Effect of Current Density on Hardness of Low Carbon Steel Electroplated by Copper, Nickel and Copper-Nickel

Abstract

Coating process of metal surface undergoes rapid development, especially in electroplating method. This study aims to investigate effect of current density on hardness of low carbon steel plates electroplated by copper, nickel and copper-nickel. Low carbon steel plate coated with copper, nickel and copper-nickel using electroplating process with current variation (6, 9, 12 A for copper coating), (2.5, 3.5, 5 for nickel coating) and (2.5, 3.5, 5, 6, 9, 12 A for copper-nickel coating). Electroplating time for the three processes is 20 minutes in 5-liter solution at temperature range of 55-60°C. The electroplated steel plates are characterized with micro vickers hardness test. The results of this study indicated that the highest hardness is 290 kg/mm2 for nickel coating at current density of 5 A. Contrary, the lowest hardness is 111 kg/mm2 in copper coating at current density of 12 A, while the hardness for copper-nickel coating is 252 kg/mm2 at current densities of 12 A and 5 A.