Preparation and characterization of sol–gel derived zirconia coated carbon fiber

Zirconia coated carbon fiber for thermal and oxidation protection was prepared through a sol–gel technique. A zirconia sol was synthesized with the zirconium oxychloride, ammonia and polyethylene glycol, each of them acting as the zirconium resource, precipitant and surfactant. The morphology, phase composition and thermal properties of the zirconia coated carbon fiber were evaluated by SEM, EDS, XRD and TG-DTA. The increase of dipping cycles can raise the thickness of the coating, while attaching more ZrO2 crystals on the coating surface. Mass variations of the 3 mol% YSZ and 2 mol% YSZ coated carbon fibers at 800 °C are 20% and 40%, less than the 70% of the uncoated carbon fiber.