The oxidation resistance of Hf‐Ta‐Si‐B‐O glass film reinforced ZrB ₂ –SiC coating in wide temperature range environments

Abstract To reduce the oxidation loss of ZrB 2 –SiC ceramic coatings in the early stage of oxidation and minimize coating oxidation defects, a Hf‐Ta‐Si‐B‐O outer layer glass film was coated on the surface of ZrB 2 –SiC coatings by the slurry brushing method, and oxidation tests were conducted. The experimental results showed that the coating with the Hf‐Ta‐Si‐B‐O outer layer glass film formed a continuous protective layer in the early stage of oxidation, and the final weight gain in the wide temperature range from 600 to 1600°C was suppressed to 4.60% of that of the pure ZrB 2 –SiC coating. The Hf‐Ta‐Si‐B‐O/ZrB 2 –SiC coating with 10 wt.% Ta 2 O 5 addition had the best oxidation protection effect, with an average oxygen permeation rate of only 0.34%, a final carbon loss rate of only 0.12 × 10 −6 g·cm −2 ·s −1 , and a final protection efficiency of 99.97% after oxidation at 1700°C for 100 min. The Hf‐Ta‐Si‐B‐O/ZrB 2 –SiC coating showed a dual protection mode of “low‐temperature dense barrier + high‐temperature dynamic healing” during cyclic oxidation in the wide temperature range from 600 to 1700°C.