ZrB2-SiC-Ta4HfC5/Ta4HfC5 Oxidation-Resistant Dual-Layer Coating Fabricated by Spark Plasma Sintering for C/C Composites

In this work, a ZrB2-SiC-Ta4HfC5/Ta4HfC5 oxidation-resistant dual-layer coating was fabricated to improve the oxidation resistance of carbon-carbon (C/C) composites. The coating was prepared by pack cementation combined with the slurry paste method. Spark plasma sintering was used in the procedure. The as-prepared dual-layer coating was approximately 110m, and no distinct interface was observed between the coating and the matrix. The isothermal oxidation test results showed that the dual coating effectively prevented C/C composites from oxidizing. The weight loss of the coated samples was only 3.3 and 9.5% after oxidation at 1773K for 20h and ten thermal shock cycles between 1773K and room temperature in air, respectively. The pores and microcracks were the main reason for the failure of the coating.