Intermediate Temperature Carbon/Carbon Structures

It should be possible to greatly enhance the properties of Carbon-Carbon Composites (CCC) if the materials is designed to be used at temperatures of no more than 1200F. Processing of this new CCC will be aimed at tailoring the material properties to bestable in this intermediate temperature range. The research will be focused at interface coatings, matrix stability and CVD surface coatings with minimal cracking. Interface coatings of carbon will compared to boron nitride based coatings. Matrixprocessing options will include CVD, phenolic resin derived and phenolic resin blends with polymer precursors for silicon carbide. All three matrices will be treated with phosphate solutions for additional matrix oxidation resistance. Low temperature CVDcoatings of Si3N4 will also evaluated for their contribution to oxidation resistance. The cumulative effects of the tailored processing should produce the basis for a new generation of CCC. This research will produce carbon-carbon composites with greaterthermal stability and composites with enhances mechanical properties compared to composites that have been designed for use at temperatures over 2600F. These new materials may provide an alternative to titanium for many aerospace applications.