Investigations of Micro- and Nano-structures of C/C Composite Fabricated by CVI

摘要

The morphology, microstructure and graphitization degree of C/C composites fabricated by chemical vapor infiltration were studied by scanning electron microscope (SEM), high-resolution transmission electron microscope (HRTEM). The pyrolytic carbon matrix consists of flakes with the thickness from several tens to several hundreds nanometer. These flakes are oriented parallel to the fiber surface. They are of rough laminar structures and are easily folded so as to form a lot of micro-cracks. A disorder zone with the thickness of about 15nm was also identified between the carbon fiber and pyrolytic carbon. Election diffraction analyses and HRTEM observations also revealed that the graphitization degree of pyrolytic carbon near the interface was lower than those in the outer of the pyrolytic carbon.