TEMPERATURE DEPENDENCE ON THE STRENGTH AND STRESS RUPTURE BEHAVIOR OF A CARBON-FIBER REINFORCED SILICON CARBIDE MATRIX (C/SiC) COMPOSITE

摘要

Tensile strengths and stress rupture lives of carbon- fiber reinforced silicon carbide (C/SiC) specimens were measured at 800℃ and are compared to previously reported 1200℃ data. All tests were conducted in an environmental chamber containing 1000 ppm of oxygen in argon. The average 800℃ tensile strength of 610 MPa is 10% greater than at 1200℃. Average stress rupture lives at 800 ℃ were 2.5 times longer than those obtained at 1200℃. The difference in the 800 and 1200℃ lives is related to the oxidation rate of the reinforcing carbon fibers, which is the primary damage mode of C/SiC composites in oxygen-containing environments.