Reaction-Bonded Silicon Carbide

Reaction-bonded silicon carbide electrode sleeves... 

Reaction bonded silicon carbide (RBSiC) or self sintered silicon carbide (SSSiC)—see API Standard 682 for SiC application guidelines in mechanical seals... 

Reaction bonded silicon carbides are formed by all of the above techniques. They are then fired in an atmosphere where large amounts of silicon metal is available to react with carbon in the compacted part to form a silicon carbide bond at high temperatures. Residual silicon is left in the pores of these products after firing. 

Infiltration combines a melt with a porous free-standing solid (the preform ). In the main and defining step of the process, the melt flows into open pores of the preform after solidification a new material results. Composites of all classes (polymer, ceramic and metal) are produced by this process, as are compounds such as reaction bonded silicon carbide. The process can also be adapted to make open-pored foams of carbon, ceramic, polymer or metal. 

P. Colombo, V. Sglavo, E. Pippel, and J. Woltersdorf, Joining of Reaction-bonded silicon carbide using a preceramic polymer, J. Mater. Sci. 1998, 33, 2409-2416. 

The present study aims at investigating the Reaction Bonded Silicon Carbide (RBSC) process to produce porous mullite-bonded SiC ceramics. Wu and Claussen (1991) reported a technique to produce mullite ceramics starting from Al, SiC and AI2O3 powder mixtures. However for the purpose of this study it was decided to use only SiC and Al 03 as the precursor powders with SiC as the major component so that after completion of the reaction the microstructure would be SiC bonded with mullite phase, with no residual alumina. This material was then tested for its mechanical properties like Young s modulus. Modulus of Rupture. Properties of Silicate-based SiC refractories have been reported to a certain extent by Reddy and others. Its potential use as a refractory material has been evaluated by measuring its thermal shock resistance. A sample refractory that has been designed in the... 

RBSC (reaction-bonded silicon carbide) is another example of a material formed by a chemical reaction between a solid and a liquid. In this case liquid silicon and solid carbon are the reactants. The sintering temperature (1410°C) is slightly above the melting point of silicon and because the reaction with carbon is strongly exothermic, the rates are high and thermal stresses may develop. If carefully controlled, however, the product has an acceptable density and high strength. 

The slopes of the lines in Figure 13.13, at > 0.75, are also typical for reaction-bonded silicon carbide [24, 28]. These data also indicate that over 75% of the measured axial tensile strain results from cavitation. The volumes generated by cavities are transferred primarily into axial tensile strain [25], which suggests that cavitation is the main creep mechanism of deformation in these ceramics. As the contribution of cavities to strain in SN 281 is dose to zero, creep in this material is fundamentally different from that of other grades of silicon nitride [15, 40, 41, 44]. The suppression of cavitation in SN281 is most likely the reason for its increased creep resistance. 

RBSC. Reaction-bonded Silicon Carbide. See silicon carbide. 

REFEL. Registered tradename (Reactor Fuel Element Laboratory) of the UKAEA Springfields laboratory, for reaction bonded silicon carbide developed there on the basis of P. Popper s original work at British Ceramic R.A. (Power Jets (R D) Ltd, Br. Pat. 866,813, 3/5/61). 

Composites of silicon carbide (SiC) and silicon (Si) are fabricated by the reactive infiltration of molten Si into preforms of SiC particles and carbon. This product is often referred to as reaction bonded silicon carbide (RBSC). SiC materials are used in many applications due to their favorable properties including high hardness, high thermal conductivity, low thermal expansion and high stiffness. This paper demonstrates the manipulation of thermal and mechanical properties through the additions of third phase metals (e.g. A1 and/or Ti) to the infiltration alloy and through the additions of ceramic-forming, reactive materials to the preform. The effects of these additions on microstructural, physical, mechanical, and thermal properties are presented and discussed. 

Chakrabarti, S. Ghosh, and J. Mukerji, Influence of Grain Size, Free Silicon Content and Temperature on the Strength and Toughness of Reaction-Bonded Silicon Carbide, Ceramics International, 20,283-286, (1994). 

Ness, J. N., Page, T. F. (1986). Microstructural evolution in reaction-bonded silicon carbide. Journal of Materials Science, 21,1377-1397. doi 10.1007/BF00553278. 

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