Preparation And Mechanism Research Of Anti-Corrosion-Self-Cleaning Functional Film On The Surface Of Aluminum Alloy By Electrodeposition

Aluminum alloy plays an important role in contemporary manufacturing with its high specific strength,low density and excellent electrical conductivity.moreover,the standard electrode potential of Al alloy is relatively negative,the chemical properties are active,and it is highly susceptible to corrosion by corrosive ions to cause corrosion reactions.The economic losses caused by the corrosion of aluminum alloys are shocking every year.So as to solve this problem and improve the corrosion resistance of aluminum alloy.In this paper,a functional protective coating that integrates anti-corrosion,anti-fouling and self-cleaning is prepared by treating the hydrophilic aluminum alloy surface.Lauric acid(LA)was chosen as the film former and cerium nitrate was chosen as the conductive salt in this paper.Electrodeposition is used to prepare a hydrophobic corrosion-resistant film on the aluminum alloy surface.And the SEM,WCA,EDS,FT-IT,EIS and salt spray test techniques are used to study the film,the results is considered the LA film is covered the surface of the aluminum alloy with a feather-like structure.The corrosion inhibition efficiency of the film reached 95.76%,and in the salt spray test,the corrosion point appeared for 8 days.Computational chemistry studies shown that aluminum alloy and LA are connected by C-O-Al chemical bonds,the-COOH of LA is deposited on the surface of aluminum alloy by chemical adsorption,the alkyl groups are arranged in outward manner.Moreover,a LA/r GO composite film is prepared on the surface of aluminum alloy through the combination of electrodeposition and r GO doping.SEM,EDS,XPS,FT-IT and Raman tests are used to characterize the morphology and composition of the film.Electrochemical tests,contact angle tests,salt spray tests and self-cleaning experiments are used to systematically study the corrosion resistance,anti-fouling and self-cleaning properties of the film.The consequent is that the corrosion inhibition efficiency of the composite film reached 98.76%,it also can maintain self-cleaning performance in a variety of complex environments,and corrosion points appeared in the salt spray test 16 days.Computational chemistry shows that LA is used as an intermediate layer to connect the aluminum alloy and r GO.And r GO is adsorbed on the outermost layer.In order to further improve the corrosion protection performance of the film,a HEDP/LA/r GO composite film is prepared on the surface of aluminum alloy by r GO LA and 1-Hydroxy Ethylidene-1,1-Diphosphonic Acid in this paper.SEM,EDS,XPS,FT-IT and Raman test techniques are used to characterize the morphology and composition of the film.Electrochemical tests,contact angle tests,salt spray tests and self-cleaning experiments are used to systematically study the corrosion resistance,anti-fouling and self-cleaning properties of the film.The results showed that the corrosion inhibition efficiency of the composite film reached 99.96%,and corrosion points appeared in the salt spray test 28 days.Computational chemistry shows that the phosphate group in HEDP is the main active site,it acts as an intercalation layer between the aluminum alloy and the electrodeposited layer in the way of-P-O chemical bond.