Structural factor in Zn alloy electrodeposit corrosion

AFM, XRD, XPS analyses were performed to characterize Zn, Zn–Co, Zn–Fe and Zn–Ni electrodeposit topography, texture, lattice imperfections, as well superficial corrosion product film composition and properties. The difference in the coatings’ corrosion resistance manifested when a passivating oxide film formed on the metal surface. Higher values of diffraction line integral breadth for Zn–Co and Zn–Ni alloys were detected, which implied a greater number of lattice imperfections for the samples. Besides, a higher surface activity for oxide film formation for the same surfaces was observed. It was suggested that the metal structural parameters lattice imperfection and texture.were responsible for the oxide films’ properties, which determined the coatings’ corrosion resistance. An amorphous structure and a higher amount of hydrated Zn oxide in the corrosion product film reduced Zn–Co and Zn–Ni corrosion rates when compared to that of Zn and Zn–Fe. q1999 Elsevier Science B.V. All rights reserved