Unraveling the oxidation-induced hoop tensile failure mechanism of 2.5D woven C/C–ZrC–SiC composites at 1100-1500°C

The hoop tensile performance of ultra-high-temperature ceramic modified carbon/carbon (C/C) composites is critically important yet notoriously difficult to accurately assess for application in aerospace propulsion systems. This work systematically investigates the hoop tensile failure behavior and mechanism of 2.5D woven C/C–ZrC–SiC composites fabricated by reactive melt infiltration after exposure to oxidative environments at 1100-1500 °C. The composites exhibit the highest hoop tensile strength of 82.76 ± 6.76 MPa after oxidation at 1300 °C, corresponding to a strength retention rate of 98.43%. The formation of a dense in-situ Zr–Si–O oxide layer, along with an optimized fiber/matrix interface, aids in preserving fiber integrity and facilitating effective load transfer. These factors contribute to crack deflection and enhance energy dissipation compared to specimens oxidized at 1100 °C and 1500 °C. Finite element simulation reveals that the macroscopic hoop geometry of the specimen itself results in a stress gradient across the cross-section, with the maximum tensile stress consistently located at the inner surface, which becomes the failure origin. Crucially, a synergistic effect of oxidation-induced intrinsic damage and geometry-driven extrinsic stress concentration accelerates failure. This study advances the engineering application of C/C–ZrC–SiC tubular components in aerospace propulsion systems and provides critical insights for the reliable design of ceramic matrix composites operating in extreme thermal-oxidative environments.