Erosion resistance of C/C-SiC-ZrB₂ composites exposed to oxyacetylene torch

Carbon/carbon (C/C) composites were modified with SiC-ZrB₂ by reactive melt infiltration (RMI). The erosion resistance of the modified C/C composites, which machined into leading edge to simulate the real working condition, was investigated by exposure to the oxyacetylene torch. The erosion morphology and phase composition were examined by SEM and XRD. After exposure to oxyacetylene torch with a heat flux of 2.38 MW/m² for 60 s, the modified leading edge was slight damaged with linear ablation rate of 0.013 mm/s and mass ablation of 0.0014 g/s, decreased by 70% and 48% compared to pure C/C composites. During ablation, a homogeneous and dense oxide layer was formed on the front of the leading edge, contributing to enhance the ablation resistance of the modified C/C composites. The ablation mechanism of the C/C-SiC-ZrB₂ composites is related to the combined effects of thermochemical ablation by oxidative species and the thermomechanical damage by the shear action of high speed oxyacetylene torch.