The present paper proposes a new treatment method for diamond-like carbon (DLC) coatings using electric discharge. DLC coatings exhibit excellent mechanical and tribological properties due to their unique carbonaceous structure. Several surface treatment methods were presented to achieve short running-in and low friction. However, in-situ surface treatment is needed to extend the life of machines and maintain their performance. Here, we propose an electric discharge treatment with a simple electrical circuit. As a result, the friction coefficient drastically drops from 0.3 to 0.11. Interestingly, the drop starts shortly after the discharge starts. Consequently, the running-in is shortened to about 6-m sliding compared to no discharge condition, which does not show any running-in more than 68-m sliding. Raman analysis reveals that a transfer layer on the ball surface is composed of carbonaceous material and the structure exhibits graphite-like characteristics. However, there is visible damage on the DLC surface. Another friction test shows a very low friction coefficient of 0.04 using a transfer layer-covered ball and a new DLC disk with a smooth surface. In conclusion, the combination of a transfer layer and smooth DLC surface is needed to exhibit excellent tribological performance, indicating the importance of less damage treatment. Next, pulse discharge treatment is demonstrated to achieve less damage to the DLC coating. As a result, the pulse discharge method reduces friction and surface damage. In conclusion, the proposed treatment methods using electric discharge not only show the potential for reducing friction, but also the feasibility of in-situ treatment during machine operation.

本文提出了一种利用放电对类金刚石碳（DLC）涂层进行处理的新方法。DLC涂层由于其独特的碳质结构而具有出色的机械和摩擦学性能。提出了几种表面处理方法以实现短磨合和低摩擦。但是，需要进行原位表面处理以延长机器的使用寿命并保持其性能。在此，我们提出一种具有简单电路的放电处理方法。结果，摩擦系数从0.3急剧下降到0.11。有趣的是，放电开始后不久便开始下降。因此，与没有放电的情况相比，磨合被缩短到大约6 m的滑行，没有超过68 m的滑移。拉曼分析表明，球表面上的转移层由碳质材料组成，并且该结构表现出类似石墨的特性。但是，DLC表面有明显的损坏。另一个摩擦测试表明，使用覆盖有转移层的球和具有光滑表面的新型DLC盘，摩擦系数仅为0.04，非常低。总之，需要将转移层和光滑的DLC表面结合起来以表现出优异的摩擦学性能，这表明减少损伤处理的重要性。接下来，证明了脉冲放电处理对DLC涂层的损害较小。结果，脉冲放电方法减少了摩擦和表面损伤。总之，所提出的使用放电的处理方法不仅显示出减少摩擦的潜力，