Finding the optimum balance between strength and toughness, as well as acquiring reliable thermal shock resistance and oxidation resistance, has always been the most concerned topic in the discussion of ultra-high temperature ceramic composites. Herein, PyC modified 3D carbon fiber is used to reinforce ultra-high temperature ceramic (UHTC). The macroscopic block composite with large size is successfully fabricated through low temperature sintering at 1300 °C without pressure. The prepared PyC modified 3D C_f/ZrC-SiC composites simultaneously possess excellent physical and chemical stability under the synergistic effect of PyC interface layer and low temperature sintering without pressure. The fracture toughness is increased in magnitude to 13.05 ± 1.72 MPa·m^1/2 accompanied by reliable flexural strength of 251 ± 27 MPa. After rapid thermal shock spanning from room temperature (RT) to 1200 °C, there are no visible surface penetrating cracks, spalling, or structural fragmentation. The maximum critical temperature difference reaches 875 °C, which is nearly three times higher than that of traditional monolithic ceramics. The haunting puzzle of intrinsic brittleness and low damage tolerance are resolved fundamentally. Under the protection of PyC interface layer, the carbon fibers around oxide layer and matrix remain structure intact after static oxidation at 1500 °C for 30 min. The oxide layer has reliable physical and chemical stability and resists the erosion from fierce oxidizing atmosphere, ensuring the excellent oxidation resistance of the composites. In a sense, the present work provides promising universality in designability and achievement of 3D carbon fiber reinforced ceramic composites.

寻找强度和韧性之间的最佳平衡，获得可靠的抗热震性和抗氧化性，一直是超高温陶瓷复合材料讨论中最受关注的话题。在此，PyC 改性 3D 碳纤维用于增强超高温陶瓷 (UHTC)。通过1300℃无压力低温烧结成功制备了大尺寸宏观块状复合材料。在PyC界面层和低温无压烧结的协同作用下，制备的PyC改性3D C _f /ZrC-SiC复合材料同时具有优异的物理和化学稳定性。断裂韧性大幅提高至13.05±1.72 MPa·m ^1/2伴随着可靠的弯曲强度 251 ± 27 MPa。在从室温 (RT) 到 1200 °C 的快速热冲击之后，没有可见的表面穿透裂纹、剥落或结构碎片。最大临界温差达到875℃，比传统整体陶瓷高近三倍。从根本上解决了固有脆性和低损伤容限的困扰。在 PyC 界面层的保护下，氧化层周围的碳纤维和基体周围的碳纤维在 1500°C 静态氧化 30 分钟后仍保持结构完整。氧化层具有可靠的物理和化学稳定性，能抵抗剧烈氧化气氛的侵蚀，保证了复合材料优异的抗氧化性。从某种意义上说，