Papers by Author: Xu Hui Zhao

Abstract: EIS is used in this paper to study the effects of anodic oxidation parameters on the film’s ability, and multi-layer equivalent circuits are proposed. The oxidation time has great effect on porous layer, the porous layer’s impedance increases as the anodic oxidation time prolong; anodic current density has effect on both barrier layer and porous layer, higher current density gets higher impedance values in both barrier layer and porous layer; anodic oxidation temperature has great effect on barrier layer, when the temperature decreases, the barrier layer’s impedance increases.

Abstract: The electrochemical behaviors of anodized and sealed aluminum alloys in NaCl solution were studied by potentiodynamic polarization, the open-circuit-potential and EIS. The results show that anodic oxidization of aluminum increases its corrosion resistance greatly. Different sealing methods have different influences on corrosion behavior of the anodized alloys in NaCl solution; corrosion resistance increases in the order: no sealing < water sealing < dichromate sealing < nickel fluoride sealing. The modulus of the porous film sealed by dichromate solution increases with the immersion time in NaCl solution, which is similar to the self-sealing effect of unsealed anodic films.

Abstract: Formation of clusters with high corrosion resistance on anodic films of Aluminum by Ni ions implantation was studied. Ni ions were implanted in anodic films of 1070 aluminum at an energy of 40 keV with dose of 5.0×1017 ions/cm2. XPS analysis reveals that Ni is present in the states of metallic Ni and NiO on the surface of the anodic film. Electrochemical results show that anodic films with Ni ions implantation provide relatively higher corrosion resistance in NaCl solution. The anti-corrosion clusters on the surface of anodic films should be the main reason for better corrosion resistance of the implanted samples.