Femtosecond laser processing of micro texture and experimental study on friction and wear

In order to improve the surface friction properties of 7075 aluminum alloy, micro textures with different morphology and spacing were processed on the surface of 7075 aluminum alloy by femtosecond laser. The size and morphology of laser processing texture were tested by laser confocal microscope, and the parameters of laser processing micro texture were optimized. The results show that due to the different characteristics of oxide layer and internal material on the surface of aluminum alloy, micro texture morphology cannot be processed on the surface when the single pulse energy is too small; When the single pulse energy is too large, the texture depth is too large, which will affect the lubrication and drag reduction performance. The GF-I reciprocating friction and wear tester was used for friction and wear test to explore the area ratio of the optimal drag reduction performance of each micro texture under the load of 0.07m/s and 40n. The experimental results show that the friction coefficient is the smallest when the area ratio of each micro texture morphology is about 8%. In the regular hexagon, the micro texture spacing is 400 μm has the best drag reduction effect, and the drag reduction rate is 36.76% compared with the non textured surface.