Cr ₂ AlC ceramic–modified carbon/quartz fiber composites with enhanced ablation resistance and thermal insulation

Abstract Carbon‐bonded carbon fiber composites (CBCF) are renowned for their lightweight and thermal insulation properties. However, the brittleness and susceptibility to oxidation hinder the widespread application of CBCF. In this work, the carbon‐bonded carbon/quartz hybrid fiber composites (CBCQF) were prepared by pressure filtration and modified by Cr ₂ AlC ceramics. The microstructure, mechanical properties, thermal insulation, and ablation behaviors were investigated. Cr ₂ AlC ceramics notably enhanced the compressive strength of CBCQF in the XY direction and reduced the room‐temperature thermal conductivity in the Z direction. Most importantly, Cr ₂ AlC ceramics significantly improved the ablation resistance of CBCQF. When 40% Cr ₂ AlC ceramics were added, the linear and mass ablation rates of CBCQF were reduced by 38.0% and 93.2%, respectively, compared to the reference sample. Moreover, the study of ablation mechanisms revealed that the improvement in ablation resistance was primarily derived from the formation of the surface protective oxides as well as the reinforcement of oxidation resistance. Overall, this study presents a promising avenue for the application of Cr ₂ AlC ceramics and the modification of fiber composites.