Construction And Characterization Of Superhydrophobic Surfaces Of Three Transitional Metals On AZ31 Magnesium Alloy Surface

Inspired by the super-hydrophobic surface of plants in nature,functional surfaces with superhydrophobic properties have received extensive attention.Magnesium alloys are gradually coming into view because of their high surface contents,low density,high specific strength,good damping properties and excellent cutting performance.However,the poor corrosion resistance is a major problem faced by magnesium alloys,which greatly limited the application of magnesium alloys in various fields.The superhydrophobic surface on the surface of the magnesium alloy can effectively reduce the contact area between the substrate and the corrosive medium to solve this problem very well.In this dissertation,superhydrophobic membranes are fabricated on the surface of magnesium alloys by hydrothermal,pulling,chemical conversion film,immersion and chemical etching method.The composition,morphology and structure of the prepared samples were analyzed by EDS,SEM,FT-IR,XRD and other analytical methods.The contact angle test,friction and wear test,simulated seawater immersion test,electrochemical test(EIS and IE),anti-icing,long-term stability,anti-fouling and anti-corrosion properties of the prepared surface were explored in detail.Zinc oxide nanorods were fabricated on the surface of magnesium alloy by a combination of impregnation and hydrothermal methods,as well as a single-layer non-substrate flower-like nanostructured zinc oxide.Comparatively speaking,the zinc oxide nanorods are denser.The static contact angles of the two superhydrophobic surfaces can reach 150° or even close to 160°.In addition,the superhydrophobic film can remain in air for more than 7 months and it still has hydrophobic properties for droplets in different acidic solutions,which indicates the excellent long-term stability.Ni-P-NiO superhydrophobic surface was prepared on AZ31 magnesium alloy by electroless nickel plating,hydrothermal method and immersion method.By means of electroless nickel plating,a barrier layer is formed on the base of the magnesium alloy,which effectively prevents the contact between the outside world and the magnesium alloy substrate,and builds a superhydrophobic NiO surface on the surface of Ni-P to further strengthen the protection and the superhydrophobic nature of the magnesium alloy surface.The hydrophobicity is proved through theoretical calculations;friction and wear,chemical stability and long-term stability tests proved the good ability to adapt to harsh environments.The comparison experiment was performed by an electrochemical workstation and the film showed excellent corrosion resistance.A super-hydrophobic surface of Ag@MCM-41 was prepared on AZ31 magnesium alloy by soaking and liquid-phase chemical etching.After fluorination of magnesium alloys,the surface is more compact.The contact angles of the samples at different temperatures and different pH values are measured.Through friction and wear tests,it is proved that they had good anti-friction properties and the wear resistance of magnesium alloys is improved;it is verified by the hemocytometer test and anti-algae ability;through electrochemical impedance test,it is found that the super-hydrophobic surface has a higher resistance value,improving the corrosion resistance of magnesium alloys.