Understanding the creep behavior of a 2.5D C-f-SiC composite-I. Morphologyand microstructure of the as-received material

A carbon fiber-reinforced silicon carbide matrix composite (2.5D C-1-SiC co mposite) is characterized from both a morphological and a microstructural p oint of view; as a prerequisite to an investigation of its creep behavior. Using automatic image analysis, various morphological parameters have been characterized: the texture of the woven fibrous preform, the fiber size dis tribution and the volume fraction of macropores. An original study of the p re-existing microcracks has also been conducted to enable a quantitative es timate of the damage in the as-received composite to be made. A microstruct ural investigation down to the nanometric scale, via transmission and high resolution electron microscopies, has revealed the intimate structure of ea ch constituent. Thus, the classical structural elements of the carbon fiber s (i.e. basic structural units and areas of local molecular orientation) ha ve been identified and measured. The texture of the pyrocarbon :interphase has been clearly established especially at the fiber/pyrocarbon and pyrocar bon/matrix interfaces. Finally, the matrix presents the common features of chemically vapor deposited matrices. Published by Elsevier Science S.A.