Effect of SiC whiskers on the mechanical and ablation performances of Cu modified C/C composite

To attain a novel ablation-resistant composite for ultra-high temperature structure application, SiC whiskers reinforced C/C-Cu (C/C-SiCW-Cu) composite was fabricated via chemical vapor deposition and infiltration technologies. Microstructure, mechanical and anti-ablation performances of C/C-SiCW-Cu composite were investigated and compared with those of C/C-SiC-Cu composite. The results show C/C-SiCW-Cu composite has significant advantages in compactness, flexural strength and ablation resistance. Because SiC whisker has a high specific surface area, C/C-SiCW-Cu composite has higher capillary force than C/C-SiC-Cu composite for the infiltration of Cu alloy. Meanwhile, the reinforcement of SiC whisker retards the SiC/Cu interfacial debonding during fracture failure process. Schematic models were built to clarify the structural evolution of ablated surface during oxyacetylene ablation tests, and anti-ablation process of C/C-SiCW-Cu composite can be described: forming a compact SiO2 layer, SiC whiskers pinning anti-ablation layer and Cu alloy transpiration cooling effect.