Microstructure of pitch-based C/C composites fabricated by HPIC technology

To research the microstructure of C/C composites prepared by high-pressure impregnation-carbonization (HPIC) technology, the 2.5D pitch-based carbon-carbon composites were obtained with 1 K PAN-based HT carbon fibers as reinforcing materials and the modulated coal tar pitch as the matrix precursor. The micro-structures were examined with SEM and the polarized light microscope. Results indicate that, microstructures of the fabricated composites are mainly mosaic structures because of fine holes in the fiber bundle interior, while both mosaic structures and region structures occur among fiber bundles because of big holes. SEM micrographs show that there are some defects in the composites such as holes, cracks, grooves and so on.