Long-time Oxidation Behavior of the Nearly Stoichiometric Polycrystalline SiC Fibers under Air Atmosphere at Different Temperatures

SiC fibers are important reinforcements due to their excellent oxidation and high-temperature resistance. In this work, near-stoichiometric polycrystalline SiC fibers were oxidized in air at 1200 degrees C to 1600 degrees C for up to 100 h. The thickness of the oxide layer reached 1.9 mu m after oxidation at 1400 degrees C for 100 h. Wide cracks appeared on the surface due to residual stress. Activation energy was comparable to that of commercial SiC fibers. The results in this work could provide important reference for such SiC fibers to be applied in the fields of aviation, aerospace, and nuclear power.