A novel Cr-doped Al2O3-SiC-ZrC composite coating for ablative protection of C/C-ZrC-SiC composites

A novel Cr-doped Al2O3-SiC-ZrC coating systemis proposed to further improve the ablation resistance of C/C-ZrC-SiC composites. Our approach combines low pressure plasma spray method with slurry impregnation of Zr-Cr-Si-C to achieve a specially tailored oxide-carbide structure. Results show that the as-prepared coating was dense and crack-free, which effectively promoted the ablation resistance of C/C-ZrC-SiC with the mass and linear ablation rates decreased by 66% and 76% respectively, involving a highly dense protective structure of A1xCr2-xO3-SiO2-ZrO2 formed during ablation. The compact and continuous multi-oxide scale with “ZrO2-rosette” skeleton intricated with A11.96Cr0.04O3 was evidenced in the ablation center.