Influence of copper contamination on ablation damage of C/SiC composites under simulated thermal environment of arc heater

Carbon fiber (CF) reinforced silicon carbide composites (C/SiC) are high-performance lightweight and high-strength materials, rendering promise as hot-structure materials for high-speed aircraft. However, it is critical to evaluate the performance of C/SiC composites in simulated aerodynamic thermal environment due to the impure air of wind tunnel. Herein, we analyze the influence of copper contamination on ablation properties of C/SiC composites in arc heater. Failure mechanism of C/SiC composite is revealed by combining experimental results of static oxidation and theoretical evaluation of ablation process under arc heating. Overall, the presence of copper accelerates oxidation and glassification processes of SiC matrix by forming low-temperature compounds. In addition, the influence of fiber orientation on ablation damage of C/SiC composites is evaluated by combining the distribution of copper-containing phases, airflow distribution, and discrepancies in direction-based thermal conductivity. Results reveal that continuous CF-reinforced micro-zone ceramics resist airflow shear denudation. Furthermore, ablation behavior of needle-punched C/SiC composites under arc heating is discussed in detail.