Preparation and comparative study on the mechanical properties and ablation behavior of C/C-ZrxTa1-xC composites

Abstract

Using a self-made ZrC-TaC composite liquid precursor, we introduced Zr_xTa_1-xC solid solution ceramics into a C/C composite matrix via precursor impregnation and pyrolysis (PIP) to fabricate C/C-Zr_xTa_1-xC composites. By optimizing the Zr/Ta ratio, C/C-Zr_xTa_1-xC composites with excellent mechanical and ablative properties were prepared. For the Zr/Ta ratio of 6:1, the composite exhibits a flexural strength of 166.16 ± 13.84 MPa and a flexural modulus of 24.43 ± 2.28 GPa. Under an oxyacetylene flame with a heat flux of 4.18 MW/m², the composite with a Zr/Ta molar ratio of 12:1 exhibited the lowest mass and linear ablation rates of 1.98 mg/s and 5.91 μm/s, respectively. This is because during the ablation process, the Zr-Ta-O composite oxide layer characterized by a solid ZrO₂ framework and liquid phases of Zr₆Ta₂O₁₇ and Ta₂O₅ as pore fillers effectively prevented further oxygen intrusion into the matrix, thereby significantly enhancing ablation performance.