Influence of selenium-containing additives on the electrodeposition of zinc-manganese alloys

In the present paper we report on the influence of some selenium-containing additives on the electrodeposition of zinc-manganese alloys. Selenous acid (0.05-0.20 g/L) and ammonium selenate (0.5-2.0 g/L) were added to sulfate- citrate baths. Investigations of alloy composition were carried out by atom ic absorption spectrometry and EDX. The morphology of the coatings was stud ied by SEM and the crystal structure of the as-plated and corroded samples were investigated by XRD. The effects of deposition time on quality and com position of alloy were highlighted. Corrosion behavior of Zn-Mn alloys with and without traces of selenium was investigated by measurement of free cor rosion potentials in aerated sodium chloride solution.