Effects of mechanical and chemical pre-treatments on the morphology and composition of surfaces of aluminium alloys 7075-T6 and 2024-T3

The effects of mechanical and chemical pre-treatments of AA7075-T6 and AA2024-T3 aluminium alloys were studied in terms of changes of morphology, composition and wettability of the surface, and of the related corrosion properties in sodium chloride solution. The mechanical treatments tested include grinding under water and polishing under non-aqueous liquid. The latter preserved the content of Mg at the AA7075-T6 surface. The effect of mechanical treatment was less pronounced on AA2024-T3. The chemical treatments included etching with sodium hydroxide and with a commercial cleaner and desmutting in nitric acid. The sample pre-treatment affects the polarization curves in sodium chloride. (C) 2017 Elsevier Ltd. All rights reserved.