不同工作环境下CrN涂层的摩擦磨损性能

为探索研究CrN硬质涂层材料在复杂工况条件下的使用特性,采用多弧离子镀技术在304不锈钢基板表面沉积CrN薄膜,并分析了其在不同工作环境下的摩擦磨损性能。采用X射线衍射仪(XRD)分析了薄膜的相结构,采用冷场发射扫描电子显微镜(FESEM)观察了薄膜的微观形貌,并用其能谱分析(EDS)功能分析了磨痕磨粒的化学成份,采用纳米压痕仪和纳米划痕仪测试了薄膜的机械性能。摩擦试验研究结果表明,在干摩擦环境中,随氧分压增高,CrN薄膜摩擦因数和钢球磨损率均增大,说明粘着磨损和氧化反应形成第三体磨粒磨损应是CrN薄膜发生破坏的主要原因;在真空环境中,CrN薄膜的摩擦因数维持在0.3左右;增大工作环境湿度,CrN薄膜的摩擦因数降低;在去离子水浸润环境中其摩擦因数可降低至0.1左右,说明CrN薄膜可应用于高湿度环境或真空环境中的减摩抗磨防护。

Friction and Wear Properties of CrN Films in Different Working Environments

To investigate the performance of CrN hard coatings working in harsh environment, the CrN films were deposited onto polished SUS304 substrates using multi-arc ion plating. Friction and wear properties of the CrN films were measured in different environmental conditions. The phase structure of the films was analyzed by X-ray diffraction (XRD), and their microscopy morphology were observed by cold field emission scanning electron microscopy (FESEM), and the chemical compositions of the abrasive particles and wear track were detected by equipped energy dispersive spectroscopy (EDS). The mechanical properties of the films were tested by nano-indentation instrument and nano-scratch instrument. The friction and wear properties of CrN films working in different environments were analyzed. The results show that: both the friction coefficient and the wear rate of the coupled steel ball increased with the increment of the oxygen part pressure when the films work in dry environment. It can be ascribed to the abrasive friction and oxidation of the abrasive particles in the sliding process. In vacuum environment, the friction coefficient of the CrN films decreases to 0.3. The friction coefficient of the CrN films declines with increasing the humidity of the working environment. As the coupled pairs worked under the lubrication of deionized water, the friction coefficient can be reduced to about 0.1. It can be concluded that CrN films can be used in high humidity environment or vacuum environment.