Preparation and performance of pre-coated carbon layer for carbon/carbon composites

Pre-coated carbon layers on the surface of carbon/carbon composites were prepared firstly by slurry and high-temperature treatment for preparing the anti-oxidation coating with SiC concentration gradient. The micrographs and microstructures of the pre-coated carbon layer were characterized by SEM, Raman and XRD. The effects of different graphite content and carbonization temperature on the microstructure of pre-coated carbon layer were investigated. The bonding strength between the carbon layer and the C/C composites was also measured. The results show that the as-prepared carbon layer is dense and the bend strength reaches 10.5 MPa. The structures of the pre-coated carbon layer are influenced by the graphite content and carbonization temperature, and the pre-coated carbon layers with different structures are obtained.