Effect of CrSi2 on the ablation resistance of a ZrSi2-Y2O3/SiC coating prepared by SAPS

To improve the ablation resistance of carbon/carbon (C/C) composites, a proportional amount of ZrSi₂-CrSi₂-Y₂O₃ mixed particles were deposited on the surface of SiC-coated C/C composites by supersonic air plasma spraying (SAPS) to form a ZrSi₂-CrSi₂-Y₂O₃/SiC coating. The microstructure and phase compositions of the coating were studied by SEM, EDS, XRD and its anti-ablation performance was tested by oxyacetylene torch. The experimental results showed that the ZrSi₂-CrSi₂-Y₂O₃ outer coating had a dense microstructure without obvious pores and microcracks, and the thickness reached approximately 150 μm. In the process of being eroded and scoured by the oxyacetylene flame, the coating exhibited excellent anti-ablation property, which was attributed to the mosaic microstructure formed by ZrO₂ and a Si-O-Cr liquid film on the coating surface. After experiencing an ablation time of 80 s, the linear ablation rate and the mass ablation rate of the coating were -1.0 ± 0.03 μm s^-1 and -0.16 ± 0.014 mg s^-1, respectively.