Ablation resistance of (Hf_⅓Zr_⅓Ta_⅓)C solid solution ceramic coating for carbon/carbon composites at 2100 °C

Multicomponent solid solution ceramics have attracted extensive attention for their superior ablation resistance and high-temperature resistance, which are expected to extend the service life of carbon/carbon (C/C) composites under an ablation environment above 2000 °C. Herein, we synthesized (Hf_⅓Zr_⅓Ta_⅓)C solid solution ceramic powders via carbothermal reduction. Then a dense (Hf_⅓Zr_⅓Ta_⅓)C solid solution ceramic coating was deposited on SiC-coated C/C composites by supersonic atmospheric plasma spraying. The coated samples exhibited a low linear ablation rate of −0.61 μm/s after ablation for 120 s, mainly associated with the formation of a compact oxide scale consisting of (Hf, Zr)₆Ta₂O₁₇ and (Hf, Zr)O₂. The refractory (Hf, Zr)O₂ skeleton structure possessed good thermal endurance, and the Ta-rich oxide melt filled the defects of the skeleton.