The corrosion current density (I_corr), which is a measure of corrosion rate of copper in aqueous media has been studied using potentiodynamic polarization technique. This is aimed at determining the corrosion behaviour of copper in aqueous aggressive environments. Copper specimens cut out from pure cold-rolled polycrystalline copper test sheets and wet-polished with silicon carbide abrasive paper (from grade #150- #1200), degreased in acetone and dried in warm air were used for the study. The polarization result shows that the corrosion current density of Cu was lower in Na₂CO₃ than in the acid solutions (H₂SO₄ and HCl). Cu could more steadily passivate (in a two step process) in the Na₂CO₃ than in the acid solutions. The two step passivation was attributed to the transformation of Cu⁺ into Cu²⁺. The anodic current density value increased in the order: H₂SO₄>HCl>>Na₂CO₃, while the corrosion potential (E_corr) values shifted to more negative (cathodic) potentials. Generally, corrosion rate of Cu metal increased with an increase in the concentration of the electrolyte solutions.

Corrosion, Corrosion Current Density, Corrosion Potential, Copper, Polarization