Investigation on the Functionally Graded Properties of Zn–6MgO–12MnO2 Composite Coating Fabricated by Dual Anode Electrolytic Deposition Technique

The effect of MnO 2 particulates on Zn–MgO composite prepared via electrocodeposition route on low carbon steel was investigated. The experiment was conducted at constant current density of 11.2 A cm −2 . The microstructural properties of the coated surfaces were characterized using high-resolution Nikon Optical Microscope (OPM) and scanning electron microscopy attached with energy-dispersive spectrometer (SEM/EDX). The corrosion behaviour was examined using linear polarization method in 3.5% NaCl-simulated seawater environment. The micro-hardness features of the electrodeposits were analyzed by dura scan hardness tester. The homogenizing and thermal stability of the fabricated composite was determined at 200 °C for 4 h. The results show that the structural performance and corrosion resistance property of the coating is dependent on the dispersion strengthening of the particle incorporation. The micro-hardness of the deposited samples increased with the increased addition of MnO 2 with over 90%. The improvement in the micro-hardness of the deposited samples suggests that MnO 2 has a strengthening effect on the mild steel.