Nature of contact corrosion layers on lead alloys: A study by impedance spectroscopy

Corrosion layers on lead, lead-antimony and lead-calcium alloys doped with various components (Cd, Sn, Ba, and Ag) were studied using impedance spectroscopy. The films were formed under different potentials and polarization conditions in 4.8 M sulfuric acid solution. The nature of the corrosion layer formed at the alloy-oxidation products interphase was studied using impedance spectroscopy. The results show that the processes proceeding at this boundary can be simulated with an equivalent circuit corresponding to a two-layer model of the corrosion film (an outer high-conducting part and an inner low-conducting one). Parameters of the proposed equivalent circuits were estimated. (C) 2011 Elsevier B.V. All rights reserved.