Copper redeposition and surface enrichment during the dissolution of Al‐Cu alloys in different concentrations of NaCl solution. Part 1 – electrochemical measurements

The paper aims to study the dissolution of Al, Al‐3.84%Cu, Al‐5.22%Cu and Al‐11%Cu alloys in different concentrations of NaCl (10‐5‐10‐1 M).

The approach is to use open circuit potential (OCP) and potentiostatic polarization measurements.

Results obtained showed that, as the Cu content was increased in the Al‐Cu alloys, a steady state potential was rapidly reached. Addition of different concentrations of CuCl₂ to 0.5 M NaCl demonstrated that by increasing the concentration of CuCl₂ up to 2 ppm a greater increase in the OCP towards more anodic value occurred from the moment of immersion. Further increases in the concentration of CuCl₂, up to 600 ppm, exhibited the same behavior.

The results of the study reveal that cathodic current was controlled by the oxygen in solution, while the anodic current increased with increased Cu content in the alloy.