Oxidation and ablation properties of ZrB₂-SiC based coating for carbon/carbon composites by supersonic plasma spraying

The ZrB₂-SiC based multilayer coating for carbon/carbon composites was prepared by pack cementation, supersonic plasma spraying and chemical vapor deposition. The microstructures of the as-prepared multi-layer coating were characterized by XRD and SEM. The anti-oxidation and ablation properties of coated composites were investigated by isothermal oxidation test and oxyacetylene flame test. The results show that the as-coated samples can provide good oxidation protection at 900, 1100, 1500℃. After oxyacetylene ablation for 60 s, the mass and linear ablation rates are-0.05 mg/s and 0.56 μm/s, respectively. The prepared ZrB₂-SiC based coating can provide good ablation protection for C/C composites, and combined oxidation protection at a wide temperature range.