| Magnesium alloy material has the advantages of low density,high specific stiffness,high damping coefficient,easy recycling,etc.It has a wide range of market application prospects and potential in the aerospace,automotive,electronic information and other industries.However,the high chemical activity of magnesium alloys is easily corroded by other corrosive media,which seriously hinders the development and application of magnesium alloy materials.In recent years,it has been found that superhydrophobic surfaces can improve the corrosion resistance of magnesium alloy surfaces and also impart many composite application properties to the material surfaces.In this paper,the superhydrophobic surface was prepared on the surface of magnesium alloy material by nanosecond laser etching method combined with stearic acid anhydrous ethanol low surface energy solution,and the corrosion resistance of magnesium alloy material was improved.The main research and findings of this paper are as follows:1.The microstructures were prepared by laser etching on the surface of magnesium alloy substrate,and then modified by stearic acid anhydrous ethanol solution with low surface energy to investigate the effects of different parameters on the surface morphology,roughness and wettability of magnesium alloy.The etching power is too low or the etching speed is too high to obtain good wetting performance;too high or too low etching power will lead to irregular microstructure of the magnesium alloy surface.When the etching power is 10W and the etching speed is 150mm/s,the regular rough structure and the ideal wetting property can be prepared.With the increase of etching times leading to the increase of microstructure,the contact angle gradually decreases.The most stable superhydrophobicity was achieved at a spacing of 0.06 mm.Combining the surface morphology and wettability analysis,the superhydrophobic properties of the magnesium alloy surface were most stable when the laser etching power was 10W,the etching speed was 150mm/s,the number of etchings was 2 and the etching spacing was 0.06mm.2.The corrosion resistance of the superhydrophobic magnesium alloy was investigated and found by electrochemical workstation test.In the polarization curve test,the self-corrosion potential of the superhydrophobic magnesium alloy sample increased by 0.16 V compared with the original magnesium alloy sample,and the corrosion current density decreased from 1.084×10-4A/cm~2 to3.033×10-6A/cm~2.The corrosion resistance of the superhydrophobic magnesium alloy surface was improved,and the corrosion retardation rate reached 97.2%.In the electrochemical impedance spectroscopy test,the tolerance arc radius of the superhydrophobic magnesium alloy samples was larger than that of the other samples,indicating that the corrosion resistance of the superhydrophobic magnesium alloy samples was improved.The wettability of the samples after the electrochemical test showed that the superhydrophobic samples still maintained good superhydrophobic.3.Test the application performance of superhydrophobic magnesium alloy:through the droplet impact magnesium alloy sample,found that the water droplet can make bouncing behavior on the surface of superhydrophobic magnesium alloy sample,indicating that the superhydrophobic sample shows low adhesion to the droplet.The stability performance of magnesium alloy in acid and alkali solution,high and low temperature extreme conditions for experiments,magnesium alloy samples in addition to strong acid environment are to maintain superhydrophobic performance;after friction 1000mm,the sample surface is still greater than140°showing hydrophobic performance,with good mechanical stability performance.In the self-cleaning experiment and freezing experiment,it showed excellent self-cleaning performance and delayed freezing performance.And the superhydrophobic surface shows good stability performance in air. |
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