Surface defects of tetrahedral amorphous carbon coatings are typically defined as spikes, droplets, and pores. In this study, a hybrid filtering method using a fixed physical and electrical filter (duct bias voltage) in a filtered cathodic vacuum arc system was used to control the surface defects. The introduction of the duct bias can control to trap the negatively charged macro-particles which is transported to the base material due to a floating potential and duct wall sheath that depend on the positive voltage. The applied positive duct bias voltage was 10, 15, 20, and 30 V. The results of this experiment revealed that as the duct bias voltage increased up to 30 V, the spikes and droplets were almost completely removed on the tetrahedral amorphous carbon surface and only the pores remained. The pores could not create a rough surface for the relative motion between interfaces due to which the friction coefficient increased as the duct bias voltage increased up to 30 V. It was concluded that the spike and droplet defects were positive elements and were required to introduce a carbon-based transfer interface and maintain a stable coefficient of friction.

四面体无定形碳涂层的表面缺陷通常定义为尖峰，液滴和孔。在这项研究中，使用混合的过滤方法，在过滤的阴极真空电弧系统中使用固定的物理和电气过滤器（导电偏置电压）来控制表面缺陷。引入管道偏压可以控制捕获带负电荷的大颗粒，这些颗粒由于依赖于正电压的浮动电位和管道壁护套而被输送到基础材料。施加的正管道偏置电压为10、15、20和30V。该实验的结果表明，随着管道偏置电压增加到30 V，四面体无定形碳表面上的尖峰和液滴几乎被完全去除。仅保留毛孔。