The Research Of Preparation And Corrosion Resistance Of Superhydrophobic Aluminum Surface

The problem of metal corrosion not only causes great loss to the national economy,but also causes a variety of energy and resource waste.Compared with the traditional method of anti-corrosion,superhydrophobic surface treatment technology is a new anti-corrosion and environmentally friendly technology.It can effectively inhibit the corrosion of various functional materials and has great value in a variety of areas.In this paper,superhydrophobic surface treatment is applied to the corrosion and protection field,and the superhydrophobic aluminum alloy surface is prepared by different methods.The corrosion resistance of aluminum alloy in simulated seawater is studied.In this paper,different superhydrophobic films with different micro-nano structures are fabricated on aluminum alloy 5052 by different surface treatment techniques.The wettability and the corrosion resistance in simulated seawater are studied by electrochemical test and contact angle measurement.In addition,the surface morphology and composition of the superhydrophobic films are characterized,and the formation mechanism of the superhydrophobic films are also analyzed.The main results are as follows:First,a superhydrophobic film was successfully prepared on the surface of aluminum alloy by one step electrodeposition method.The superhydrophobic surface with the contact angle of 156 o was successfully prepared at a voltage of 10 V.While the electrodeposition solution was 0.04 M cerium chloride heptahydrate and 0.1 M of myristic acid dissolved in ethanol.The method was simple and easy to operate.The results showed that the corrosion efficiency in simulated seawater solution was 99.1%,and the contact angle after 9 days immersion was 143 o,and the inhibition efficiency was reduced to 94.7%.After 60 days exposed in air,the contact angle did not change significantly,still above 150 o.The results showed that the superhydrophobic surface prepared by this method had good stability in air and simulated seawater.Based on EDS elemental and FTIR analysis,the cerium myristate was formed on the surface of the metal after electrodeposition,which had a good superhydrophobicity.Second,using the surface treatment technology of alkaline aqueous ammonia etching and stearic acid modification,the compound micro-nano structure was constructed on the surface of aluminum alloy.The optimum technological conditions are as follows: the mass fraction of aqueous solution is 10 wt.%,the etching time is 6 h,and then modified with stearic acid for 1 h at 60 oC.The contact angle of the prepared superhydrophobic membrane can be up to 153 o,and the surface of the superhydrophobic film is found to have sheet structures.The corrosion resistance of the samples was simulated by the electrochemical method.The corrosion inhibition rate in simulated seawater solution was 99.6%,and the inhibition efficiency fell to 92.9% after immersing for 9 days,which still has good corrosion resistance compared with the bare alumunium.Based on FTIR analysis of superhydrophobic surface and stearic acid,it was concluded that stearate aluminum was obtained on the surface of superhydrophobic aluminum alloy.Third,the samples were hydrothermally heated for 6 h at a temperature of 120 oC in a solution mixture of 0.025 mol / L CeCl3·7H2O and 0.25 mol / L urea,and finally removed in a 60 oC water bath modified with stearic acid for 1 h,superhydrophobic films with micro-nano cerium oxide nanorods were successfully prepared on the surface of aluminum alloy.The contact angle can reach 155.5o,and the corrosion resistance can reach 99.6% in the simulated seawater solution.The inhibition efficiency can reach 97.1% after immersing in simulated seawater for 9 days.Based on EDS elemental and FTIR analysis,it was proved that the cerium oxide nanorod structure was formed after hydrothermal procedure.Furtherly modified by stearic acid,a superhydrophobic surface was obtained successfully.