Abstract The sea urchin tooth, a natural grinding tool, exhibits prominent wear resistance during food biting and rock boring, while being almost entirely composed of intrinsically brittle CaCO3. Revealing its underlying wear tolerance mechanisms may provide significant inspiration for the potential application of low-cost, brittle structural materials (e.g., ceramics). To this end, the present study investigated the mechanical and wear behaviour of the stone in Glyptocidaris crenularis tooth using nanoindentation, scanning electron microscopy and transmission electron microscopy. The results show that the stone exhibits superior wear resistance than geological calcite and dolomite though moderate in hardness. Owning to its sophisticated fiber-reinforced architecture, confined damage is achieved via multiple deformation mechanisms, thus maintaining the structural and functional integrity of the tooth.

中文翻译：

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海胆齿的极端耐磨性

摘要 海胆齿是一种天然研磨工具，在咬食和凿岩过程中表现出突出的耐磨性，同时几乎完全由本质上脆的CaCO3 组成。揭示其潜在的耐磨损机制可能为低成本、脆性结构材料（例如陶瓷）的潜在应用提供重要启发。为此，本研究使用纳米压痕、扫描电子显微镜和透射电子显微镜研究了 Glyptocidaris crenularis 牙齿中结石的机械和磨损行为。结果表明，该石材虽然硬度适中，但耐磨性优于地质方解石和白云石。由于其复杂的纤维增强结构，有限的损坏是通过多种变形机制实现的，