Effect of the Al2O3 additive on the high temperature ablation behavior of the ZrC–ZrO2 coating for SiC-coated carbon/carbon composites

Abstract The Al2O3 additive content in the ZrC–ZrO2 composite coating is adjusted by using the supersonic atmosphere plasma spraying method and the coatings are then tested by the oxyacetylene torch. The influence of the Al2O3 additive content on the anti-ablation property is studied. Results show that the ZrC–ZrO2 coating containing 10 vol% Al2O3 owns the lowest surface porosity and the best ablation resistance property. The ablated area is compact and mainly consists of big grains, which is because the addition of Al2O3 can promote the sintering of liquid ZrO2. The formed Al–Zr–O structure can promote the completeness and stability of the ZrO2 scale, which can inhibit the penetration of oxygen.