Optimization of the morphology, structure and properties of high iron content Zn–Fe coatings by pulse electrodeposition

An additive-free gluconate based alkaline electrolyte was used to study the electrodeposition of Zn and Zn–Fe coatings. Cyclic voltammetry performed define accurate deposition parameters identify reactions taking place. Electrodeposition using direct pulse currents. Electrodeposits were characterized in terms morphology, microstructure, mechanical corrosion properties. Homogeneous 7 wt% Fe obtained, composed hexagonal blunted pyramidal grains respectively. Pulse current carried out improve morphology reduce impact hydrogen evolution reaction. Deposition such as on-time/off-time/peak density (ton/toff/jp) investigated. The average jm seems control composition electrodeposits. High iron contents obtained at low densities content abruptly decreased when increased for both currents electrodeposition. Incorporation led an increase micro-hardness coating. Scratch tests order evaluate damage coatings, coating adhesion could be assessed. Polarization curves 3.5 NaCl after 1 h immersion open circuit potential did not show any change between deposits. This shifted a more positive value 14 Fe, which points this best choice galvanic steel substrate deposit. These results linked microstructure deposits perhaps presence ?1-Fe5Zn21 phase Fe.