Analytical characterization of coated carbon fibres

Summary 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, pyrolytical carbon or these materials in combination. The reactivity between the metallic matrix and the barrier layer depends on the stoichiometry and structure of the barrier material. XPS and AES are suitable methods for the investigation of the surface and of composition of the layer of the coated fibres. Additionally Raman-spectroscopy has been used to aid the distinction between the bonding states of carbon in the barrier layer and the fibre. The problems of the analysis of small, fibre-like materials are discussed.