Plasma electroplating Ni coating on pure copper sheet-the effects of H _2SO _4 concentration on the microstructure and mechanical properties

摘要

Nanocrystalline Ni coatings were fabricated by plasma electroplating on pure copper sheets. The influence of H _2SO _4 concentration of the plating solution on the arc starting voltage and current value was studied. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-Ray diffractometry (XRD) were used to investigate the coating microstructures. The results indicated that the Ni coating prepared in 40-80g/L H _2SO _4 solutions had the grain sizes of 50-70nm. In addition, the maximum values of microharness and coating adhesion were ~280 HV and 80N, respectively. The formation mechanism of Ni coating prepared using different H _2SO _4 concentration was discussed.