Tensile and Fatigue Behavior of a Silicon Carbide/Silicon Carbide Composite at 1300°C

Monotonic and fatigue properties of a silicon carbide/silicon carbide composite were studied at 1300°C in tension. All tests were conducted in nitrogen (N2) to eliminate oxidation. Because of the composite architecture and the differences between matrix and fiber properties, the composite failure under both monotonic and cyclic loads took place in stages. In a monotonie test, the composite failure occurred by the creep of bridging fibers, and thus, fibers displayed nonbrittle fracture features. In fatigue tests, although creep was also occurring under cyclic loads, the fracture surface analysis showed that final fracture took place in a brittle manner.