Synthesis of Zn-Bi nano-composite coatings by an ionic co-discharge process

This communication reports a novel synthesis technique for Zn-Bi nano-composite coatings by an ionic co-discharge process. Zn²⁺ and Bi³⁺ ions were co-discharged on the surface of the cathode to form Zn and Bi atoms. Zn atoms formed a continuous Zn coating matrix while Bi atoms formed Bi nano-particles (∼50nm) which were uniformly distributed in the coating matrix. This novel process does not use the particle-mixing method in the traditional nano-composite electroplating, therefore avoiding the agglomeration of nano-particles. The Zn-Bi nano-composite coatings exhibited much better corrosion resistance than Zn coatings. We believe that the ionic co-discharge process may open up a new horizon in the synthesis of nano-composite coatings.