Effect of Textured Surface on Friction and Wear Properties of 45 Steel

A highly matched friction finite element model was established, and the changes of the texture surface stress field and temperature field were analyzed during the sliding process. It was hoped to characterize the antifriction performance of texture. Three surface textures (i.e. circle, triangle and square) were processed on the surface of 45 steel by using laser processing technology. The effect of texture morphology on friction and wear were studied through the HT-1000 friction and wear testing machine, and the wear investigated was analyzed by scanning electron microscope. The results showed that the existence of texture reduced the contact area between the pin and the disk, which made the contact between the pin and the disk became the contact between the pin and the texture edge.When the pin slided through a texture on the disk, the surface contact stress changed from low to high, and then from high to low. Stress concentration occurred at the edge, and the stress on the edge of the texture was elliptical, and diffused from the center to the surrounding. In three textures, the square had highest stress values, followed by the circle and the triangle. Due to the geometric factors of texture shape, the right angle structure had an obvious cutting effect on the pin, which increased the movement resistance of the pin. So the stress in the contact area was the largest for the square texture. The triangle texture had a small acute angle structure which had limited cutting force on the pin, and bears had less pressure and movement resistance. Therefore, the triangular textured surface had the minimum stress. While the stress changes and the temperature field distribution of the three textured surfaces were also different. When the pin slided through a texture on the disk, the temperature in the center of the contact area decreased, and the high temperature tended to concentrate mainly on the texture edge. The stress concentration caused by the pressing action of the texture edge on the pin caused the surface temperature of the texture disk to rise. The triangular texture surface had the lowest temperature rise. The reason for this result was that the existence of texture increased the surface heat dissipation area, and the heat generated during friction could be dissipated in time to reduce the temperature of the contact area of the texture disk. The friction coefficient and the degree of fluctuation of the smooth surface were higher than those of the textured surface under the same test conditions. From the morphology of worn surface, it was found that there were a lot of wear debris and deep furrows on the smooth surface; a large amount of wear debris was stored in the pits on the textured surface, and there were multiple layers of wear debris at the texture edge. It was demonstrated that the surface texture could store third-body wear debris, reduce furrowing, and thus it had better tribological properties than smooth surfaces. The model with the best friction reduction was the triangular texture.