Influence of Cross-Grooved Texture Shape on Tribological Performance under Mixed Lubrication

Surface texture plays an important role in improving the tribological properties of materials. In this paper, the effect of different shapes (i.e., triangle, square, hexagon, round) on the tribological performance of cross-grooved texture was investigated. First, the mixed lubrication condition was used for the pin-on-disc rotating sliding tests. Then, the stress distribution of the four textures was analyzed to better explain the experimental results. Overall, the hexagon-textured specimens exhibited lower friction coefficients than the other shape-textured specimens under the examined conditions. Simulation results indicate that the contact stress can be reduced on the surface of hexagon-textured specimens, and this leads to a better oil film for lubrication. Furthermore, the hydrodynamic lubrication stood out with the increase of speeds to 250 rpm. However, as the test loads further increased, the film thickness decreased, resulting in the increase in the asperity contact areas, which dropped the above advantage of hexagon-textured specimens. This study would be beneficial for the texturing tribological and lubrication design.