The influence of the nanosized asperity on the wear resistance of the single‐layer graphene (SLG) is investigated by an atomic force microscope. For the SLG on the polished diamond substrate, a 15 nm high asperity underneath it can cause a significant reduction of the critical contact pressure initializing the failure in its interior region from 43.75 to 8.31 GPa (calculated by the Derjaguin–Muller–Toporov model). The SLG fails at the inclined surface with a larger inclination angle around the bump region at first due to the increased shearing strength and the introduced lattice strain. Then, the fracture of graphene occurs at the newly formed step edges and rapidly propagates along the scanning path, which finally results in a complete failure of the SLG. The findings in this study reveal that the surface asperity on the substrate may be one of the factors that lead to the sharp discrepancy between the nanoscopically ultrastrong strength and the macroscopically weak wear resistance of graphene.

中文翻译：

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基底表面上的纳米凹凸激活单层石墨烯的内部失效

通过原子力显微镜研究了纳米级粗糙度对单层石墨烯（SLG）耐磨性的影响。对于抛光金刚石基材上的SLG，其下方15 nm高的粗糙度会导致临界接触压力显着降低，从而将其内部区域的破坏从43.75 GPa降低到8.31 GPa（由Derjaguin–Muller–Toporov模型计算）。由于增加的剪切强度和引入的晶格应变，SLG首先在围绕凸点区域具有较大倾斜角的倾斜表面处失效。然后，石墨烯的断裂发生在新形成的台阶边缘，并沿着扫描路径迅速传播，最终导致SLG完全失效。