Microstructure and properties of C/C-ZrC-CuNi composites prepared by a PIP method using inorganic salt as a precursor

To develop active thermal protection for ultra-high temperature ceramics, C/C-ZrC-CuNi composites were fabricated using a PIP method. This study systematically studied the influence of CuNi alloy content on the microstructure, mechanical properties, thermal conductivity, and ablation resistance of the composites. The incorporation of CuNi alloy significantly enhanced the sintering of the ZrC-C matrix, resulting in improved densification of the composites. Furthermore, the presence of CuNi alloy promoted the graphitization of the carbon matrix, thereby enhancing the thermal conductivity. The composites with the highest CuNi alloy content (ZCN4 sample) exhibited the greatest density（2.26 g/cm 3 ） and thermal conductivity（32.3 W/m·k）, along with superior ablation resistance, with mass and line ablation rates of 2.09 mg/s and 2.06 μm/s. This enhanced ablation resistance can be primarily attributed to the sweating cooling effect of the CuNi alloy, which effectively reduces the ablation temperature. Additionally, the formation of Cu 2 O and NiO during ablation acts as sintering aids, facilitating the development of a compact ZrO 2 scale that resists flame erosion. The increased thermal conductivity of the composite further mitigates the temperature rise on the ablation surface.