Strategic Development of Ni–Cu–Fe₂O₃ Composite Coatings to Strengthen Mild Steel Against Corrosion

Mild steel is extensively employed in various industries due to its affordability and versatility. However, its susceptibility to corrosion poses a significant challenge. This study explores the efficacy of protecting mild steel by applying coatings composed of highly noble copper and its alloys. In this direction, Ni–Cu alloy and Ni–Cu–Fe₂O₃ coating have been developed from a sulfate citrate bath on mild steel through the electrodeposition method. The alloy and composite coating deposition was done at different current densities 1 A dm⁻², 2 A dm⁻², 3 A dm⁻², and 4 A dm⁻². The copper content of the coating has increased with an increase in current density in both alloy and composite coatings. The deposit with a high Copper content showed lower crystallite size with a lower corrosion rate value at a current density of 3 A dm⁻². The trace addition of Fe₂O₃ into the Ni–Cu alloy matrix has improved the overall corrosion resistance of the mild steel materials as compared to bare Ni–Cu alloy coating.