抄録
Bright silver coatings were obtained from silver-succinimide baths. The pH dependence on the rest potential of Ag electrodes and the cathodic polarization curve were measured to clarify the electrodeposition mechanism. The effects of pH, temperature, and the bath's silver concentration on surface appearance were evaluated using Hull Cell tests. The current efficiency and microscopic surface morphology were also examined.
The bath composition and operating conditions most conductive to obtaining a mirror-bright surface on the electroplated silver were 0.45mol/L of CH3SO3Ag, 1.5mol/L of succinimide, 0.025mol/L of Na2B4O7, a pH of 10, and a 25°C bath temperature. Cathode current efficiency exceeded 90% at current densities between 10 and 20mA/cm2. It was estimated that the silver was deposited from Ag (C4H4O2N)2- complex ion and the process was controlled by the charge transfer in the bath.
