In the present work, we studied the effect of critical electrogalvanizing parameters on the quality ofelectrodeposited Zn films. The current density, electrodeposition time, and ZnCl2 concentration ofelectrolyte were optimized to maximize current efficiency and brightness, and also, to minimize thesurface roughness. Importantly, regression models of the response variables were developed. Thesemodels could help industrial applications by providing definitive process conditions to obtain Zncoatings at a desired thickness, roughness and brightness with a high current efficiency. First,preliminary studies were conducted to determine the initial levels of the designated factors. Then, theoptimization was conducted through the Central Composite Design by Design-Expert (trial version).Upon completion of the optimization, analysis of variance was also performed. The optimum values ofcurrent density, coating duration and ZnCl2 concentration were determined as 3.7 A/dm2, 4.4 minutes,and 50 g/L, respectively, at a thickness of 6 mm. Finally, a set of Zn films were deposited at this optimumconditions. The characterization of these films showed that the experimental results were in goodaccordance with model predictions, providing a bright (L*=83.69) and smooth (Ra=0.75 μm) coatingwith excellent adhesion to steel substrate (pull-off strength > 29.4 MPa) at a current efficiency of 98.7%.
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