Manganese electrodeposition from urea-rich electrolyte

Abstract

Pure manganese coatings were prepared on the steel (AISI 4340) electrode by a non-conventional electrodeposition method, in the presence of 8 mol dm-3 of urea as a plating additive. The influence of urea on the electrodeposition of Mn was investigated by cyclic voltammetry. The morphology of the coat-ings was studied by scanning electron microscopy (SEM), and their elemental composition by energy dispersive X-ray spectrometry (EDS). The results showed that the presence of urea in the solution in-creased the current efficiency for metal reduction for around 20%, and depending on the applied deposi-tion potential, urea may act either as a complexing agent or through the adsorption mechanism. Moreover, urea improves the characteristics of Mn deposits, i.e. their adhesiveness, porosity, compactness, and ap-pearance. Except for oxygen, as part of the Mn corrosion product at the coating surface, no carbon or ni-trogen incorporation was detected in the deposits by EDS.