Microstructure of C/C composites prepared by chemical vapor infiltration method with vaporized kerosene as a precursor

The microstructures of two types of C/C composites prepared from different carbon felts by a rapid densification method, thermal gradient chemical vapor infiltration with vaporized kerosene as a precursor, at 1080-1120 °C for 6 h were characterized by polarized light microscopy (PLM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman micro-spectrometry techniques. The experimental results show that the fibers in the two composites are both surrounded by ring-shaped pyrocarbons with rough laminar texture, but the thickness, the surface morphology of the pyrocarbons and the graphitizability of the composites depend much on the configurations of carbon felts. The C/C composite fabricated from a higher porosity carbon felt possesses larger thickness and rougher surface of pyrocarbon, and has a lower graphitizability after heat treatment at 2300 °C for 2 h.