Stable thermal protection for thousands of seconds in an aerobic environment exceeding 2000°C represents a critical requirement for ultra−high temperature ceramic (UHTC) coatings designed to protect C/C composites. For the ZrC−TaC−SiC coating system applied to C/C composites, two strategies were employed to achieve long−term thermal protection: single−layer coating technique and substrate modification and coating technique. The single coating technique involves directly fabricating a coating system on the C/C composite surface, consisting of a SiC transition layer and a ZrC−TaC−SiC outer coating. Substrate modification and coating technique refers to preparing a ZrC−TaC−SiC coating on the surface of ZrC−modified C/C composites. Results show that the single coating system failed after 720 s of ablation due to the mismatch in thermal expansion coefficients between the outer ZrC−TaC−SiC coating and the SiC transition layer, as well as the formation of pores and cracks caused by the release of gaseous byproducts from SiC oxidation. In contrast, the synergistic protection strategy combining C/C composite substrate modification with a multiphase ZrC−TaC−SiC UHTC coating promoted the formation of a dense oxide film on the coating surface after 1080 s of ablation. The linear ablation rate was on the order of 10−4 mm/s, enabling oxidation and ablation resistance for over 1000 s in a high−temperature airflow environment above 2000°C. This demonstrates outstanding ultra−high−temperature thermal protection performance and lays a technical foundation for practical applications under extreme operating conditions.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |