SIC FIBRE BOROSILICATE GLASS COMPOSITE .2. FACTORS CONTROLLING THE MECHANICAL-PROPERTIES/

The variations of ultimate flexural strength, proportional limit and m odulus of Nicalon SiC fibre (similar to 50 vol%)/Pyrex composites have been analysed in terms of fibre hardness and interfacial shear stress and matrix modulus. The ultimate flexural strength increased with an increase in fibre hardness. A relatively high measured interfacial str ess contributed to the high ultimate strength and proportional limit. From these experimental findings, the important parameters controlling the mechanical properties of Nicalon/Pyrex composite were identified, i.e., the degree of fibre damage influencing the ultimate strength, t he interfacial stress influencing the proportional limit, and the matr ix devitrification influencing composite modulus.