Effects of texture diameter and depth on the tribological performance of DLC coating under lubricated sliding condition

In this study, the effect of surface texturing parameters on the tribological performance of amorphous hydrogenated diamond-like carbon (DLC) under oil lubrication has been investigated. Micro dimples were created on a substrate by using a picosecond laser. After surface texturing was performed, amorphous hydrogenated diamond-like carbon (DLC) coating was deposited through magnetron sputtering. Dimple diameter varied from 50 mu m to 300 mu m, and dimple depth varied from 6 mu m to 30 mu m. Results show that at respective dimple diameter and depth of 100 pin and 6 mu m, surface texturing improved the tribological performance of the amorphous hydrogenated DLC coating. Whereas, at a higher dimple diameter of 300 mu m and dimple depth of 30 mu m, the tribological performance of textured amorphous hydrogenated DLC was worse than that of un-textured amorphous hydrogenated DLC. The performance enhancement in the case of dimple diameter and depth of 100 mu m and 6 mu m can be due to micro textures, which can serve as a lubricant reservoir at the interface during sliding and remove wear particles from the contact. However, this beneficial mechanism could be obtained at an optimum texture diameter and depth. (C) 2015 Elsevier B.V. All rights reserved.