Corrosion Protection of Cu Electrical Cable by W-Ni Composite Coatings Doped with TiO2 Nanoparticles: Influence of Pulse Currents

W-Ni-TiO2 nano-composite layers were electrodeposited on copper surface by both direct (DC) and pulse (PC) currents. The copper substrates are samples from the main electrical cable used for the Renault K-Z (the latest 100% electric vehicle). In order to investigate coating morphology, atomic force microscopy was used, while energy-dispersive x-ray analysis was applied to determine nano-composite composition. Based on surface morphology, the W-Ni-TiO2 (DC) alloy surface was covered by massive agglomerates, especially when the W-Ni-TiO2 (PC) nano-composite coating was more compact, thicker and exhibited smaller grain size. The coated surface revealed different contents such as 43.4 and 65.4% of W in DC and PC coatings, respectively, which are considered to be a novel composition of the W-Ni alloy. XRD studies revealed that the NiW2 phase only occurs in the W-Ni-TiO2 (PC) nano-composite alloy. Electrical and thermal conductivities, microhardness and porosity values are enhanced by the addition of TiO2 to the alloy.