Electrochemical corrosion resistance of aluminum alloy 6101 with cerium-based coatings in an alkaline environment

Ahsan Riaz Khan; Hai-Jun Zhang; Zhang Jun; Sayed M Eldin; Norah Saleem Alsaiari; Khadijah Mohammedsaleh Katubi

doi:10.3389/fchem.2022.1066958

Electrochemical corrosion resistance of aluminum alloy 6101 with cerium-based coatings in an alkaline environment

Front Chem. 2022 Nov 14:10:1066958. doi: 10.3389/fchem.2022.1066958. eCollection 2022.

Authors

Ahsan Riaz Khan^{1

2

3}, Hai-Jun Zhang^{1

2}, Zhang Jun^{4

5}, Sayed M Eldin⁶, Norah Saleem Alsaiari⁷, Khadijah Mohammedsaleh Katubi⁷

Affiliations

¹ Department of Interventional and Vascular Surgery, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.
² National United Engineering Laboratory for Biomedical Material Modification, Branden Industrial Park, Qihe Economic & Development Zone, Dezhou, Shandong, China.
³ Department of Chemical Engineering, Northwest University, Xi'an, China.
⁴ Research Center for Translational Medicine, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China.
⁵ Shanghai Institute of Stem Cell Research and Clinical Translation, Shanghai, China.
⁶ Center of Research, Faculty of Engineering, Future University in Egypt, New Cairo, Egypt.
⁷ Department of Chemistry, College of Science, Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia.

Abstract

Chromium-free materials as eco-friendly coatings with higher corrosion resistance are crucial in various industrial processes. Herein, we report the deposition of cerium-based conversion, a chromium-free, eco-friendly chemical conversion coating for aluminum alloy 6101, by the dip coating method. Immersion in cerium salt precursors assisted with hydrogen peroxide was performed for the deposition of cerium-based conversion coatings on aluminum alloy 6101 at different bathing temperatures. The electrochemical corrosion behavior was assessed in an alkaline solution of sodium hydroxide (pH 11), including mass loss measurements, free corrosion risk, polarization, and electrochemical impedance spectroscopy. X-ray diffraction and photoelectron spectroscopy analysis showed that the coatings were composed of Ce (III) and Ce (IV) oxides. Surface modifications and surface degradation of the coating and substrate after immersion in corrosive media were analyzed by scanning electron microscopy. Additionally, energy dispersive scanning analysis demonstrated the elemental composition before and after corrosion of the cerium salt conversion-based coating. The results demonstrated that selectively deposited cerium-based conversion coatings improved the corrosion resistance by up to 96% in a strong corrosive alkaline media.

Keywords: cerium; coating; conversion; corrosion; electrochemistry.