Effect of the patterned cylindrical dimple array on the tribological performance of lubricated point-contacts

This paper presents the experimental results for oil lubricated ball/disc point-contact with prepared patterned dimples on functional surface. The patterned dimples are produced by mircosecond laser and characterized by the Dual Mode 3D Profilometer. Tribological experiments are conducted on the commercial UMT-III tribo-meter. Stribeck-like curves are obtained to depict the transition of lubrication regime and electrical contact resistance is utilized to qualitatively characterize the lubrication regime. The test results show that compared with the non-textured surfaces, the friction coefficient firstly decreases then increases when the dimple depth is reduced from 30 μm to zero, and gets minimal value at about 10 μm. The coverage ratio and size of the patterned dimples also have effect on the friction coefficient under lubricated point-contact conditions. It can be found that there exist optimal dimple parameters for reduction of friction coefficient.