Microstructure, Mechanical and Ablation Properties of Transpiration Cooling Applied to C/C-SiC Composite for Novel Anti-ablation Material

Taking the advantages of porous ceramic (C/C-SiC composite) and transpiration cooling (Copper alloy), C/C-SiC-Cu composite was fabricated to attain a novel anti-ablation material for high temperature structure application of aerospace systems, via chemical vapor deposition and infiltration technologies. The effects of SiC content on microstructure, thermal conductivity, mechanical and ablation properties of C/C-SiC-Cu composite were investigated. As the SiC content increases from 0 vol% to 25.12 vol%, thermal conductivity, flexural strength and ablation resistance are improved by 84.99%, 78.76% and 53.68%, respectively. Thermal conductivity and thermal diffusivity exhibit proportional linear correlation with SiC content. The high SiC content could shorten the yield stage and increase the breaking strength during the flexural fracture process. When the SiC content is 25.12 vol%, the formation continuous and compact anti-ablation (SiO2) layer is formed by oxidizing and melting fluidity processes during oxyacetylene ablation test, and the protective layer covers the ablation surface and slows down the oxidative ablation, which combines with the transpiration cooling effect of copper alloy to further improve ablation resistance of C/C-SiC-Cu composite.