  Silver (Ag) coatings have been widely used in many industry areas due to
their excellent conductivity. However, wider applications of Ag coatings have
been hindered by their poor mechanical properties. In this research, to improve
the mechanical performance, Ag-Bi nano-composite coatings were prepared by a
novel ionic co-discharge method. A systematic study of the microstructure,
mechanical properties, electrical conductivity and antibacterial behavior of
the resulting coating was performed. The results indicated that after adding an
appropriate amount of Bi containing solution into the Ag plating solution,
Ag-Bi nano-particles were in-situ formed and distributed uniformly throughout
the coating matrix, resulting in a significant improvement in the mechanical
properties. The hardness of Ag-Bi coating was increased by 60% compared to that
of the pure Ag coating. The corrosion resistance of Ag-Bi coatings was also
enhanced. The outcome of this research may find a broader application in
electronics, jewelry, aerospace and other industries.
