Effect of square pulse current densities on anticorrosive behavior of Ni–Zn multilayer deposited coatings on mild steel

This paper reports the production of Ni–Zn multilayer alloy coating to improve the anticorrosive behavior of the mild steel material. The deposition technique follows the square wave current pulse technique. Initially, the effect of current densities on the anticorrosive behavior of the Ni–Zn was investigated. Later, the current densities were optimized in different combinations to get a multilayer of Ni–Zn with different degrees of layering. The Ni–Zn multilayer coatings were developed on the surface of mild steel with different numbers of layers by square pulsing current density of 1 Adm⁻² and 3 Adm⁻². The deposited Ni–Zn alloy coating was studied for its electrochemical behavior toward corrosion. Results revealed that the anticorrosive behavior of the multilayer Ni–Zn alloy coating was found to be many folds higher than that of monolayer Ni–Zn alloy coating. The comparison study of corrosion data revealed that (Ni–Zn)_1/3/300 multilayer coatings are less prone to undergo corrosion among all developed monolayer and multilayer coatings. The corrosion rate of (Ni–Zn)_1/3/300 was found to be less and in the range of 0.37 mm year⁻¹ among all developed coatings.