Effect of ZrB₂ on the ablation behavior of C_f/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 C_f/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 C_f/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 C_f/ZrC-SiC composites. This work provides a promising strategy for constructing a sharp leading edge component for the application of thermal protective materials.