MICROSTRUCTURAL CONTROL OF PITCH MATRIX CARBON-CARBON COMPOSITE BY IODINE TREATMENT

Matrix microstructure of a pitch-based carbon-carbon composite was con trolled by an iodine treatment. Coal-tar pitch having the softening po int of 101 degrees C was used as a matrix precursor. The iodine treatm ent was carried out on a pitch-impregnated specimen at 90 degrees C fo r 3-20 h. The specimen was carbonized at 800 degrees C and graphitized at 2000-3000 degrees C. The carbon yield increased from 73% to 93% by the iodine treatment. Microstructures of carbonized specimens changed from a flow type texture to a mosaic type one by the iodine treatment . The microstructural development to graphitic structure was suppresse d by the iodine treatment.