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

In this work, a ZrB 2 -SiC-Ta 4 HfC 5 /Ta 4 HfC 5 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 110 μm, 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 1773 K for 20 h and ten thermal shock cycles between 1773 K and room temperature in air, respectively. The pores and microcracks were the main reason for the failure of the coating.