The Assessment of Mechanical and Corrosion Characteristics of Electrodeposited Cu-Ni-W Thin Films

The process of electrodeposition of Cu-Ni-W thin films is discussed in the article, utilizing an aqueous sulfate–citrate bath. The current density was varied within the range of − 5 to − 60 mA/cm². The high-resolution field emission scanning electron microscopy analysis illustrated that the films possess a uniform, dense microstructure and a metallic luster. Upon inspection of the cross-sectional micrograph, it was determined that the film thickness ranges from 1 to 1.2 µm. Additionally, the energy-dispersive spectroscopy findings disclosed that the films were rich in copper, with copper content ranging from 59 to 92 wt.%. Tungsten content was found to vary between 1 and 36 wt.%, and nickel content ranged from 4.6 to 11.6 wt.%. The atomic force microscopy confirmed that films were quite smooth with the minimum average roughness of 1.7 nm for the film deposited at a current density of − 5 mA/cm². X-ray photoelectron spectroscopy analysis has verified the existence of metallic Cu, Ni, W, and their oxidized states on the external layer of the films. The maximum hardness of 2 GPa and elastic modulus of 74 GPa were obtained from the nanoindentation tests. It was found by Tafel polarization that film deposited at a current density of − 5 mA/cm² exhibited the corrosion resistance of 8626 Ω-cm² when compared to films deposited at higher current densities. The greater charge transfer resistance of 7112 Ω cm² obtained by the electrochemical impedance spectroscopy also indicated the corrosion resistance characteristics of these deposits.