Rapid heating of silicon carbide fibers under Radio Frequency fields and application in curing preceramic polymer composites

Silicon carbide (SiC) fibers are widely used as a reinforcement in ceramic matrix composites due to their high mechanical strength and superior thermal resistance. Here, we investigate the rapid radio frequency (RF) heating response of two types of SiC fibers (Hi-Nicalon and Sylramic) in 1 MHz to 200 MHz frequency range. We found that Hi-Nicalon fibers exhibit surprisingly rapid RF heating response and that property could be exploited for oven-free and noncontact processing of composites with SiC fibers. We analyze effect of composition, crystallographic structure, and surface impurities on the RF heating response of fibers. The presence of oxygen impurities on the fiber surfaces results in higher heating response in parallel as compared to perpendicular alignment of fibers to the electric field. RF heating response of SiC fibers allows them to act as electromagnetic susceptors in other matrices. We use their RF response to heat preceramic polymers (polycarbosilanes) infiltrated in SiC fibers and cure the...