J. Mater. Sci. Technol. ›› 2025, Vol. 224: 312-327.DOI: 10.1016/j.jmst.2024.10.023

• Research Article • Previous Articles     Next Articles

Simultaneous improvement of wear and corrosion resistance of microarc oxidation coatings on ZK61 Mg alloy by doping with ZrO2 nanoparticles

Chao Yanga, Chenyu Wanga, Zhao Shena,b,*, Liping Zhoua, Liyuan Shengc,d,**, Daokui Xue, Yufeng Zhengc, Paul K. Chuf, Shu Xiaog,*, Tao Yinga, Xiaoqin Zenga   

  1. aNational Engineering Research Center of Light Alloy Net Forming and State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China;
    bInstitute of Medical Robotics, Shanghai Jiao Tong University, Shanghai 200240, China;
    cShenzhen Institute, Peking University, Shenzhen 518057, China;
    dPKU-HKUST Shenzhen-Hong Kong Institution, Shenzhen 518057, China;
    eKey Laboratory of Nuclear Materials and Safety Assessment, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China;
    fDepartment of Physics, Department of Materials Science & Engineering, and Department of Biomedical Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong 999077, China;
    gSchool of Mechanical & Automotive Engineering, South China University of Technology, Guangzhou 510641, China
  • Received:2024-09-18 Revised:2024-10-22 Accepted:2024-10-25 Published:2025-07-20 Online:2024-11-15
  • Contact: *E-mail addresses: shenzhao081@sjtu.edu.cn (Z. Shen), lysheng@yeah.net (L. Sheng), xiaos@scut.edu.cn (S. Xiao). **Corresponding author at: PKU-HKUST Shenzhen-Hong Kong Institution, Shen- zhen 518057, China.

Abstract: The poor corrosion resistance of magnesium (Mg) and its alloys limits their application in various fields. Micro arc oxidation (MAO) coatings can improve the corrosion resistance, but the pore defects and low surface hardness make them susceptible to wear and accelerated corrosion during usage. In this study, a ZrO2 nanoparticles doped-MAO coating is prepared on the ZK61 Mg alloy by utilizing an MgF2 passivation layer to prevent ablation. The ZrO2 nanoparticles re-melt and precipitate due to local discharging, which produces evenly dispersed nanocrystals in the MAO coating. As a result, the hardness of the MAO coating with the appropriate ZrO2 concentration increases by over 10 times, while the wear rate decreases and corrosion resistance increases. With increasing ZrO2 concentrations, the corrosion potentials increase from -1.528 V of the bare ZK61 Mg alloy to -1.184 V, the corrosion current density decreases from 1.065 × 10-4 A cm-2 to 3.960 × 10-8 A cm-2, and the charge transfer resistance increases from 3.41 × 102 Ω cm2 to 6.782 × 105Ω cm2. Immersion tests conducted in a salt solution for 28 d reveal minimal corrosion in contrast to severe corrosion on the untreated ZK61 Mg alloy. ZrO2 nanoparticles improve the corrosion resistance of MAO coatings by sealing pores and secondary strengthening of the corrosion product layer.

Key words: ZK61 Mg alloy, Micro arc oxidation, ZrO2 doping, MgF2, Wear resistance, Corrosion resistance