Short-Time Creep Behavior of Carbon, Graphite, and Silica Phenolic Composites at Elevated Temperatures

摘要

Short-time tensile creep behavior of carbon, graphite, and silica phenolics at elevated temperatures was determined for durations up to 40 sec. A plasma arc was used as a heat source, with test temperatures ranging from 1095 to 2760C. The results show appreciable amounts of creep strain, especially for the higher temperature and stress levels. The magnitude of these strains suggests that a complete structural analysis should take account of creep and creep rupture. A surprising result is that the activation energies of creep for carbon, graphite, and silica phenolics are experimentally identical. Observation of identical creep activation energies for composites based on these widely different fibers is contrary to intuitive expectations, since the fiber is usually thought to be dominant in mechanical behavior. (Author)