Ablation resistance and mechanical properties of C/C-HfC-SiC composites with a bulletproof-like layer

Two structural designs are based on the arapaima fish scale structure to enhance the performance of composites. A double-layer SiC/PyC coating was deposited to modify C/C-HfC-SiC composites by chemical vapor deposition. The introduction of PyC coating reduced the porosity and roughness of composites. Ar-O2-Al2O3 plasma ablation system was used to assess the composites. The composites with arapaima fish scale structure showed good flexural and ultra-temperature particle erosion resistance. The samples with the introduction of PyC layer showed higher flexural strength of 220 MPa, which is 40.13 % higher than that of without. After ablation 40 s, the linear ablation rates decreased from 5.95 mu m/s to-4.6 mu m/s. This study provides new ideas to develop C/C composites with improved ablation-resistant and mechanical properties.