Synthesis of silver coatings by brush plating with cyanide-free solution

Abstract

Silver coating can be used to improve the surface properties of components made of copper in terms of corrosion resistance, wear resistance and electrical contact conductivity. A cyanide-free solution based on Na₂S₂O₃ is proposed for the brush plating of silver coating on copper substrate. XRD, SEM and microhardness tester were used to characterize the microstructure and properties of the coatings. It is found that this cyanide-free solution can deposit silver coating with high efficiency. Coatings consist of nano-sized grains which present as aggregated nodular morphology. The brush plated coatings show microhardness of 122.47 Hv, which is promising in the engineering application of electrical contact components.