Selective dissolution during acid pickling of aluminum alloys by element-resolved electrochemistry
By Sultan, B. Bin Mohamad; Thierry, D.; Torrescano-Alvarez, J. M.; Ogle, K.
Published in Electrochimica Acta
2022
Abstract
The surface reactivity and the elemental dissolution of a high-strength aerospace alloy (AA7449-T651) during acid pickling was investigated with element-resolved electrochemistry (AESEC). The results demonstrated a sequential dissolution of Mg, Al, Zn and Cu, following the order of their respective galvanic reactivity in common acid pickling solutions. The enrichment of Cu during pickling with the H2SO4 solution was observed. The effect of oxidizing solution components HNO3 and Fe(III) on Cu dissolution were investigated using an experimental Evans diagram approach.