Anti-ablation Property of ZrB2/SiC/Ta2O5 Coatings Prepared by Atmosphere Plasma Spraying

Abstract:

To improve the anti-ablation property of carbon/carbon (C/C) composites, the double-layer coatings with SiC/Al₂O₃ as an inner layer and ZrB₂/SiC/Ta₂O₅ as an outer layer were prepared by atmosphere plasma spraying. The phase composition, microstructure and element distribution of the coatings before and after ablation were analyzed using X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy, respectively. There are no cracks on the surface coating and the connection of two coatings and the SiC/Al₂O₃ coating with substrate is well. The distribution of elements Zr, Si and Ta on the coating are similar, which indicates the good homogeneity of coating. Ablation resistance of coated C/C was tested by the oxyacetylene flame at 1800 °C. The mosaic structure formed during the ablation process is conducive to prevent the diffusion of O₂, and the Ta-Si-O glassy layer formed on the surface coating has a protective effect. The coating exhibits a good anti-ablation ability.

Key words:C/C; ablation; mosaic structure; Ta-Si-O glassy layer