Effects of Gd2O3 Content on the Infrared Emissivity and Ablation Resistance of HfB2/SiC/TaSi2 Coating at 4400 kW/m2

To improve the infrared emissivity and ablation resistance of HfB2/SiC/TaSi2 coatings for serving in heat flux 4400 kW/m2, with different contents high-emissivity Gd2O3 were prepared using atmospheric plasma spraying. The highest 3–5 μm can reach up to 0.92 at 1273 K when content is 10 vol.%. increase attributed additional electronic transitions induced by oxygen vacancies, which are generated substituting Hf4+ Gd3+. Due high emissivity, surface temperature coating modified vol.% was decreased ~100 K. Meanwhile, mass liner rate confirmed be 4.28 × 10−7 kg/s 2.15 m/s, respectively, 80% 31% compared undoped coating. During ablation, HfB2/SiC/TaSi2/Gd2O3 oxidized HfO2, Gd2Ta2O7, HfSiO4, GdTaO4. A stable Hf–Ta–Gd–Si–O multiphase glass formed on coating, could restrain penetration. However, excessive amount detrimental performance due its consumption SiO2 layer. These findings indicate that addition an appropriate anti-ablation