MECHANICAL AND STRUCTURAL CHARACTERIZATION OF NICALON FIBER-REINFOREED BOROSILICATE GLASS

Work carried out on Nicalon/glass composites as part of a larger progr amme on the structure and properties of ceramic-matrix composites is d escribed and is in contrast to publications by this group on related m aterials in which the interfacial bonding was quite different. As a co nsequence of differences in manufacturing, the interfacial bonding in these more recent materials is substantially improved, as demonstrated by the markedly improved level of shear stiffness (by a factor of 2-3 ) and the higher level of interlaminar shear strength (some 50%-100% i mprovement). There is, however, an accompanying deterioration in the t ensile and flexural strengths. The fracture mode of these Nicalon/boro silicate-glass composites is strongly influenced by the cristobalite c ontent and the properties of the interface, both of which are controll ed to a large extent by the manufacturing parameters.