Preparation and Research on Corrosion Resistance of Hydrophobic Surface on 7050 Aluminum Alloy

The hydrophobicity of 7050 aluminum alloy has a vital influence on its corrosion resistance. In this study, the micro/nano rough structure of 7050 aluminum alloy surface is prepared by chemical etching method, and then the surface is soaked in stearic acid ethanol aqueous solution for hydrophobic treatment. The microstructure and wettability of the hydrophobic surface are analyzed and studied by contact angle, scanning electron microscope (SEM) and other testing methods, the corrosion resistance tested and analyzed by electrochemical workstation, and the corrosion mechanism investigated. Results show that uniform surface with excellent hydrophobicity can be obtained when the 7050 aluminum alloy is etched by hydrochloric acid for 10 min, and soaked in 0.06 mol/L stearic acid ethanol aqueous solution for 12 hours. Compared with those of the blank matrix material, the self-corrosion current density of 7050 aluminum alloy with hydrophobic surface decreases, i self-corrosion voltage increases, and the radius of the impedance arc increases. Therefore, the corrosion resistance of the sample is improved. The corrosion forms of 7050 aluminum alloy with hydrophobic surface are pitting corrosion and intergranular corrosion. This research provides a practical solution for the preparation of hydrophobic surface on 7050 aluminum alloy with good corrosion resistance.v