Grades silicon carbides

Fig. 5. Estimate of the strain gradient in a brass surface abraded on 600-grade silicon carbide paper.

Another silicon carbide multifilament fiber, made via a polymeric precursor by Dow Corning Corp., US A, is called Sylramia According to the manufacturer, this textile grade silicon carbide fiber has a nanocrystalline, stoichiometric... 

Each of the Pyramid foundry sets comes complete with furnace chamber and lid, electric motor, blower-mixer, blower tube, flexible hose, crucible tongs, flask and sand to match size of furnace set that Is ordered, flour silica and a high grade silicon carbide crucible of the proper size. An instruction booklet is included which explains the operation of the furnace, and the method of making molds for metal casting. Each of the above sets is equipped with the supplies shown in the photo, except set No. 1 which Is equipped with 12" assay type tongs. 

Vigorous abrasion of specimens should be avoided, since hydrogen absorption by the specimen may result. It has been found that abrasion of a mild steel surface by 120 grade silicon carbide paper resulted in... 

Abrasive and refractory grade silicon carbide is produced industrially according to the following reaction... 

Abrasive and refractory grade silicon carbide is produced industrially by the car-bothermal reduction of silica, according to the reaction in Eq. (3), from high-purity quartz sand (99.5% Si02) and petroleum coke, in electrically heated resistance furnaces (Acheson furnace) [47]. The reaction is strongly endothermic the heat of formation is 618 kj mol SiC, corresponding to 4.28 kWh kg SiC. 

Seal Face Combinations The dynamic of seal faces is better understood today. Seal-face combinations have come a long way in the past 8-10 years. Stellite is being phased out of the petroleum and petrochemical applications. Better grades of ceramic are available, cost of tungsten has come down, and relapping of tungsten are available near most industrial areas. Silicon carbide is being used in abrasive service. 

Carbon-doped silicon carbide, 22 535 Carbon electrodes, 12 305, 752-758 furnaces using, 12 753 grades of, 72 754 in open-arc furnaces, 72 301 production of, 72 755 properties of, 72 755-756 Carbon elimination, in steelmaking, 23 258 Carbon fiber, 77 214-215 Carbon fiber ceramic-matrix composites, 26 773... 

Ceramic catalytic unit, 10 40 Ceramic composites systems, 5 552-554 Ceramic decoration, use of gold in, 12 693 Ceramic ferrites, 11 59 Ceramic fibers, 24 614, 618 refractory, 13 388 silicon carbide, 13 386 Ceramic-grade fluorspar, 4 579, 580 analysis, 4 577t Ceramic, high temperature... 

Carbothermic Reduction. Silicon carbide is commercially produced by the electrochemical reaction of high grade silica sand (quartz) and carbon in an electric resistance furnace. The carbon is in the form of petroleum coke or anthracite coal. The overall reaction is... 

Porous media are also manufactured from porcelain, glass, silicon carbide, and a number of metals Monel, Inconel, nickel, bronze, Hastelloy C, Stellite L-605, gold, platinum, and many types of stainless steel. Two manufacturers of porous septa are Mott (mottcorp.com) and Pall (pall.com). The air permeabilities of Table 14-23 indicate the relative flow resistances of the various grades to homogeneous fluid but may not be used in designing a disperser for submerged... 

Carrillo-Heian, E.M., Carpenter, R.D., Paulino, G., Gibeling, J.C., Munir, Z. (2001), Dense layered molybdenum disilicide-silicon carbide functionally graded composites formed by field-activated synthesis , J. Am. Ceram. Soc., 84, 962-968. 

Fig. 4.3 Relation between strain-to-failure and minimum creep rate for two commercial grades of siliconized silicon carbide Carborundum KX01 and COORS SCRB 210. In both cases, the strain-to-failure increases as the creep rate decreases.

Results on other composite materials are similar to those obtained by Morrell and Ashbee.56 Creep asymmetry has been demonstrated for two grades of siliconized silicon carbide,35,60,61 SiC whisker-reinforced silicon nitride,53 HIPed silicon nitride,29 and vitreous-bonded aluminum oxide.29 Again, stresses required to achieve the same creep rate were at least a factor of two greater in compression than in tension. In two grades of siliconized silicon carbide,35,58-61 the stress exponent changed from 4 at creep rates below... 

The multifilament fiber (10-20 xm diameter) as commercially produced consists of a mixture of /3-SiC, free carbon and SiOj. The properties of this fiber are summarized in Table 6.5. The properties of Nicalon start to degrade at temperatures above about 600°C because of the thermodynamic instability of composition and microstructure. A ceramic grade of Nicalon, called Hi Nicalon, having low oxygen content is also available Yet another version of a multifilament silicon carbide fiber is Tyranno, produced by Ube Industries, Japan. This is made by pyrolysis of poly (titano carbosilanes) and contains between 1.5 and 4wt% titanium. 

Silicon carbide, SiC (i), and silicon nitride, Si3N4 (2), have been known for some time. Their properties, especially their high thermal and chemical stability, their hardness, and their high strength, have led to useful applications for both of these materials. The conventional methods for the preparation of SiC and SiaN4, the high-temperature reaction of fine-grade sand and coke (with additions of sawdust and NaCl) in an electric furnace (the... 

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