Carbon-fibre-reinforced (YMAS) glass-ceramic matrix composites .1. Preparation, structure and fracture strength

Unidirectional continuous carbon-fibre-reinforced glass-ceramic matrix composites are fabricated for dry sliding applications. The microstructure of the matrix has been characterized by X-ray diffraction and the microtexture and structure of the fibres (pitch-based and PAN-based) have been studied by transmission electronic microscopy. The different fracture behaviours of the composites are described (three-point bend rest and fracture surface observation by scanning electronic microscopy). Due to the thermal expansion mismatch between the fibres and the matrix, a network of microcracks appears in the composites on cooling after hot-pressing. The relationship between the microcrack spacing and the fracture behaviour suggests modifications of the fibre-matrix bond. (C) 1997 Elsevier Science Limited.