Abstract:

A trace amount of one rare earth metal cation, e.g. Ce3+ was added to the activation solutions to enhance the electroless plating of Ag on Cu powder. Polarization curves of activation solutions, micromorphology and the clad ratio of silver on copper powder surface were studied through electrochemistry and scanning electron microscopy. The results show that the Ce3+ added to the Pd2+ activation solutions with an appropriate amount enables the decrease of polarizability, the increase of static potential and plating potential. Therefore, the reaction of activation solution became easier. A suitable amount of rare earth element can increase the deposition speed of silver on copper powder surface. With the further increase of rare earth element content, the particle size of silver plating on copper powder tend to dcrease and the coatings became clease gradually. The optimal addition value of Ce3+ is 0.32 g/L.

Key words: Rare Earth, Silver-Coated Copper Powder, Activation