Initiation of copper dissolution in sodium chloride electrolytes

• Published in: Electrochimica acta 2006-08, Vol.51 (26), p.5660-5668
• Main Authors: Starosvetsky, D., Khaselev, O., Auinat, M., Ein-Eli, Y.
• Format: Article
• Language: English
• Subjects: Applied sciences; Chlorides; Copper activation; Corrosion; Corrosion mechanisms; Exact sciences and technology; Incubation period; Localized corrosion; Metals. Metallurgy; Passivity breakdown
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2006.01.058

Initial stages of copper activation in chloride-ion containing neutral aqueous solution were studied. The results point that activation of copper passivity is initiated once the potential exceeds the breakdown value, occurring with well-defined incubation period, similar to that of other passive metals in chloride environments. The effect of applied potential and Cl − ion concentration on the incubation period is presented. The results indicate that an incubation period for copper activation in chloride containing solutions can be associated with the formation of a two-dimensional CuCl layer on the metal surface. The incubation period is relatively long at negative potentials and it is decreases with a positive shift in the potential. At a certain potential, the incubation period is sharply decreased. The time-frame of incubation period is attributed to the formation rate of two-dimensional CuCl layer and its reduction rate. The formation of a stable salt film on the metal surface facilitates localized rapid dissolution of the copper.