Investigation of the tribological properties of the different textured DLC coatings under reciprocating lubricated conditions

• Published in: Tribology international 2013-09, Vol.65, p.259-264
• Main Authors: Shum, P.W., Zhou, Z.F., Li, K.Y.
• Format: Article
• Language: English
• Subjects: Coatings; Density; Diamond-like carbon films; Dimpling; DLC; Friction; Laser; Reciprocating; Reduction; Surface texturing; Wear; Wear rate
• ISSN: 0301-679X; 1879-2464
• DOI: 10.1016/j.triboint.2013.01.012

In this study, we propose the use of laser surface texturing methods to improve the wear resistance of diamond-like-carbon (DLC) coatings. First, the application of dimples perpendicular to an engineering surface is introduced by using laser in a controlled manner. The solid DLC lubricant is subsequently deposited on the textured surface using the magnetron sputtering technique. In the experiments, the dimple densities were varied from 0 to 30%, and the dimple diameters were varied from 40 to 300μm. The effect of the geometric parameters on the wear performance was studied using a reciprocating sliding-wear tester under oil lubrication conditions. The results showed that the DLC coatings with the appropriate dimple density (10%) and diameter (∼100μm) demonstrated an obvious improvement in terms of the friction coefficient and wear rate compared with that of the un-textured DLC coatings. The experimental treatment produced respective reductions of 20% in friction and nearly 52% reduction of wear rate. This improvement could be explained by the action of reservoirs that enhance lubricant retention and trap the wear particles during sliding motions. In addition, the relationship between the dimple diameter, the contact width ratio and the wear performance is discussed. ► The sample with 10% dimple density produced an obvious drop in friction and wear. ► The sample with 100μm dimple diameter produced good wear performance. ► As the dimple ϕ to contact ϕ ratio is 1, the wear performance is the best.