Preparation of tin-coated copper powders by chemical reduction

Tin-coated copper powder was obtained by electroless tin plating on surface of copper powder through the reduction of tin hydroxide with sodium borohydride. In order to study the coverage situation and microstructure of tin coating on surface of copper powder as well as the effects of high temperature treatment and preparation methods on its structure, a simulation experiment was carried out using copper foil with different roughness of two sides instead of copper powder. Results showed that copper powder was completely coated with uniform and compact tin coating. The tin coating prepared by reduction reaction is more uniform and compact than that prepared by replacement reaction. High temperature treatment can improve the uniformity and compactness of tin coating.