Effect of Lu₂O₃ addition on the oxidation behavior of SiC-ZrB₂ composite coating at 1500 ℃: Experimental and theoretical study

The effect of Lu₂O₃ on the oxidation behavior of SiC-ZrB₂ composite coating at 1500 ℃ in static air was investigated by oxidation test and first-principles simulations. The Lu₂O₃-SiC-ZrB₂ composite coating protected C/C composites from oxidation at 1500 ℃ for 836 h with a mass gain of only 0.62 mg/cm². The introduction of Lu₂O₃ was beneficial for improving the densification of Lu₂O₃-SiC-ZrB₂ composite coating. The experimental and first-principles simulations results suggest that Zr and Lu atoms tended to diffuse into the SiO₂ network, which further developed the stability of SiO₂ structure, thus leading to a good oxidation resistance of the Lu₂O₃-SiC-ZrB₂ composite coating.