中文摘要：

掺硅类金刚石（Si-DLC）薄膜表现出优异的摩擦学性能,在潮湿空气和高温中显示出极低的摩擦系数和很好的耐磨性,但是许多实验表明Sj-DLC膜的摩擦性能受其硅含量的影响很大.因此,本文采用分子动力学模拟的方法分别研究干摩擦和油润滑两种情况下不同硅含量的Si-DLC膜的摩擦过程.滑移结果表明干摩擦时DLC膜和掺硅DLC膜之间生成了一层转移膜,而油润滑时则为边界膜.因此干摩擦时的摩擦力明显大于油润滑时的摩擦力.少量添加硅确实能降低DLC膜的摩擦力,但是硅含量大于20%后对DLC膜的摩擦行为几乎无影响.干摩擦时硅含量对转移膜内键的数量影响很大,转移膜内CC键和CSi键都先增加后减少,滑移结束时几乎不含CSi键.

英文摘要：

Silicon-doped diamond-like carbon （Si-DLC） film is of significant interest for tribological effects, because it has a very low friction coefficient and possesses the potential to improve wear performance in humid atmospheres and at high temperatures. Many experimental results of the Si-DLC film show that its tribological property changes greatly with silicon content. In this paper, we use molecular dynamics （MD） simulation to study sliding friction processes between DLC and Si-DLC films under dry friction and oil-lubricated conditions separately. The results show that after sliding, a transfer film between the DLC and Si-DLC films is formed under the dry friction condition. In contrast, a boundary lubrication layer is found under the oil-lubricated condition. Therefore the friction forces on the dry friction condition are larger than those on the oil-lubricated condition. Small addition of silicon atoms can reduce the friction force of DLC films indeed, but it has little effect to the friction force when the silicon content is larger than 20%. There is a obvious effect of the silicon content on the bond number of transfer films under the dry friction condition, and CC bond and CSi bond both first increase and then decrease, there is almost no little CSi bond at the end of the sliding.