Influence of Variable-Depth Groove Texture on the Friction and Wear Performance of GCr15–SiC Friction Pairs Under Water Lubrication

Surface texturing is an effective method for enhancing tribological properties through the dynamic pressure effect and secondary lubrication mechanism. This study developed and evaluated a variable groove profile texture that enhanced the bearing capacity, reduced the shear friction, and achieved effective water lubrication of a GCr15 ball–SiC disk friction pair interface. Based on a structural design analysis, the coefficient of friction, wear characteristics, and triboelectric voltages produced by different disk textures were evaluated in a series of experiments using scanning electron microscope images and energy dispersive spectrometer. The results indicated that a groove profile slanted downward towards the outside of the disk provided the best comprehensive antifriction and anti-wear performance under the considered low- and medium-speed conditions. This texture enhanced the radial conduction of lubricant through the groove via the dynamic pressure effect and collected and expelled the abrasive particles generated during friction via centrifugal and gravity forces, reducing the quantity of abrasive particles at the interface and decreasing the coefficient of friction. The elevated contact stress and localized heat generated at the edge of the groove texture stimulated iron migration and tribochemical reactions at the interface, forming a dense, wear-resistant lubricant film that decreased the wear on the ball and disk surfaces. Finally, the variable-depth groove texture boosted the surface charge density generated at the contact interface, increased the capability of the surface to adsorb the lubricating water film, and thereby enhanced the antifriction and anti-wear performance of the lubricated friction pair system.