Carbon fibre reinforced silicon carbide

Figure 6.6. Columnar SiC in carbon-fibre-reinforced silicon carbide composites [18]...

Carbon Fibre Reinforced Silicon Carbide Composites (C/SiC, C/C-SiC)... 

CARBON FIBRE REINFORCED SILICON CARBIDE COMPOSITES... 

The most simple methods for preparation of hafnium carbide and its composites are the follows. The powder of HfO was thermally treated with Mg in molar ratio 5 4 under a CH flow ranging from 800 to 950 °C [4]. The effective high temperature coating for carbon fiber reinforced carbon and carbon fibre reinforced silicon carbide was prepared with use of HfC [5]. For this purpose hafnium carbide layers were obtained in a thermally simulated chemical vapor deposition (CVD) reactor on nonporous substrates by reaction of hafnium tetrachloride, methane and addition of hydrogen (Eq. 10.1) ... 

He X-B, Zhang X-M, Zhang CR, Zhou X-G, Zhou A-C, Carbon-fibre-reinforced silicon carbide composites, J Mat Sci Lett, 19(5), 417 19, 2000. 

Nakano K, Kamiya A, Nishino Y, Imura T, Chou T-W, Fabrication and characterisation of three-dimensional carbon fibre reinforced silicon carbide and silicon nitride composites, J Am Ceramic Soc, 78(10), 2811-2814, 1995. 

Xu Y, Cheng L, Zhang L, Yan D, Mechanical properties and microstructural characteristics of carbon fibre reinforced silicon carbide matrix composites by chemical vapour infiltration, Niihara K, Nakano K, Sekino T, Yasuda E eds.. Ceramic Society of Japan, High Temperature Ceramic Matrix Composites III, Proc 3rd Int Conf, Osaka, Sep 6-9 1998, 73-16, Key Eng Mater, Vol 164-165. 

Nakano K, Kamiya A, Ogawa H, Nishino Y, Fabrication and mechanical properties of carbon fibre reinforced silicon carbide composites, J Ceramic Soc Japan, 100(4), 472-475, 1992. 

Graphite fibre reinforced silicon carbide (C/SiC) and silicon carbide fibre reinforced silicon carbide (SiC/SiQ are now the most developed systems. C/SiC is the natural evolution of carbon/carbon composite and can be used up to 1500 C. SiC/SiC is more oxidation resistant but the lack of commercial fibres thermally stable above 1200 greatly limits its application. 

More recently, Stanicioiu, Chinta Hartner (1959) attempted to reinforce the cement with glass fibres, but this was not successful. The most serious study on the reinforcement of dental silicate cement was made by J. Aveston (in Wilson et al., 1972). Silicon carbide whiskers, carbon fibres and alumina powder were introduced into the cement mix. Unfortunately, the glass powder/liquid ratio had to be reduced, and the strength gained by reinforcement was thereby lost. It is clear that dental silicate cement cannot be strengthened by fibre or particulate reinforcement. 

Silicon carbide has attracted considerable interest because of its good mechanical and physical properties and chemical inertness. One of the most important applications of SiC is to produce a matrix reinforced by fibres, forming ceramic-matrix composites. These composite materials exhibit much better fracture toughness than monolithic ceramics. Compared with carbon/carbon composites, fibre-reinforced SiC matrix composites possess superior oxidation resistance and mechanical properties. The Si-C-H-Cl system (e.g. methyltrichlorosilane, CH3SiCl3) has been used for SiC deposition because it is easy to produce stoichiometric SiC deposits. 

The traditional TPS for launcher fairings and re-entry capsules consists of an external ablative insulation, fixed or bonded onto a metallic primary structure. Ablative materials are based on thermosets (phenolic and epoxy resins) or elastomers (ethylene-propylene and silicone rubbers) usually filled and reinforced with cork, cotton, glass, silica, quartz, carbon, silicon carbide, nylon and aramid in the form of powders, fibres, fabrics and felt (Table 2). 

Traditional fibres used as reinforcement in polymer composites are generally either polymers or ceramics the polymer aramids, glass, carbon, boron, aluminium oxide and silicon carbide. Carbon is a high-performance fibre material that is the most commonly used reinforcement in advanced polymer-matrix composites. Glass fibre is readily available and may be fabricated into a glass-reinforced plastic economically using a wide variety of composite-manufacturing techniques. 

Natural fibres such as flax, hemp, silk, jute, sisal, kenaf, cotton, etc are being used to reinforce matrices mainly thermoplastics and thermosets by many researchers. The principal synthetic fibres in commercial use are various types of glass, carbon, or aramid although other fibres, such as boron, silicon carbide, and aluminium oxide, are used in limited quantities. All these fibres can be incorporated into a matrix either in continuous lengths or in discontinuous (short) lengths. Both these fibres have some advantages and disadvantages. 

A very tough 177-204 C versatile curing resin with a continuous service temperature range of -59 to 204 C, and short-term up to 232 C, and designed for RTM. Offers excellent compression properties after impact. Suitable for glass, carbon, aramid, silicon carbide and other fibre reinforcement. 

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