Electrochemical Bechaviour of Cobalt and Tungsten Oxides in Molten Carbamide

The electrodepositions of tungsten and its alloys has been of considerable interest because of usual properties of the metal and alloys. The electrodepositions of W and Co from water solutions and Na 2 WO 4 -WO 3 -CoO at 1023 K were investigated in more works. The possibility of electrodeposition of W-Co alloys from carbamide melts at 408 K has been examined. When studying the electrochemical behaviour of cobalt and tungsten oxides and its compounds (WO 3 , Li 2 WO 4 , Na 2 WO 4 , K 2 WO 4 ) in molten carbamide, it can be concluded that maximum limiting currents are typical of the system (NH 2 )2CO-Li 2 WO 4 . Cyclic voltammograms showed the potentials of deposition of tungsten and cobalt. Layered Co-W coatings on nickel cathodes have been obtained by the electrolysis of the molten system (NH 2 ) 2 CO-CoO- Li 2 WO 4 at current densities of 5-10 mA/cm 2 . The cathodic products were analyzed by XRD and JEM-2100F SEM. Fig. SEM of the surface morphology of W-Co coating deposited by electrolysis from (NH 2 ) 2 CO-CoO- Li 2 WO 4 melt. Figure 1