Ta Hf1−B2–SiC multiphase oxidation protective coating for SiC-coated carbon/carbon composites

A TaxHf1−xB2–SiC coating was prepared by in-situ reaction method on SiC coated C/C composites. TaxHf1−xB2 phase is the form of solid solution between TaB2 and HfB2. Isothermal oxidation behavior at 1773 K and ablation behavior of the coated C/C were tested. TaxHf1−xB2–SiC/SiC coating could protect the C/C from oxidation at 1773 K for 1480 h and ablation above 2200 K for 40 s. During oxidation, oxides of Ta and Hf atoms exist as “pinning phases”...