The intrinsic brittleness and poor damage tolerance of ultrahigh-temperature ceramics are the key obstacles to their engineering applications as nonablative thermal protection materials. Biomimetic layered or “brick-and-mortar” hybrid composites composed of alternative strong/weak interfaces exhibit excellent strength and high toughness; however, the commonly used interfacial materials are weak and have poor thermal stability and ablation resistance, which strictly limit their use in high-temperature and oxidative environments. In this work, ZrB₂-based “brick-and-mortar” hybrid ceramics were constructed with a hierarchical biomimetic design to improve the fracture resistance and damage tolerance. ZrB₂–20vol %SiC ceramics containing 30 vol % reduced graphene oxide nanosheets were used as the weak interface to increase crack growth resistance without destroying the excellent ablation resistance. Finally, the ZrB₂-based “brick-and-mortar” composites achieve the synergy of superior damage tolerance and ablation resistance.

中文翻译：

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基于ZrB2的“砖混砂浆”复合材料，具有出色的耐损伤性和抗烧蚀性。

超高温陶瓷的固有脆性和很差的损伤承受能力是它们作为非烧蚀热防护材料在工程应用中的主要障碍。由可替代的强/弱界面组成的仿生层状或“砖混”杂化复合材料表现出出色的强度和高韧性。然而，常用的界面材料较弱，并且热稳定性和耐烧蚀性较差，这严格限制了它们在高温和氧化环境中的使用。在这项工作中，以分级仿生设计构造了基于ZrB ₂的“砖和砂浆”混合陶瓷，以提高抗断裂性和损伤耐受性。ZrB ₂包含30％（体积）还原氧化石墨烯纳米片的–20％（体积）SiC陶瓷用作弱界面，以增加抗裂纹扩展性，而又不破坏其优异的抗烧蚀性。最后，基于ZrB ₂的“砖和砂浆”复合材料可实现优异的耐损伤性和抗烧蚀性。