Superhydrophobic Anti-icing Coating On The Surface Of 5083 Aluminum Alloy

5083 aluminum alloy,as a typical non-heat treatment type aluminum alloy,is widely used in the manufacture of ship hulls as well as aircraft and vehicles due to its excellent performance.However,the surface of aluminum alloys in extremely cold environments is highly susceptible to icing,which can cause serious economic losses in some special cases.Superhydrophobic surfaces,as one of the passive anti-icing methods,have been widely noticed because of their simple design and remarkable effect.In this paper,a superhydrophobic anti-icing coating was successfully constructed on the surface of 5083aluminum alloy by using a combination of chemical etching and anodic oxidation,and modified with fatty acid-based low surface energy modifiers,and the effect of the relevant process on the hydrophobic performance of the coating was systematically investigated.The effect of roughness and surface energy on the anti-icing performance of the superhydrophobic coating was investigated.First,superhydrophobic coatings with a contact angle of 156.7±0.5°and a roll angle of only 1°were successfully constructed on the surface of 5083 aluminum alloy using anodic oxidation,chemical etching,chemical etching followed by anodic oxidation and anodic oxidation followed by chemical etching,respectively.Subsequently,the effects of chemical etching time,etching temperature,etchant concentration;anodizing solution type,oxidation time,oxidation current density and modifier type and concentration on the hydrophobic properties of superhydrophobic coatings were investigated.The results showed that the effects of chemical etching time,etching temperature,etchant concentration,anodic oxidation time and oxidizing solution concentration on the superhydrophobic properties of the coatings were similar,i.e.,the contact angle of the coating showed a trend of first increasing and then decreasing with the increase of the parameters.In contrast,the addition of oxalic sulfate at low concentration causes a certain degree of decrease in the hydrophobic performance of the coating.The modifier concentration is different,i.e.,the contact angle of the coating increases with increasing concentration and then does not change.The effect of modifier type and anodic current density on the hydrophobic properties of superhydrophobic coatings is small and almost negligible.Based on the above study,superhydrophobic coatings with similar contact angles and different roughness were successfully prepared by different current density processes.The anti-icing performance was tested,and it was found that the anti-icing performance of the coatings tended to increase and then decrease when the roughness increased further,with the best sample having a roughness of 2.09μm.The ice adhesion of the superhydrophobic coating was only 5.97±1.21 KPa,which was much lower than that of the bare metal surface,and the results of the mechanical cycle de-icing/icing test also showed good durability.At the same time,the superhydrophobic coatings with different roughnesses showed good mechanical durability and corrosion resistance,and the lower the roughness,the better the corrosion resistance.At the same time,superhydrophobic coatings with similar contact angles and different surface energies were prepared using modifiers with different carbon chain lengths,and the effect of surface energy on the anti-icing performance of superhydrophobic coatings was investigated on this basis.The results showed that the lower the surface energy,the better the anti-icing performance of the superhydrophobic coating.When the surface energy was0.83m J/m~2,the complete icing time of the superhydrophobic coating reached 918 s,and the ice adhesion was only 3.98±1.35 KPa.Meanwhile,the results of corrosion resistance tests on the coating showed that the effect of surface energy on the corrosion resistance of the superhydrophobic coating was small and almost negligible.