An AlPO4–SiC–MoSi2/SiC oxidation protective coating on carbon/carbon composites by pulse arc discharge deposition

A new type of oxidation-protective AlPO4–SiC–MoSi2 coating for SiC pre-coated carbon/carbon composites (SiC–C/C) was prepared by a novel pulse arc discharge deposition process. XRD and EDS line scanning analyses show that the phases of the multi-layer coatings are composed of AlPO4, nano-SiC, SiO2 and MoSi2 and the bonding coating between the coating and C/C composites is composed of SiC and Si. In addition, SEM images of the surface and the cross-section of the coating also display the dense microstructure. Oxidation test shows that the as-prepared multi-coating characterized by excellent thermal shock resistance on the surface of C/C composites during exposure to an oxidizing atmosphere at 1873 K can effectively protect the C/C composites from oxidation for 44 h with a weight loss of 1.57%.