Experimental Investigation and Time Effect on the Anticorrosion and Microstructural Properties of Zinc Flake Nickel−Phosphorus Coating Electrodeposited on Mild Steel

Abstract

In this work, the potential of ZnSO4·7H2O in NiP sulphate electrolyte deposited on mild steel under constant optimum pH of 5, current density of 1 A/cm2, stirring rate of 200 rpm, and varying time parameter between 10, 15, 20, and 25 min were studied using the electrodeposition method. The microstructure properties and corrosion resistance characteristics were analyzed using a scanning electron microscope enhanced with an energy-dispersive spectroscope and potentiodynamic polarization apparatus, respectively. The codeposited was subjected to different media test rig of 0.5 M H2SO4 and 3.5% NaCl to examine the susceptibility effect. The results pointed out that there is a stable mass weight gain as the time increases, which facilitates the formation of dispersed crystal build-up and homogeneous NiPZn content within the interface. A remarkable corrosion property was also noticed with deposits of highest time effect, which is invariably a factor of solid bonding seen at the surface lattice.