ZrB<sub>2</sub>-Based “Brick-and-Mortar” Composites Achieving the Synergy of Superior Damage Tolerance and Ablation Resistance
Yehong Cheng, Yumin An, Yaxiong Liu, Qiang Wei, Wenbo Han, Xinghong Zhang, Peng Zhou, Chuncheng Wei, Ning Hu
Abstract
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.