Influence of nano-scale twins (NT) structure on passive film formed on nickel

X-ray photoelectron spectroscopy (XPS), potential of zero free charge (PZFC) and double-log of current-time techniques were used to study the effect of nano-scale twins (NT) structure on the chemical component of the passive film, the adsorption behavior of chloride ions on the passive film, and the passivation formation process in the solution containing 0.02 M NaCl. The results indicated that the passive film formed on NT coating was more integrated and more compact than those on IE nickel; the content of Ni(OH)₂ was higher and distribution of various components was more homogeneous across the passive films. The negative and smaller value of ΔE (the difference between the corrosion potential and PZFC) was observed for NT specimen, indicating that the adsorption capability of chloride ions on the passive film on NT specimen was markedly attenuated in the solutions. This decreased the susceptibility of NT specimen to pitting corrosion and was consequently responsible for the higher pitting potential.