Molecular-scale tribology of amorphous carbon coatings: Effects of film thickness, adhesion, and long-range interactions
Molecular-scale tribology of amorphous carbon coatings: Effects of film thickness, adhesion, and long-range interactions
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DOI：
10.1021/ja0178618
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发表时间：
2002-06-19
影响因子：
15
通讯作者：
Harrison, JA
中科院分区：
文献类型：
--
作者：
Gao, GT;Mikulski, PT;Harrison, JA
采用经典的分子动力学模拟方法研究了氢终止的金刚石（111）相对表面与无定形无氢碳膜金刚石（111）表面滑动接触时的原子尺度摩擦磨损。两个膜，具有大致相同的比例的sp（3）到sp（2）的碳，但不同的厚度，已被检查。两种系统在所检查的载荷范围内给出相似的平均摩擦。在临界载荷以上，发生一系列摩擦化学反应，导致膜的显著重构。这种重组类似于宏观摩擦实验中观察到的“磨合”，并减少了摩擦。通过改变配合面的饱和度来检查探针（配合面）和样品之间的粘附对摩擦的贡献。通过减少氢终止来降低配合面饱和度，从而增加摩擦。最后，长程相互作用对摩擦的贡献进行了研究，通过使用两个势能函数，不同的只是在他们的长程力，以检查在同一系统中的摩擦。
Classical molecular dynamics simulations have been conducted to investigate the atomic-scale friction and wear when hydrogen-terminated diamond (111) counterfaces are in sliding contact with diamond (111) surfaces coated with amorphous, hydrogen-free carbon films. Two films, with approximately the same ratio of sp(3)-to-sp(2) carbon, but different thicknesses, have been examined. Both systems give a similar average friction in the load range examined. Above a critical load, a series of tribochemical reactions occur resulting in a significant restructuring of the film. This restructuring is analogous to the "run-in" observed in macroscopic friction experiments and reduces the friction. The contribution of adhesion between the probe (counterface) and the sample to friction was examined by varying the saturation of the counterface. Decreasing the degree of counterface saturation, by reducing the hydrogen termination, increases the friction. Finally, the contribution of long-range interactions to friction was examined by using two potential energy functions that differ only in their long-range forces to examine friction in the same system.