Effect of deaeration on the corrosion of pure aluminum and its three alloys in naoh solution at ph=11

Abstract EN

In this work, the corrosion behaviour of pure Al and its three alloys (Al-Cu-Mg, Al- Mg, and Al-Zn-Mg) was studied in aerated and deaerated 1 x 10-3 mol.

dm-3 NaOH solutions to show the role of dissolved oxygen gas and its reduction at cathode.

Also the aim of this study was to obtain the corrosion parameters such as the corrosion potential (Ecorr), corrosion current density (icorr), cathodic and anodic Tafel slopes (b), and polarization resistance (Rp) besides the thermodynamic and kinetic functions were also calculated (Δ G, Δ S, and Δ H) and (Ea and log A) to comparison these values in the presence and absence of the oxygen.

From the general results for this study can be seen that the polarization resistances for pure Al and its alloys were higher in deaerated solutions and the values of (Δ G) were less spontaneous in deaerated solution, also the activation energy (energy barrier) was higher in deaerated solution.