Improvement of carbon fiber oxidation resistance by thin ceramic coating using silica particles

Abstract

Carbon fiber-reinforced plastics have become indispensable materials in energy saving and new energy technologies, such as automobiles, wind power generators, and hydrogen tanks for fuel cells. However, the lack of oxidation resistance limits the high-temperature applications of carbon fibers. In this study, we developed a coating technology for carbon fibers to improve their oxidative resistance. Carbon fibers with silicon carbide coatings were obtained by the adsorption of silica colloids on carbon fibers using electro adsorption, followed by heating. The resulting coating has small thickness and strong chemical connections. The thermogravimetric analysis confirmed that the oxidation start temperature of the coated carbon fibers was higher than that of carbon fibers. Moreover, the mechanical properties of the coated carbon fibers were maintained. Therefore, the proposed coating technology can broaden the application of carbon fibers as the alternative to some SiC fiber applications. Further, it is applicable for recycling carbon fibers to increase their value in terms of thermal oxidation stability.