Experimental study on the tribological performance of fractal-like textured surface under mixed lubrication conditions

• The friction coefficients of the fractal-like textured surfaces are 48.3% smaller than that of untextured surface.
• The friction reduction effect of fractal textured surface is prominent than that of normal regular textured surface.
• The friction reduction effects of fractal and fractal-like textured surface are sensitive to the operating conditions.

The effect of surface texturing on reducing friction is studied experimentally in this paper. Two types of fractal-like textures and their corresponding regular distribution textures have been fabricated on the surface of AISI1045 steel using a pulse laser, and reciprocating sliding tests were performed on a variable load tribometer (VLT). Friction coefficient of textured surfaces were investigated under various depths and operating conditions. The results show that surface texturing is important for reducing friction. Compared with untextured surface, the textured surface with a depth of 4.7 μm and sliding speed of 153.3 mm/s can reduce friction coefficient up to 48.3%. The fractal-like textured surface has a more effective friction reduction effect than regular distribution textured surface. Comparison of Sierpiński carpet textured surface and circular-based Sierpiński carpet textured surface was studied, and the conclusion was drawn that friction coefficient of the former is smaller than that of the latter under lower sliding speed, however, the conclusion is just the opposite for high sliding speed.