Effect of current density on the morphology of Cu-Zn coating electrodeposited on St-37 steel in deep eutectic electrolyte

Electrodeposition is an economical method for producing metallic coatings and provides good control on the thickness and morphology of the coatings, especially for alloy coatings. Copper-zinc alloys, due to their superior properties compared to pure metal coatings, have wide applications in the industry. Electrodeposition of alloy coatings is typically performed using aqueous electrolytes, but these solvents pose certain challenges. Deep eutectic solvents, compared to aqueous electrolytes, have higher metal solubility capacities due to their wide electrochemical window and superior electrical, chemical, and thermal stability. In this study, deep eutectic solvents were utilized instead of water. A zinc-copper alloy was deposited on steel from a deep eutectic solvent composed of choline chloride-ethylene glycol with a molar ratio of 1:2. The coating morphology and composition were examined by SEM-EDX. The chemical composition of the coating was obtained 50:50 ratio of Zn:Cu. Using 5 mAcm-2 current density, the coating thickness was obtained 16 micrometers. It can be concluded that copper-zinc alloy coatings can be produced using deep eutectic solvents.