Applied Surface Science, Vol.254, No.6, 1644-1650, 2008
Surface characterization of the Zn-Ni-Al2O3 nanocomposite coating fabricated under ultrasound condition
Zn-Ni-Al2O3 nanocomposite coating, which was fabricated by eletrodeposition technique with the aid of ultrasound, was investigated by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis and X-ray photoelectron spectroscopy (XPS). The results reveal that 7.2 wt.% nano-alumina particles uniformly dispersed in the matrix of the composite coating. The XPS analyses demonstrate that the outermost layer of Zn-Ni-Al2O3 coating was composed of nano-alumina and Zn(OH)(2), while the transition layer between the outermost layer and the Zn-Ni matrix consisted of nano-alumina, metallic Zn, ZnO and metallic Ni. In order to investigate the influences of ultrasonic agitation and the incorporation of nano-alumina on the composition and surface structure of Zn-Ni matrix, the comparison studies of Zn-Ni-Al2O3 nanocomposite coating with Zn-Ni coatings fabricated with and without ultrasound were conducted. The results indicate that ultrasonic agitation resulted in a decrease of Ni content in the Zn-Ni matrix and an increase of the thickness of surface oxide layer; while the incorporation of nano-alpha-Al2O3 increased the Ni content in the Zn-Ni matrix. (c) 2007 Elsevier B.V. All rights reserved.