Ablation behavior of 3D PyC-C_f/SiHfBOC Composites under an oxyacetylene torch environment above 2000 °C

A high-pressure assisted precursor impregnation pyrolysis method (PIP) was used to prepare 3D PyC-C_f/SiHfBOC composites. Its anti-ablation properties were tested in an oxygen-acetylene torch ablation environment exceeding 2000 °C. They revealed the ablation behavior and mechanism of SiHfBOC ceramics, carbon fiber, and the PyC interface layer. Under the action of Hf modification, a dense HfO₂-SiO₂ oxide layer was formed in situ on the surface of 3D PyC C_f/SiHfBOC composites, effectively preventing further ablation of the composite's matrix by high-temperature oxidation gases. During the ablation process of an oxyacetylene torch at 2000 °C, it still exhibits excellent anti-ablation properties (linear ablation rate of 1.10 × 10⁻⁴ mm s⁻¹). This work enriches the system of hafnium containing ultra-high temperature ceramic precursors and their composites, which provides beneficial exploration for their application in the ultra-high temperature field.