Higher ablative resistance performance of CF-ZrO2/ZrC composites by an in-situ sol-gel method

In the present study, CF-ZrO 2 /ZrC composites with controllable coating thickness were prepared by an in-situ sol-gel method. Through pretreatment , the carbon fibers surface changed from hydrophobic to hydrophilic and the polar groups on the surface significantly increased, which increased the interface affinity and ensured the stabilities of uniform ZrO 2 /ZrC coatings preparation. The coating layer increases the thickness of the composites, prolonged the mass and heat transfer on the composites surface. The dense ZrO 2 /ZrC coating prevents further oxidation of internal C by oxidative gas. As a result, after 4 cycles sol-gel, the mass ablation rate of the composite is decreased from 0.046 to 0.022 mg s −1 , under the butane flame for 120s. And the thermal decomposition temperatures are 10.8%–15% higher than those of the original carbon fiber. Thus, this in-situ sol-gel method is a feasible for preparing carbon fiber self-reinforced composites with uniform coating and designable structure, which can effectively improve the ablative resistance ability and thermal decomposition temperature of composites.