Effect of Al₂O₃ addition on the ablation behavior of SiC-ZrC coated C/C composites

To improve the ablation performance of the carbon/carbon composites (C/Cs) under ultra-high temperature, SiC-ZrC coatings with different Al₂O₃ content are fabricated on SiC coated C/Cs by supersonic atmosphere plasma spraying. The coating with 10 wt% Al₂O₃ shows a significant improvement on ablation resistance compared with coatings with 0 wt%, 20 wt% and 30 wt% Al₂O₃, which could protect C/Cs for more than 90 s by forming a homogeneous and dense oxide layer. Al ion can be metastable by locating in the center of Si-O rings or Zr-O rings without breaking the bonds. The silica and zirconium dioxide network is integrated.