Production of Silver Coated Copper Powders by Electroless Plating Method

Copper powders with very dense, uniform silver coating layer were prepared by electroless plating method in aqueous system at room temperature. Silver-copper composite powders were obtained by strictly controlling the activation and complexing process variables such as NH4OH/(NH4)2SO4 molar ratio, tartrate concentration, and feeding rate of silver ion solution. The mechanism of composite powders formation and their characteristics were discussed. It is noted that completely cleansing the oxide layers and protecting the copper particles surface from hydrolysis are key factors to obtain high quality Ag-Cu composite powders.