Passivation is a frequently used method to strengthen the surface of aluminum alloys. This study fabricated two zirconium-rich passive layers on the Al alloy. The morphology, thickness, and chemical composition of the prepared coating were analyzed employing XPS and TEM. Electrochemical impedance spectroscopy and Tafel polarization tests are also used to assess the anticorrosive performance. The passivation layers exhibit a dual-layer structure, with thicknesses ranging from 16 nm to 26 nm. Chemical composition of the two component layers is different. Electrochemical tests confirm a significant improvement in anticorrosive performance for both passivated samples compared to the untreated substrate. The study offers insights into the bonding mechanisms and layered architecture of the passivation film, contributing to the development of non-toxic, high-performance surface treatment technologies for aluminum alloys.
Li et al. (Thu,) studied this question.