Evaluation of corrosion behaviour of Pb-Co3O4 electrodeposited coating using EIS method.

• Fabricating Pb-Co 3 O 4 coating using pulsed current electrodeposition to achieve higher particle incorporation. • Increasing the corrosion resistance of the Pb-Ca-Sn substrate and DC deposited Pb-Co 3 O 4 coating. • Analyzing the electrochemical behavior of Pb-Co 3 O 4 coating and Pb-Ca-Sn substrate using EIS method. • Studying the effect of CoSO 4 additive on corrosion behavior of the system. • Studying the effect of prolonged polarization and inspecting the system's behavior using EIS method. Pb-Co 3 O 4 composite coating was electrodeposited using direct and pulsed current on Pb-Ca-Sn substrate. Corrosion evaluation using electrochemical impedance spectroscopy (EIS) in copper electrowinning electrolyte revealed that PC deposited coating has higher corrosion resistance than its DC counterpart, due to its higher incorporated particles and increased surface homogeneity. However, it was demonstrated that the presence of CoSO 4 as an additive in the electrolyte is crucial for the coating (irrespective of the deposition method) to maintain its higher electrochemical stability. Moreover, after prolonged polarization, the coating exhibited higher impedance in the subsequent EIS results as compared to that of the substrate. [ABSTRACT FROM AUTHOR]