Corrosion Characterization of Zn-Mn Hybrid Coatings with Surface Conversion Layers

What awaits you in this article: Hybrid Zn-Mn(11 wt.%) alloy coatings containing in their matrix stabilized polymeric micelles (SPM) are electrodeposited from a sulfate bath. SPM are added to the electrolytic bath in concentrations of 0.1 or 0.3 wt.%, respectively. The coatings are additionally treated in Cr(III)-based solutions for obtaining of surface conversion layers (CL) aiming at receiving of better corrosion resistance. Surface morphology of the hybrid coatings (with or without additional conversion layer) is presented by SEM. The protective characteristics are evaluated with potentiodynamic polarization (PD) and polarization resistance (Rp) measurements in a model corrosion medium of 3% NaCl solution. Experimental results demonstrate the better corrosion resistance and the greater protective ability of the hybrid coatings obtained from electrolyte with 0.1 wt.% SPM, compared to the ordinary Zn-Mn alloy.