Mechanical attrition enhanced Ni electroplating

Abstract

Ni coating was deposited on carbon steel by a mechanical attrition enhanced electroplating (MAEE) process. The electroplating was conducted in a traditional Watts' solution and the mechanical attrition action was applied by impact of glass balls on the sample surface with a special vibrating frequency. It is shown that the attrition has significant effects on the microstructure and the characteristics of electroplated Ni coating. When the current density is below a limited current density ( i L), the growth of grains is hindered under the mechanical attrition action and the nucleation of Ni grains processes at a high rate. Thus the Ni coating deposited has smooth surface morphology, refined grain size, pore-free, and with increased microhardness and excellent corrosion resistance. When the current density is above i L, Ni dendrites formed by conventional electroplating can be cold-welded together by the moving glass balls, resulting in a compact Ni coating. Therefore, high-dense Ni coatings can be plated at a high current density and deposition rate.