Effects of hypervelocity impact on ablation behavior of SiC coated C/C composites

SiC coated C/C (SiC-C/C) composites were designed to determine effects of hypervelocity impact on ablation behavior of coated carbon/carbon (C/C) composites. They were impacted at 2 km/s and 3 km/s by steel projectiles driven by solid explosive of pentaerythritol tetranitrate and then ablated by oxyacetylene torch for 100 s at 2500 degrees C. Results showed that ablation areas, the integrity of ablated boundary and ablation rates of all samples increased with the increase of impact velocity. Mass ablation rates of SIC-C/C composites were lower than those of C/C composites under the same test condition. On the contrary, linear ablation rates of SiC-C/C composites were higher than those of C/C composites after the same impact tests. The difference was attributed to the interfaces between SiC coatings and matrix C/C composite. These results demonstrated that morphology of interfaces between coatings and matrix C/C composite was one major factor for the usage of coated C/C composites and could affect the service time of structures with impact damages in high temperature environments. (C) 2016 Elsevier Ltd. All rights reserved.