THE COMPLEXITY OF THE MATRIX MICROSTRUCTURE IN SIC-FIBER-REINFORCED GLASS-CERAMIC COMPOSITES

In this paper a critical examination of the diagrams of different sili cate systems is presented LAS, MAS YAS, MLAS and YMAS (A. alumina; L. lithia, M: magnesia; S: silica; Y. yttria). These systems have been de veloped to fabricate ceramic matrix composites bused on a glass cerami c matrix, because of their low thermal expansion coefficient and good mechanical properties up to 1000 degrees C. The observations and micro analyses, by transmission electron microscopy, of different batches of MLAS and YMAS confirm the complexity of the systems investigated.