MICROSTRUCTURE OF SILICON CARBIDE CARBON COMPOSITES AND RELATIONSHIPSWITH MECHANICAL-PROPERTIES/

Three different 2-D SiC/C composites, analyzed by TEM, have mechanical performances directly controlled by the interfacial structure resulti ng from processing. Localized attachment of the fibers to a brittle ma trix constituent is shown to be responsible for composite weakening by impeding interface debonding and sliding. Moreover, the particulate p hase used in the matrix is found to have a strong influence. There is a consequent sensitivity of composite strength to the particulate prop erties. Finally, it is demonstrated that the hindrance of debonding an d sliding caused by the brittle matrix phase can be suppressed by usin g a C fiber coating,