Electrodeposition of nanocrystalline Ni-Cu alloy from environmentally friendly lactate bath

A new environmentally friendly electroplating bath for Ni-Cu alloy deposition was developed. Lactic acid was used as a complexing agent. The influence of bath composition, current density, pH and temperature on cathodic polarization, cathodic current efficiency and alloy composition was studied. Different proportions of the two metals were obtained by using different deposition parameters, but at all [Ni2+] / [Cu2+] ratios studied, preferential deposition of Cu occurred and regular co-deposition took place. The Ni content of the deposit increased with Ni2+ content and current density and decreased with temperature. The surface morphology of the deposited Ni-Cu alloy was investigated using scanning electron microscopy. The crystal structure was examined using the X-ray diffraction technique. The results showed that the deposits consisted of a single solid solution phase with a face-centered cubic structure. The crystallite size lies in the range of 12 to 25nm for as-plated alloys. Copyright (c) 2014 John Wiley & Sons, Ltd.