An Examination of Electrodeposited Cu–Ni–W Coatings Using Nanoindentation and Electrochemical Techniques

Abstract

The aim of this work is to investigate the underlying mechanisms by which the deposition current density affects the structural, mechanical and electrochemical properties of Cu–Ni–W coatings electrodeposited via direct current method. X-ray diffraction investigation indicated the formation of face-centered cubic structure with the presence of nickel–tungsten phases. Microstructural analysis revealed that coatings were uniform and compact structure without any obvious defects. Cu–Ni–W thin films were thoroughly evaluated for their mechanical, structural, and corrosion resistance properties. Nanoindentation tests were carried out to calculate the mechanical properties, which include stiffness, elastic modulus, and nanohardness. The elastic modulus of 102 GPa and the hardness value of 5.4 GPa were obtained for the film deposited at –50 mA/cm². Examination of the electrochemical Tafel plots indicated that the films deposited at higher current densities exhibited improved resistance to corrosion. The variation of I_corr values from 2.12 to 1.86 µA/cm² implied that these films have a lower susceptibility to corrosion.