PRODUCTION OF HIGH-DENSITY CARBON COMPOSITE REINFORCED WITH CARBON FIBER

PURPOSE:To produce high-density C/C composite through a simple process in a low cost by impregnating oriented pitch carbon fibers in pitch, carbonizing and coking, then impregnating the product with a pitch which softens at a specific temperature and is free from the insoluble component in quinoline, and repeating carbonization and coking. CONSTITUTION:Pitch carbon fibers such as a two-dimensionally oriented product such as a carbon fiber cloth laminated material, or a three-dimensionally oriented product such as the cloth laminated material is vertically oriented in the thickness direction, is used as reinforcing fibers and impregnated with a pitch matrix, preferably dry-distilled coal tar at elevated temperature, carbonized by heating it at 500 to 600 deg.C, then graphitized at 2,000 to 3,000 deg.C. The product is impregnated again with a coal tar pitch and/or petroleum pitch softening at 150 to 250 deg.C, free from components insoluble in quinoline and subjected to repetition of carbonization and graphitization operations until the desired density is attained. Thus, a high-density (higher than 1.85g/cm bulk density) carbon fiber-reinforced carbon composite material is obtained.