Effect of ZrB2 on the ablation behavior of Cf/ZrB2-ZrC-SiC sharp leading edge composites by PIP and RMI

The preparation and ablation resistance of special-shaped components have attracted considerable attention in thermal protection applications. Here we develop Cf/ZrB2-ZrC-SiC sharp leading edge composites by precursor infiltration and pyrolysis combined with reactive melt infiltration, the microstructure and ablation behavior of the composites were investigated. The B2O3 glass generated by the preferential oxidation of ZrB2 during the ablation can not only repair the defects and reduce the surface temperature, but also promote the melting and sintering of ZrO2, thereby enhancing the stability of the oxide layer. Resultantly, the Cf/ZrB2-ZrC-SiC composites with 6.67 wt% ZrB2 remains intact and presents good ablation resistance after ablation for 120 s, whose linear and mass ablation rates are reduced by 63% and 57%, respectively compared with Cf/ZrC-SiC composites. This work provides a promising strategy for constructing a sharp leading edge component for the application of thermal protective materials.