Effects of Micro Dimple’s Topography Parameters on Wear Resistance of Laser Textured AlCrN Coating Under Starved Lubrication Condition

Abstract

Due to good impact wear performance and abrasion resistance, AlCrN coating has been widely used on stamping die. But because the tribological property of the surface is poor, in practical application, coating often wears or spalls. To furtherly enhance the coating's wear resistance, coating combined with laser surface textures was applied. In this study, micro dimples with different depths and diameters were fabricated on different samples and their depth-to-diameter ratios also varied. Reciprocating pin-on-disk tests under starved lubrication conditions were performed to compare samples' wear resistance. The wear morphology was observed under confocal microscopy and scanning electron microscope (SEM) with energy dispersive spectroscopy (EDS) to investigate the influence mechanism of topography parameters on wear resistance. The results showed that optimal topography parameters could be found to achieve the best wear resistance. When the depth-todiameter ratio was small, serious adhesive wear occurred due to insufficient ability of storing wear debris; when the ratio was large, the surface suffered severe adhesion wear due to poor lubrication condition. In addition, for micro dimples with small depth-to-diameter ratio, the coating on the dimple wall could cracked because of horizontal friction force. Furthermore, for dimple with large diameter, the dimple edge could interlock with the upper sample edge, causing serious wear. The contribution provided reference for the topography parameters selection of textured coating under starved lubrication conditions.

A Review on Friction Reduction by Laser Textured Surfaces in Internal Combustion Engines

“…The pin-on-disk measurements with starved lubrication found the optimal depth-to-diameter ration on 0.026. It is important to note that on shallow dimples the cavity can fill up quick with wear particles, while with large diameter dimples an interaction with the testing pin can damage the results [50].…”