Electrochemical corrosion behaviour and surface morphology of electrodeposited zinc, zinc–cobalt and their composite coatings

The electrochemical behaviour as well as the surface morphology characteristics of electrodeposited Zn and Zn-Co (≈3 wt-%) alloy coatings on low carbon steel samples, with and without included nanoparticles of organic co-polymers in their structure, are discussed. Their corrosion resistance and protective properties were studied in a model corrosion medium, 5 wt-% NaCl, using electrochemical methods such as polarisation resistance (R p) measurements and potentiodynamic (PD) polarisation curves. Scanning electron microscopy (SEM) was performed to examine the surface morphology changes of the samples before and after the corrosion treatment. Some conclusions are drawn about the influence and importance of the organic nanoparticles on the corrosion behaviour of the coatings presented.