Nose-shaped ZrC-C composites with gradient pore structure (ZrC-C_GS) were successfully prepared by isothermal chemical vapor infiltration using ZrC skeleton as preform. Pyrolytic carbon with medium texture was deposited around ZrC skeleton. From the top to back, the porosity of the ZrC-C_GS composites increased gradually from 0% to 62.9%. Compared with the ZrC-C composites with dense structure (ZrC-C_DS), the mass ablation rate of the ZrC-C_GS composites decreased by 15.3% and the heat resistance capacity increased by 45.6%, and their coefficients of thermal expansion decreased obviously in the temperature range of 200–1500 °C. The simulation results showed that the residual thermal stress and back temperature of the ZrC-C_GS composites are lower than those of the ZrC-C_DS composites. This work provides an effective strategy for designing and preparing ultra-high temperature composites having both ablation and heat insulation performances by controlling the pore structure and distribution.

以ZrC骨架为预制件，通过等温化学气相渗透成功制备了具有梯度孔结构的鼻形ZrC-C复合材料（ZrC-C _GS）。中等质地的热解碳沉积在 ZrC 骨架周围。从上到下，ZrC-C _GS复合材料的孔隙率从 0% 逐渐增加到 62.9%。与致密结构的ZrC-C复合材料（ZrC-C _DS）相比，ZrC-C _GS复合材料的质量烧蚀率降低了15.3%，耐热能力提高了45.6%，热膨胀系数明显降低在 200–1500 °C 的温度范围内。仿真结果表明，ZrC-C _GS的残余热应力和背温复合材料低于 ZrC-C _DS复合材料。该工作通过控制孔隙结构和分布，为设计和制备兼具消融和隔热性能的超高温复合材料提供了有效的策略。