Oxidation-Resistant SiO₂/SiC Coatings on Carbon Fiber Fabrics Prepared by Plasma Electrolysis Spray

Abstract: The applications of carbon fibers are limited above 500 °C by their poor oxidation resistance in oxygen-containing atmosphere. In this study, oxidation-resistant SiO₂/SiC coatings were synthesized on carbon fiber fabric by a novel plasma electrolysis spray process. The microstructure and properties of coatings prepared at different spray distances and different spray times were investigated. The coatings were mainly composed of SiO₂ and SiC with a SiC content varying between about 15 and 95 wt.%. The optimal coating was obtained with a spray time of 30 s and a spray distance of 20 mm; it corresponded to an increase in the fabric burnt-out temperature by 320 °C. Additionally, the mass loss rate was only around 50% at 900 °C, while the bare carbon fiber was burnt out. The kinetics and thermodynamics processes were also investigated in order to understand this novel plasma electrolysis spray process. We believe that this process will find a wide range of applications in the surface modification of fibers. Graphic Abstract: [Figure not available: see fulltext.].