Abstract Ultrahard nanotwinned diamond (nt-D) is an ideal material for next-generation high-precision, high-efficiency cutting tools, due to its high hardness, enhanced fracture toughness, and increased oxidation resistance temperature, when compared with natural diamond. However, a critical problem that limits the application of such material is the grinding and polishing of nt-D material into suitable shapes. In this study, we confirmed the feasibility of classical mechanical polishing for nt-D through amorphization transition. The effect of mechanical loading and the catalysis of Fe nano-particles work together, promoting the transformation of nt-D into a hard sp2-sp3 amorphous carbon. The surface of the amorphous carbon layer and the interface between amorphous carbon and nt-D were both smooth after polishing. The results are valuable for the mechanical processing and further applications of ultrahard nanotwinned diamond.

中文翻译：

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超硬纳米孪晶金刚石过渡到硬质sp2-sp3无定形碳的机械抛光

摘要 超硬纳米孪晶金刚石（nt-D）与天然金刚石相比，具有硬度高、断裂韧性强、抗氧化温度高等优点，是下一代高精度、高效切削刀具的理想材料。然而，限制这种材料应用的一个关键问题是将 nt-D 材料研磨和抛光成合适的形状。在这项研究中，我们证实了通过非晶化转变对 nt-D 进行经典机械抛光的可行性。机械负载的作用和 Fe 纳米粒子的催化作用共同作用，促进了 nt-D 向硬质 sp2-sp3 无定形碳的转化。抛光后的无定形碳层表面和无定形碳与nt-D的界面均光滑。