Electroplating of Co-W and Co-Mo Alloys from Na2WO4 Ionic Melts

The cathodic reduction processes of cobalt (II), tungsten (VI) and molybdenum (VI) in Na2WO4 melts are discussed. Electrochemical behavior of cobalt in a tungstate melt, as well as the effect of electrolysis conditions on the composition and structure of Co-W and Co-Mo alloys deposits from tungstate-molybdate melts is also studied. With a decrease in the concentration of cobalt ions and an increase in the concentration of molybdenum (tungsten) ions in the melt, the phase composition of cathodic deposits is shown to change from individual cobalt to individual molybdenum (tungsten) via a series of cobalt-molybdenum (tungsten) compounds of various compositions.