Acta Metallurgica Sinica (English Letters) ›› 2025, Vol. 38 ›› Issue (11): 2001-2023.DOI: 10.1007/s40195-025-01910-5

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Evaluation of Corrosion Resistance for ZIF-67@Co-M (M = Fe, Al, Ni) LDHs Composite Coatings Based on AZ31 Magnesium Alloy

Yonghua Chen1, Zhenzhen Tian1, Fubing Yu1, Mingyi Wu1, Wenhui Yao1,2, Yuantai He1, Yuan Yuan1,2, Zhihui Xie3, Guozhi Wu4, Jiahao Wu5, Fusheng Pan1,2, Liang Wu1,2()   

  1. 1National Engineering Research Center for Magnesium Alloys, College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China
    2State Key Laboratory of Mechanical Transmission, Chongqing University, Chongqing 400044, China
    3Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, College of Chemistry and Chemical Engineering, China West Normal University, Nanchong 637002, China
    4College of Materials and Environmental Engineering, Chizhou University, Chizhou 247000, China
    5School of Chemistry and Chemical Engineering, Sichuan University of Arts and Science, Dazhou 635000, China
  • Received:2025-03-19 Revised:2025-04-28 Accepted:2025-05-14 Online:2025-11-10 Published:2025-08-19
  • Contact: Liang Wu, wuliang@cqu.edu.cn

Abstract:

The widespread application of magnesium (Mg) and Mg alloys is limited by their poor corrosion resistance. Micro-arc oxidation (MAO) is a common surface treatment, but the inherent defects of the MAO coating require post-treatment to ensure good corrosion protection. Therefore, various zeolitic imidazolate framework ZIF-67@Co-M (M = Fe, Al, Ni) layered double hydroxides (LDHs) composite coatings were fabricated on MAO-treated AZ31 Mg alloy to enhance its corrosion resistance. The surface characteristics, coating thickness, corrosion resistance and protection mechanisms of the ZCM (ZIF-67@Co-M LDHs) composite coatings were examined. The findings indicate that the ZCF (ZIF-67@Co-Fe LDHs) composite coating exhibits the lowest corrosion current density (icorr = 7.76 × 10-8 A/cm2), superior corrosion resistance, the lowest corrosion rate (HEV = 2.46 mL·cm-2) and the fastest response speed to corrosion. The synergistic integration of ZIF-67 and LDHs effectively prevents the invasion of corrosive media, enhancing both short-term and long-term corrosion resistance of AZ31 alloys. These composite coatings surpass the limitations of individual materials, providing a promising strategy for durable corrosion protection.

Key words: Mg alloy, Micro-arc oxidation (MAO), Zeolitic imidazolate framework (ZIF-67), Layered double hydroxides (LDHs), Coating, Anti-corrosion