Characterization and Corrosion Analysis of Electrodeposited Nanostructured Zn–Fe Alloy Coatings

Abstract

Eight distinct Zn–Fe alloy films have been galvanostatically electrodeposited with a current density ranging from 1 to 8 A dm−2. The surface morphology, chemical composition, phase structure and microhardness of these coatings were examined using scanning electron microscope coupled with energy dispersive x-ray spectroscopy (SEM-EDX), X-ray diffraction (XRD) and Vickers Microhardness Tester. XRD results suggest the formation of metastable crystal structure in all the electrodeposits and formation of η phase confirms the higher content of Zn in the coatings. To evaluate the corrosion resistance, the developed coatings were immersed in 3.5 wt% NaCl solution followed by the application of potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) tests on each sample. The results indicated the greater impact of the coating characteristics on the corrosion resistance of electrodeposited Zn–Fe alloy.