For the successful application of boundary lubrication, detailed investigations about the influence of preparation process on molecular films are needed. In this paper, a specially designed device was used for the film preparation. The scanning electron microscope (SEM) combined with atomic force microscope (AFM) was employed to characterize the surface morphology and nanotribological behavior of molecular films. After the liquid phase deposition, molecular films are randomly and densely distributed over Ti-doped diamond-like carbon (Ti-DLC) substrates. Through rigorous surface treatments, island-like molecular films were finally achieved on substrate surfaces. The surface friction of molecular films is obviously lower than that of Ti-DLC surfaces. Then, pin-on-disk tribotests were performed to study the macrofriction behavior of molecular films under different preparation parameters. Based on the orthogonal experiment, the effect of five preparation parameters (solution weight percent, smearing force and processing time of three smearing steps) on initial friction coefficient of molecular films was investigated. The results indicated that the order of significance levels is as follows: processing time of the second smearing step > solution weight percent > processing time of step 1 > processing time of step 3 > smearing force. For the purpose of friction reduction, the appropriate level ranges are 0.75% (Solution), 2.5 N–15 N (Force), 1 min–10 min (Step 1), 1 min–2 min (Step 2) and 1 min, 2 min, 5 min and 15 min (Step 3). The initial friction coefficient under the optimized conditions is around 0.112, and the equilibrium friction coefficient is around 0.162, which is lower than that of unlubricated Ti-DLC substrates.

为了成功应用边界润滑，需要详细研究制备过程对分子膜的影响。在本文中，专门设计的设备用于制膜。结合原子力显微镜（AFM）的扫描电子显微镜（SEM）来表征分子膜的表面形态和纳米摩擦行为。液相沉积后，分子膜随机且密集地分布在掺Ti的类金刚石碳（Ti-DLC）衬底上。通过严格的表面处理，最终在基底表面上获得了岛状分子膜。分子膜的表面摩擦力明显低于Ti-DLC表面。然后，进行了磁盘销钉摩擦试验，以研究在不同制备参数下分子膜的宏观摩擦行为。在正交试验的基础上，研究了五个制备参数（溶液重量百分比，涂抹力和三个涂抹步骤的处理时间）对分子膜初始摩擦系数的影响。结果表明，显着性水平的顺序如下：第二次涂抹步骤的处理时间>溶液重量百分比>步骤1的处理时间>步骤3的处理时间>涂抹力。为了减少摩擦，适当的含量范围是0.75％（溶液），2.5 N–15 N（力），1分钟至10分钟（步骤1），1分钟至2分钟（步骤2）和1分钟， 2分钟，5分钟和15分钟（第3步）。