Structure and wettability of pulsed electrodeposited Ni-W-Cu-(α-alumina) nanocomposite

The Ni-W-Cu-(alpha-alumina) nanocomposite layers were formed on carbon-steel substrate using pulse current electrodeposition. The effects of pulse frequency and duty cycle on structural characteristics and wettability of coatings were investigated. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were employed to study the microstructure and chemical compositions, respectively. Structural analysis was also carried out using the X-ray diffraction (XRD) method. To investigate wettability features, contact angle measurements were performed. Results revealed that pulse plating parameters could significantly influence the structure, composition, morphology, and wettability of nanocomposite coatings. The atomic force microscopy (AFM) and profilometry results showed that coatings with rough surfaces are obtained at lower pulse frequency. The EDS analysis indicated that the lower duty cycle results in deposition of more amounts of copper and alumina. The larger hydrophobic surfaces can be obtained at higher duty cycles, where the lower duty cycles lead to fabrication of hydrophilic surfaces. (C) 2016 Elsevier B.V. All rights reserved.