Electrodeposition and corrosion behaviour of copper-nickel alloys

The mechanism of copper–nickel electrodeposition from citrate solutions on steel substrates has been investigated by cyclic voltammetry and potentiostatic polarisation to determine the influence of the Cu/Ni ratio. The presence of nickel cations makes copper deposition easier by decreasing the nucleation potential of both copper and nickel. Coatings obtained from three solutions with different Cu/Ni ratios were analysed by scanning electron microscopy and energy dispersive X-ray spectrometry to observe the morphology and the copper and nickel contents in the deposit. The structure was analysed by grazing angle X-ray diffraction and the corrosion resistance was studied by impedance measurements.