Electrodeposition and characterization of Cu-Nb composite coatings

Copper coatings containing well-distributed Nb particles were obtained by co-electrodeposition in an acidic sulfate bath. Nb particle concentration in the bath was the most significant factor for the incorporation of Nb particles in copper, followed by stirring rate, whereas current density presented low significance. High Nb particle concentration and low stirring rate led to a higher incorporated Nb particle content. The microhardness of the composite layers was higher than that of pure copper deposits obtained under the same conditions due to copper matrix grain refinement and increased with the increase of both current density and incorporated Nb particle volume fraction. The corrosion resistance of Cu-Nb composites in 0.5 wt.% H2SO4 solution at room temperature was higher than that of pure copper and increased with the increase of the Nb content.