Tribological Performance Evolution of Circular-Textured Surface Embedded with Paraffin Regulated by Texture Geometric Dimensions

The positive effect of paraffin on lowering the temperature, friction coefficient, and wear mass of a circular-textured surface has been proved. On this basis, this study is meant to reveal the influence of surface density and diameter of circular texture on the lubricating effect. It was found that the friction coefficient and wear kept decreasing as surface density increased from 6.8% to 24.2% due to increasing dynamic pressure up to 285 Pa. However, as surface density further increased to 40.1%, the tribological properties were weakened due to high contact stress from a smaller contact area. On the basis of the optimized surface density of 24.2%, the friction coefficient and wear kept decreasing due to increasing dynamic pressure up to 326 Pa as the diameter of the circular texture increased from 400 μm to 550 μm. When the diameter of the circular texture increased to 650 μm, the tribological properties of the textured surface were weakened. Compared with a depth of 500 μm, a depth of 1000 μm could store more paraffin, providing better temperature-reducing and lubricating effects. Ultimately, the minimum temperature of 40.78 °C, minimum friction coefficient of 0.063 ± 0.003, and minimum wear loss of 0.70 ± 0.10 mg were obtained under the optimal texture surface density, diameter, and depth of 24.2%, 550 μm, and 1000 μm, respectively.