ANALYTICAL CHARACTERIZATION OF COATED CARBON-FIBERS

Carbon fibres must be coated with a barrier layer in their application as reinforcement in metal matrix composites (MMC) to avoid reactions between the matrix and carbon. Materials frequently used are SiC, pyro lytical carbon or these materials in combination. The reactivity betwe en the metallic matrix and the barrier layer depends on the stoichiome try and structure of the barrier material. XPS and AES are suitable me thods for the investigation of the surface and of composition of the l ayer of the coated fibres. Additionally Raman-spectroscopy has been us ed to aid the distinction between the bonding states of carbon in the barrier layer and the fibre. The problems of the analysis of small, fi bre-like materials are discussed.