or production of these materials. 

Wear, Erosion, and Corrosion Applications of Refractory Carbides and Nitrides... 

The main applications of coated cemented carbides are tips and blanks, indexable inserts, milling tools, turning, and boring tools and circular saws. 

CVD silicon carbide fibers are a recent development with prom-ising potential which may take over some of the applications of CVD boron fibers or other refractory fibers, providing that the production cost can be reduced. 

The application of ly transition metal carbides as effective substitutes for the more expensive noble metals in a variety of reactions has hem demonstrated in several studies [ 1 -2]. Conventional pr aration route via high temperature (>1200K) oxide carburization using methane is, however, poorly understood. This study deals with the synthesis of supported tungsten carbide nanoparticles via the relatively low-tempoatine propane carburization of the precursor metal sulphide, hi order to optimize the carbide catalyst propertira at the molecular level, we have undertaken a detailed examination of hotii solid-state carburization conditions and gas phase kinetics so as to understand the connectivity between plmse kinetic parametera and catalytically-important intrinsic attributes of the nanoparticle catalyst system. 

The conventional production method for SiC - the reaction of coke and sand (Acheson process) -does not involve soluble or fusible intermediates. For many applications of silicon carbide this fact is not necessarily a disadvantage, but for the preparation of ceramic composites such intermediates are required. 

Jefferson s studies of the pyroxenoids has added greatly to our application of the way in which, through the intermediary of planar - or planar and Kinke - faults one structure is converted into another (45). And Audier, Jones and Bowen (46) have revealed how unit cell strips of Fe C may be accommodated as extended defects in the Fe C structure. Both these carbidic phases can be readily identified by HREM at the interface of iron catalysts used for the disproportionation of CO (to yield C j+CC ). 

Apart from the reactions described above for the formation of thin films of metals and compounds by the use of a solid source of the material, a very important industrial application of vapour phase transport involves the preparation of gas mixtures at room temperature which are then submitted to thermal decomposition in a high temperature furnace to produce a thin film at this temperature. Many of the molecular species and reactions which were considered earlier are used in this procedure, and so the conclusions which were drawn regarding choice and optimal performance apply again. For example, instead of using a solid source to prepare refractory compounds, as in the case of silicon carbide discussed above, a similar reaction has been used to prepare titanium boride coatings on silicon carbide and hafnium diboride coatings on carbon by means of a gaseous input to the deposition furnace (Choy and Derby, 1993) (Shinavski and Diefendorf, 1993). 

PolyCy-benzyl L-glutamate) (PBLG), 15 109 Poly(y-ketosulfide)s, optically active, 23 711 Poly(P-alanine), 1 292 Poly-P-hydroxybutyrate (PHB), 12 482 Polybetaines, 20 479-482 applications of, 20 482 preparation of, 20 480-481 solution properties of, 20 481-482 synthesis of, 20 479-481 Polyborates, 4 256-258 Polyborosiloxanes, in silicon carbide manufacture and processing, 22 533 Polybrominated diphenyl ethers (PBDEs), 13 142-143 20 56... 

Sodium calcium pentaborate pentahydrate, 4 242t, 278-279 Sodium carbide, 22 765 Sodium carbonate, 20 631, 22 765, 787-797, 23 669, 3 416. See also Soda ash applications of, 22 794-795 from brine, 5 799-800 carbon dioxide recovery from natural gas using, 4 811... 

Water system design, 20 757-760 applications of, 20 764 Water systems, high purity, 77 807-808 Water-to-carbide acetylene generators, 7 207... 

Main uses of the metal. Applications of Ta in medicine (in prosthetic implants) are also well known because of its lack of toxicity and excellent compatibility with tissue. It is used for producing capacitors. Tantalum carbide is used in cutting tools. 

Application of carbo-thermal reduction. This is a synthesis process for the preparation of powders of carbides, nitrides and borides. Carbon may be graphite, coke, pyrolysed organic polymers. A reference process may be the Acheson process for the production of SiC ... 

A number of applications of power ultrasound are to be found in heavy industry both in metalworking and processing [17]. The machining of modem materials requires tools that can deal with unusual properties, complex shapes of work-pieces, and accuracy in working. Basic ultrasonic machining processes become of importance when dealing with carbides, stainless steels, ceramics and glass. Four main types of application are of industrial relevance ... 

---