Characterization and Oxidation Behavior of Rayon-Derived Carbon Fibers

Rayon-derived fibers are the central constituent of reinforced carbon/carbon (RCC) composites. Optical, scanning electron, and transmission electron microscopy were used to characterize the as-fabricated fibers and the fibers after oxidation. Oxidation rates were measured with weight loss techniques in air and oxygen. The as-received fibers are similar to 10 mu m in diameter and characterized by grooves or crenulations around the edges. Below 800 A degrees C, in the reaction-controlled region, preferential attack began in the crenulations and appeared to occur down fissures in the fibers.