Four point bending tests of a C/SiC material for industrial applications under quasistatic and cyclic loading

The fatigue behavior of a C/SiC material composed of randomly short carbon fiber bundles and a SiC matrix was investigated in four point bending tests. First, the average strengh was measured in quasistatic tests to define the load levels for fatigue investigations. The fatigue tests were performed at different stress levels below the quasistatic strength until fracture or up to a maximum of 10 cyles. With increasing load level the number of fractured specimens increased. How ever, the high residual strength of the specimens after 10 cycles in comparison to the initial state indicated that the damage of the material due to cycling was relatively small. The investigates C/SiC material is thus quite resistant to cyclic fatigue, which represents an advantage under testing, design, and applications.