Design and characterization of zirconium-based multilayer coating for carbon/carbon composites against oxyacetylene ablation

Aiming to ameliorate the rapid oxidization and deterioration of carbon/carbon (C/C) composites in extreme environments, a novel multilayer coating containing ZrO2-Y2O3, ZrC-ZrO2 and ZrC-SiC layers from surface to inside was prepared on SiC-coated C/C composites via plasma spraying. Its scale evolution was studied under exposure to an oxyacetylene torch above 2000 ℃. Only the multilayer coating survived after ablation for 90 s × 2 and maintained an integrated appearance, whereas the other monolayered coatings were failure prematurely. The monotonically decreased thermal expansion and multiple roles gathering thermal shield, crack termination and oxidation retardation accounted for its preferable ablation resistance. •A novel zirconium-based multilayer coating was fabricated on SiC-coated C/C composites by plasma spraying.•It owned preferable ablation property than monolayered coatings under exposure to oxyacetylene torch.•Monotonically reduced thermal expansion lessened the detrimental effect of cracks.•The scale with multiple characters including thermal shield, gradient and oxidation retardation accounted for its high protection.