Abstract: The texture and nanostructure of C/C composites infiltrated by improved ICVI procesc was investigated by polarized light microscopy and high spatial resolution transmission electron microscope, respectively. Results show that there are three layers of pyrocarbon with different texture around the fiber. They are smooth laminar, rough laminar and dark laminar pyrocarbon from fiber to exterior, respectively. The interface bonding between the matrix and the fiber as well as that among different texture are well combined. The microcracks generate and propagate in rough laminar pyrocarbon. They do not straight extend through the interface into the lower texture, but propagate by bridged-link through the interface into the lower texture. The preferential orientation of the crystal lattice for the different texture pyrocarbon is quite different in short ranges and long ranges.

Key words: carbon/carbon composites, texture, extinction angle, orientation angle