Li Ruiyun, Yang Xing, Wang Yongfu, Zhang Junyan, Li Jiangong
State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Science, Lanzhou 730000, P. R. China.
School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, P. R. China.
ACS Appl Mater Interfaces. 2021 Jan 20;13(2):3397-3407. doi: 10.1021/acsami.0c18900. Epub 2021 Jan 7.
Presently, approaches to achieve superlubricity for diamond-like carbon (DLC) films rely heavily on the film deposition techniques and parameters, such as other nonmetallic element incorporation and structure optimization. In this work, we report a new feasible pathway to achieve superlubricity for DLC films, which is not dependent on the film preparation parameters but rather on the external effects, i.e., sliding interfacial addition of metal nanoparticles (Cu and Ni). The approach controls the structures of wear products by the introduction of metal nanoparticles and the subsequent effect of metal catalysts, to in situ form graphene-coated particles without impacting the overall performances of the films. Through detailed experimental investigations combined with density functional theory (DFT) simulations, graphitic encapsulation and electronic shielding of metal nanoparticles are responsible for the dramatic changes at the frictional interface leading to metal-carbon interfacial superlubricity. We expect that the approach will enrich the understanding of the lubrication mechanism of DLC films and promote the DLC films' superlubricity toward applications.
目前，实现类金刚石碳（DLC）薄膜超润滑性的方法严重依赖于薄膜沉积技术和参数，如其他非金属元素的掺入和结构优化。在这项工作中，我们报告了一种实现DLC薄膜超润滑性的新可行途径，该途径不依赖于薄膜制备参数，而是依赖于外部效应，即金属纳米颗粒（铜和镍）的滑动界面添加。该方法通过引入金属纳米颗粒和金属催化剂的后续作用来控制磨损产物的结构，以原位形成石墨烯包覆颗粒，而不影响薄膜的整体性能。通过详细的实验研究结合密度泛函理论（DFT）模拟，金属纳米颗粒的石墨化封装和电子屏蔽是摩擦界面发生显著变化从而导致金属-碳界面超润滑性的原因。我们期望该方法将丰富对DLC薄膜润滑机制的理解，并推动DLC薄膜超润滑性的应用。
