Thermal Protection Behavior of Coated C/C-SiC-TiC Composites Under Simulated Dynamic Combustion Environment at 1700°C

With increasing propulsion ratios in next-generation aeroengines, surface temperatures of turbine blade leading edge have reached 1700°C even after active cooling, making long-term thermal protection systems a critical bottleneck for aeroengine advancements. The carbon/carbon (C/C) composites with excellent high-temperature performance present more promising development prospects. However, their viability for aeroengine application lacks experimental verification. In this work, the SiC/TiC ceramic derived from a single-source precursor was incorporated into C/C composites via precursor infiltration and pyrolysis. A (Zr-Ti)C-SiC-Si/SiC-Si double-layered coating was subsequently prepared on the C/C-SiC-TiC composites through slurry dipping-carbonization and gaseous silicon infiltration. Oxidative ablation behavior of co-prepared sample was evaluated under a 1700°C oxyacetylene flame for 2400 s, revealing a superior long-term ablation resistant property with the lowest linear ablation rate of 0.763 µm/s. A (Zr, Ti)O₂ oxide skeleton and SiO₂ healing phase made a joint contribution as an effective oxygen and thermal barrier during initial ablation. Prolonged ablation time led to SiO₂ depletion and (Zr, Ti)O₂ skeleton erosion by oxyacetylene flame, causing coating failure, whereafter the modified substrate provided the effective protection. Thus, dense ZrTiO₄ phase, TiO₂, and SiO₂ healing phase were formed, which can seal the porous surface of the oxide layer, further enhancing ablation resistance. This work affirms that synergistic matrix and coating modification is an effective strategy to significantly improve the long-term ablation resistance of C/C composites in simulated dynamic aeroengine environment.