Abstract: The invention provides a method for producing carbon/carbon composite honeycomb structures which have not only the mechanical properties associated with carbon/carbon materials but high thermal conductivities (>200 w/m-k) as well. A honeycomb structure comprising a low-modulus pitch precursor carbon fiber composite is heated or carbonized to drive off volitiles, densified at low pressure by CVD/CVI to provide a graphitizable carbon matrix, and then heat treated to graphitize both the carbon fiber and the carbon matrix. The resulting honeycomb structure has a high thermal conductivity with an increased fiber modulus and may be used, for example, for making heat transfer devices.

Abstract: This invention describes the infiltration methods used to incorporate ceramic additives in carbon/carbon brake disc preforms. Aqueous vacuum infiltration techniques were employed. Both methods were effective in achieving homogeneous dispersion of ceramic additives throughout brake disc thickness. Heat treatment processes were developed to convert oxide additives to more refractory phases. Both temperature and N.sub.2 overpressure were precisely controlled during conversion. By using the additives, infiltration routes, and heat treatment schedules, brake disc friction material performance properties such as friction coefficient, friction coefficient stability, and brake disc wear rate are improved. The disclosed carbon/carbon brake discs can be used in aerospace, automotive and other friction material applications.