Effects of pH Value of the Electrolyte and Glycine Additive on Formation and Properties of Electrodeposited Zn-Fe Coatings

This study investigates the influence of pH value of the electrolyte and the presence of glycine on the formation and properties of electrodeposited zinc-iron (Zn-Fe) coatings. The primary objective was to evaluate the uniformity and corrosion protection performance of these coatings when applied in an environmentally friendly and cyanide-free sulfate bath under continuous current. Electrochemical tests were conducted in a 3.5% NaCl solution, examining both the presence and absence of glycine as an additive. The method encompassed the use of scanning electron microscopy (SEM) for deposit morphology analysis and X-ray diffraction (XRD) for assessing crystallographic orientations. The findings revealed that the quality and corrosion resistance of the Zn-Fe coatings were significantly affected by the pH of the electrolyte, showcasing improved properties with a higher pH value, whereas a pH of 5 led to diminished uniformity and corrosion resistance. Furthermore, the presence of glycine in the plating bath was found to decrease the corrosion resistance of the coatings, indicating its complex role in the electroplating process. This research contributes valuable insights into optimizing Zn-Fe coating formulations for industrial applications, particularly in the automotive sector.