Lan Huiqing, Kato Takahisa
School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, No. 3 of Shangyuan Residence, Haidian District, Beijing 100044, China.
J Nanosci Nanotechnol. 2013 Feb;13(2):1063-7. doi: 10.1166/jnn.2013.6112.
Diamond-like carbon (DLC) films have been extensively studied over the past decades due to their unique combination of properties; in particular, silicon-doped DLC (Si-DLC) films are of significant interest for tribological effects, they had a very low friction coefficient and possessed the potential to improve wear performance in humid atmospheres and at higher temperatures. But many experimental results of the Si-DLC films showed that their tribological properties changed greatly on different silicon content. In the paper, molecular dynamics (MD) simulations were used to study microstructure of amorphous Si-DLC films and a sliding friction process between DLC and Si-DLC films on un-lubricated and oil-lubricated conditions respectively. The results show that silicon atoms are almost surrounded by carbon atoms in all Si-DLC films. The sp3/sp2 ratio in Si-DLC films increases with the increasing silicon content. After sliding, a transfer film between the DLC and Si-DLC films is formed on the un-lubricated condition. In contrast, a boundary lubrication layer is found on the oil-lubricated condition. Moreover, the friction forces on the un-lubricated condition are larger than those on the oil-lubricated condition.
在过去几十年中，类金刚石碳（DLC）薄膜因其独特的性能组合而受到广泛研究；特别是，掺硅DLC（Si-DLC）薄膜因摩擦学效应而备受关注，它们具有非常低的摩擦系数，并且在潮湿气氛和较高温度下具有改善磨损性能的潜力。但是许多关于Si-DLC薄膜的实验结果表明，它们的摩擦学性能会因硅含量的不同而发生很大变化。在本文中，分子动力学（MD）模拟分别用于研究非晶Si-DLC薄膜的微观结构以及DLC薄膜与Si-DLC薄膜在未润滑和油润滑条件下的滑动摩擦过程。结果表明，在所有Si-DLC薄膜中，硅原子几乎被碳原子包围。Si-DLC薄膜中的sp3/sp2比率随硅含量的增加而增加。滑动后，在未润滑条件下，DLC薄膜与Si-DLC薄膜之间形成转移膜。相比之下，在油润滑条件下发现了边界润滑层。此外，未润滑条件下的摩擦力大于油润滑条件下的摩擦力。
