TENSILE PROPERTIES OF A SICF SIC COMPOSITE

This work examines the mechanical behavior of a 2D woven, 0-90 SiC fib er-reinforced SiC matrix composite. Tensile experiments show that the short-term behavior is largely independent of test temperature below 1 000 degrees C. Microscopic examination reveals that the extent of fibe r pull-out and the integrity of the remaining material are also indepe ndent of temperature in this range. Conversely, at 1200 degrees C, the material retains much of its low-temperature stiffness and proportion al limit, while the strength increases substantially. Micrographs of t hese specimens reveal little individual fiber pull-out and a higher de nsity of matrix microcracks. Room-temperature tensile data show that t he mechanical behavior is rate-dependent; higher strain rates lead to a lower Young's Modulus, higher proportional limit and higher ultimate strength. In-plane shear experiments demonstrate that the unreinforce d matrix strength is approximately 10% of the composite tensile streng th.