Effect of ablative angles on the ablation behaviors of ZrB₂-SiC modified carbon/carbon composites

To analyze the effect of different ablation angles on the ablative property of carbon/carbon(C/C) composites modified by ZrB₂-SiC, C/C-ZrB₂-SiC composites (ZS) were prepared via precursor infiltration and pyrolysis (PIP). The prepared composites (ZS) were then ablated by oxyacetylene flame at 90° and 0° angles (ZS-90° and ZS-0°), respectively. The results show that, at ZS-0° angle, the ablation resistance was worse due to the existence of turbulent flame. The temperature in the inner cone and the gas flow velocity at ZS-0° were higher than those at ZS-90°. At ZS-90°, the damage of the composites was dominated by the thermo-chemical ablation. The ablation mechanism at ZS-0° was mainly the mechanical denudation with the thermo-chemical ablation as supplement. The dissimilar ablation angles of the C/C-ZrB₂-SiC composites under the oxyacetylene flame resulted in the distinct ablation resistance on the surfaces, hence different ablation mechanisms.