Effect of pH and Temperature on Bright Silver Electroplating by Non-Cyanide Silver Electrolyte

At low pH in the electroplating of silver using a sulfite salts system, the polarization decreased at higher temperatures. Cathodic current efficiency was reduced, and the deposited crystals were larger. At low pH and low temperature, a bright deposited film was obtained. At higher pH and higher temperature, the polarization was reduced slightly, and the change in cathodic current efficiency was reduced slightly. Even at high pH and high temperature, crystals were microcrystalized and films of high brightness were obtained. At all values of pH, the preferred orientation of all the electroplated crystals tended toward (220) with changes in temperature, and this tendency became stronger the higher the pH and temperature.