The fabrication, characterization and electrochemical corrosion behavior of Zn-TiO2 composite coatings

Abstract

Metal-nanoparticle composite coatings improve the hardness, wear resistance and corrosion resistance properties of metal coatings. In this work, TiO <inf>2</inf> nanoparticles were chosen as second-phase particles to generate anticorrosive Zn composite coatings. The TiO<inf>2</inf> nanoparticles were dispersed in a Zn plating solution to co-deposit them with Zn. The Zn-TiO <inf>2</inf> composite coatings were then characterized by scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDS) and x-ray diffraction methods. The presence of TiO<inf>2</inf> particles in the composite was confirmed by SEM images and EDS spectra. The Zn-TiO<inf>2</inf> composite coatings incorporated with different amounts of TiO<inf>2</inf> particles were tested for corrosion performance by polarization and electrochemical impedance spectroscopy, and the dissolution behavior of the coatings that had been immersed in corrosive media for a long time was studied. Improved corrosion resistance properties of the Zn-TiO<inf>2</inf> composite coatings were confirmed by polarization studies, fitted Nyquist plots, an increase in phase angle and a shift in the R<inf>ct</inf> characteristic peak of the Bode plot. © 2011 The Royal Swedish Academy of Sciences.