Influence of SiC additive on the ablation behavior of C/C composites modified by ZrB2–ZrC particles under oxyacetylene torch

Abstract To determine the effect of SiC additive on the ablation behavior of carbon/carbon composites modified by ZrB 2 –ZrC particles (C/C–Z), C/C–Z and C/C–Z with SiC additive (C/C–Z–SiC) were ablated by oxyacetylene torch for different times up to 240 s. Results showed the improved ablation property of C/C–Z–SiC in comparison with C/C–Z during the initial 120 s but depletion of the improvement with the ablation further proceeding. Meanwhile, the recorded surface temperature of C/C–Z–SiC was lower than that of C/C–Z under the same ablation condition during the initial 160 s after which they tended to be the same. The ablated surface center morphology of C/C–Z–SiC implied that a SiO 2 rich layer was formed beneath the chalked ZrO 2 outer layer within 120 s ablation while the SiO 2 rich layer was almost depleted beyond 240 s. The formation and depletion of SiO 2 rich layer from oxidation of SiC additive dominated the distinct ablation behaviors of C/C–Z–SiC and C/C–Z.