Abstract
A sulfate bath was used to investigate the influence of current density on the electrodeposition behavior of Zn-Ni-Mn on steel. The presence of Zn2+ in the plating bath during Zn-Ni-Mn alloys codeposition is the cause of significant inhibition of Ni and Mn deposition. A transition current density was noticed above where in a transition from normal to anomalous deposition took place. At a higher current density, a uniform surface deposit of Zn-Ni-Mn was obtained. At lowest current densities, The deposits showed higher corrosion resistance because of normal deposition and for the highest studied current densities attributed to the thickness and the surface morphology. Cyclic voltammetry and galvanostatic techniques for electrodeposition were utilized in the investigation while linear polarization resistance and anodic linear sweeping voltammetry techniques were used for the corrosion study. The results revealed that the increase in current density favors the increase of Ni and Mn contents in the deposits. Zn-Ni-Mn alloys with higher Ni content showed higher resistance to corrosion and higher cathodic current efficiency.