High-Temperature and Oxidation Protection Applications

Protection of Carbon-Carbon. A common aerospace material used in aircraft brakes, rockets, and reentry systems is carbon-carbon which comprises a carbon-fiber reinforcement and a carbon matrix. It has the highest specific strength of any material above 1000°C.I l But like all carbon materials, it is susceptible to oxidation and oxidizes rapidly above 500 C. Oxidation protection is provided by silicon carbide which is normally applied by pack cementation or CVD, usually in combination with other materials such as boron to promote self-healing characteristics. 

Oxidaticm protection of carbmi-carbon can be enhanced by the codepositicHi of a hafiiium-carbide and silicon-carbide coating. During oxidatimi, intermediate oxide and silicide compounds are formed vdiich provide an effective oxygen barrier up to 1800 C.1 1 

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