Laser Preparation And Performance Study Of Micro-structured Super-hydrophobic Functional Surface

Aluminium alloy and copper are widely used in many fields.Due to its poor anti-corrision and tribological properties,the development of these materials are restricted.Traditional method?such as surface coating?can effectively protect the metal and reduce the friction and wear,but the operation is complex,the bonding strength of the substrate is poor and the environment is easy to pollution.In recent years,the bionics superhydrophobic surface with special micro/nano structures can store large amounts of air and prevent water molecules penetrate into it.Then improve the wear resistance and corrosion resistance.This paper is mainly use aluminium alloy and copper as substrates to produce a series of micro/nano structures using laser texturing,combined with silane treatment to obtain superhydrophobic surface.Research the surface wettability,tribological properties and corrosion resistance systematically.Findings:?1?Different types of microstructures were prepared on aluminium alloy surfaces through adjusting laser processing parameters.When the scanning speed is low,the number of laser pulses in the unit area increases,forming a continuous and obvious micro-groove structures.With the increase of scanning speed,the repetition rate of laser spot gradually tends to negative,forming crater-like microstructures.Lower laser power requires a higher number of laser pulses to form similar structures that can be formed by higher laser power.The laser processed surface was modified with stearic acid to form a superhydrophobic surface.The surface with rougher microstructures can bring more hydrophobic.?2?Using a UV laser marking machine to fabricate micro-groove structures with different scanning space on aluminium alloy surface,to explore the critical conditions of conversion between Cassie and Wenzel states.When the scanning interval is 200?m,a droplet can overcome the energy barrier form the conversion between the two states.Compared with the smooth surface,the superhydrophobic surface has low surface energy.?3?Study the tribological properties and corrosion resistance on different structed Al surface,the results show that the friction coefficient of micro-dimple and micro-groove structures is about 0.2,the frictional resistance is good.However,the micro-pillar structures have more convex parts,the contact area between the friction pairs is less and the capable of carrying capacity is bad,so the frictional resistance is worse.Compared with the smooth surface,the superhydrophobic Al surface own higher corrosion potential and lower corrosion current density.?4?Through the study of the anti-corrosion and tribological properties on the superhydrophobic brass surface,it is found that surface has better anti-corrision and tribological properties.When the scanning speed is 10 mm s^-1,the friction coefficient is lower then others.Compared with the smooth surface,the superhydrophobic brass surface own higher corrosion potential and lower corrosion current density.