Electrochemical Evaluation of the Effect of the Addition of Nanoparticles in Chemical Polishing AA6062T5 Alloy

Abstract

The chemical surface preparation process aims to eliminate rolling marks or scratches providing a smoother surface. Eleven solutions for chemical polishing of aluminium alloy AA6062T5 were used aiming to get the best aesthetic condition without losing corrosion resistance. These solutions were combinations of NaOH, NaCl, Na2SO4, and HNO3 and different amount of SiO2 nanoparticles in these solutions. The samples submitted to these solutions were analysed by electrochemical measurements such as: potential monitoring in open circuit and electrochemical impedance spectroscopy using NaCl 0.1 mol L-1 as electrolyte. The sample subjected to treatment with a mixture of all reagents and with the addition of 1000 ppm SiO2, followed by cleaning with nitric acid solution showed the highest corrosion resistance.