Microstructure and ablation resistance of carbon/carbon composites with a zirconium carbide rich surface layer

Zirconium carbide (ZrC) rich surface layer with a thickness of 80-100 μm was prepared on carbon/carbon (C/C) composites. The ZrC-rich layer consisted of submicron ZrC particles, homogeneously dispersed in the carbon matrix. The mass ablation rate of the composite with the ZrC-rich layer was 69% lower than that of the bare C/C composites. The ZrC-rich layer could seal the surface pores and cracks to restrain the preferential ablation in the defect area and form a continuously melting ZrO2 layer to prevent the carbon from oxidizing during ablation. The strengthened ZrC-rich layer could reduce the mechanical denudation of the composites.