Abstract
Direct, pulsed or periodically reversed current was applied to the electrodeposition of Ag-Zn alloys from cyanide baths. In the direct current plating, the electrodeposition behavior of each metal showed the regular type composition in which the deposition of less noble Zn proceed only in the limiting current region of noble Ag. In the pulsed or periodically reversed current plating the reasonable explanation of the trends of change in alloy composition was made by mainly considering the recovery of Ag concentration in the vicinity of the cathode on the basis of above deposition mechanism. In these periodical electrodeposition, the composition of alloys was determined by the average cathodic current density, and it was estimated that the replacement reaction of deposited Zn with Ag ions occurred at the off-time of pulsed current plating and the same amount of deposited Ag and Zn dissolved in the anodic current pulse period of periodically reversed current plating. Further, the effect of pulsed or periodically reversed current on the surface appearance of the alloys was discussed.
