Abstract

In order to effectively improve the corrosion resistance of aluminum alloys, anodic oxidation technique was used to generate the oxide film. Sealing after anodization is an important step to improve the corrosion resistance of aluminum alloys. In this paper, sealing effect of NaAlO2 solution on the oxalic acid anodized aluminum alloy was studied by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), scanning electron microscope (SEM), and X‐ray photoelectron spectroscopy (XPS). Experimental results show that unsealed anodized aluminum alloys display a porous structure and have poor corrosion resistance but the pores are filled and the corrosion resistance of the sample is significantly improved when anodized aluminum alloy was immersed in 0.2 m/L NaAlO2 solution with pH of 7 for 5 min at 85 °C. Moreover, the anodized aluminum alloy with NaAlO2 sealing exhibited better corrosion resistance compared to the hydrothermally sealed sample, because of the formation of more AlOOH in NaAlO2 sealing treatment.

Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call