Strengths of Ceramic Fibers at Elevated Temperatures

Tensile strengths were measured and Young's moduli were estimated for two SiC‐based and three oxide ceramic fibers for temperatures from 25° to 1400°C. The SiC‐based fibers were stronger but less stiff than the oxide fibers at room temperature and retained more of both strength and stiffness to high temperatures. High‐temperature strengths of the SiC‐based fibers were limited by internal void formation and oxidation; those of the oxide fibers were limited by softening of an intergranular glassy phase.