Electrochemical analysis of an electrodeposited Zn-Ni alloy films contained EDTA stable baths in 3.5 wt% NaCl solutions

The electrochemical analysis of an electrodeposited Zn-Ni alloy coating on steel substrate from a chloride bath containing ethylene-diamine-tetra-acetic acid (EDTA) was investigated in this study. Polarization tests demonstrated that the Zn-Ni alloy deposited from 0.119 M EDTA bath at 20 mA/cm(2) current density exhibited lower corrosion current (I-corr) and more positive corrosion potential (E-corr). The impedance modulus and corrosion resistance were improved with a fine and robust uniform coating. At 24 h of immersion time, the samples exhibit higher corrosion resistance leads to the formation of strong corrosion product layers. The morphological properties, crystalline phases, and topographical structures of ZnNi coatings were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and atomic force microscopy (AFM). The chemical composition analysis revealed that the Zn-Ni coatings deposited from EDTA baths have higher Zn content and intensity of Ni2Zn11 gamma-phase, which exhibited better corrosion resistance properties. (C) 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the 2nd International Conference on Recent Advances in Materials & Manufacturing Technologies.