ZnMn alloys obtained using pulse, reverse and superimposed current modulations

Zinc-manganese alloys were electrodeposited using pulse techniques: pulse, pulse reverse and superimposed pulse. The alloys obtained under each condition were characterized by their composition, thickness, morphology and structure. Results indicate that, in the same interval of average current densities, all methods led to similar or higher manganese contents than those obtained using direct current (dc), but current efficiencies were lower. In general, all pulse methods improved the thickness and composition uniformity of the alloys, particularly, when pulse reverse plating was used. However, current efficiencies with this method were so low that the process would be uneconomical. With pulse and superimposed pulse techniques uniform and compact alloys were obtained, the latter method with current efficiencies that were slightly higher than the former. Moreover, the structure of the alloys obtained with the pulse techniques was simpler than that observed with dc plating and monophasic alloys could be obtained in a wide interval of conditions.