New anodizing process for magnesium alloys

  • Luo Sheng-lian 
  • Dai Lei 
  • Zhou Hai-hui 
  • Chai Li-yuan 
  • Kuang Ya-fei Email author


Compact anodic films with high hardness and good corrosion resistance on magnesium alloys were prepared by a new constant voltage and arc-free anodizing process. The effects of anodizing parameters such as applied voltage and electrolyte temperature on the peak current density and the thickness of films were investigated. In addition, the morphologies and corrosion resistance of films were investigated by scanning electron microscopy and potentiodynamic polarization, respectively. The results show that the higher the applied voltage, the higher the peak intense sparking which may deteriorate the properties of the anodic films and bring about unsafety. The new anodizing process can be applied in a wide range of temperature. The new anodic films have numbers of pores with the diameter of 0.5–5.0 µm which do not transverse the entire film.

Key words

magnesium alloys anodizing film arc-free corrosion resistance 

CLC number

TG174. 451 


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  1. [1]
    Ambat R, Aung N, Zhou W. Evaluation of microstructural effects on corrosion behavior of AZ91D magnesium alloys[J]. Corrosion Science, 2000, 42 (8): 1433–1455.CrossRefGoogle Scholar
  2. [2]
    Nishikawa Y. Development of electric products using magnesium alloys[J]. Function and Materials, 1999, 19(6): 21–27. (in Japanese).Google Scholar
  3. [3]
    Gray J E, Luan B. Protective coatings on magnesium and its alloys: a critical review[J]. Journal of Alloys and Compounds, 2002, 336(1): 88–113.CrossRefGoogle Scholar
  4. [4]
    Bartak D E, Lemieux B E, Woolsey E R. Two-step electrochemical process for coating magnesium alloys. US, 5264113[P]. 1993 - 11 - 23.Google Scholar
  5. [5]
    Sachiko O, Katshiko A, Tesuya O, et al. Structure of anodic films formed on magnesium[J]. Journal of the Electrochemical Society, 1996, 143(3): 62-L63.CrossRefGoogle Scholar
  6. [6]
    Barton T F. Anodization of magnesium and magnesium based alloys. US, 5792335[P]. 1998 - 08 - 11.Google Scholar
  7. [7]
    Kobayashi W, Uehori K, Furuta M. Anodizing solution for anodic oxidation of magnesium or its alloys. US, 4744872[P]. 1988 - 03 - 17.Google Scholar
  8. [8]
    Mizutani Y, Kim S J, Ichino R. Anodizing of Mg alloys in alkaline solution[J]. Surface and Coatings Technology, 2003, 169(1): 143–146.CrossRefGoogle Scholar
  9. [9]
    Zozulin A J, Bartak D E. Anodized coatings for magnesium alloys[J]. Metal Finishing, 1994, 92(3): 39–44.Google Scholar
  10. [10]
    Bartak D E, Lemieux B E, Woolsey E R. Hard anodic coating for magnesium alloys. US, 5470664[P]. 1995 - 11 - 28.Google Scholar
  11. [11]
    Abulsain M, Berkani A, Bonilla F A, et al. Anodic oxidation of Mg-Cu and Mg-Zn alloys[J]. Electrochimica Acta, 2004, 49(6): 899–904.CrossRefGoogle Scholar
  12. [12]
    Khaselev O, Weiss D. Anodizing of pure magnesium in KOH-aluminate solutions under sparking [J]. Journal of the Electrochemical Soceity, 1999, 146(5): 1757–1761.CrossRefGoogle Scholar
  13. [13]
    Bonilla F A, Berkani A, Skeldon P, et al. Formation of anodic films on magnesium alloys in an alkaline phosphate electrolyte[J]. Journal of the Electrochemical Society, 2002, 149(1): B4-B13.CrossRefGoogle Scholar
  14. [14]
    Sharma A K, Rani R U, Giri K. Studies on anodization of magnesium alloy for thermal control applications[J]. Metal Finishing, 1997, 95(3): 43–51.CrossRefGoogle Scholar
  15. [15]
    Khaselev O, Yahalom J. Constant voltage anodizing of Mg-Al alloys in KOH-Al (OH)3 solutions [J]. Journal of the Electrochemical Society, 1998, 145(1): 190–193.CrossRefGoogle Scholar
  16. [16]
    Schmeling E L, Roschenbleck B, Weidemann M H. Method of producing protective coatings that are resistant to corrosion and wear on magnesium and magnesium alloys. US, 4978432[P]. 1990 - 12 - 18.Google Scholar
  17. [17]
    Kurze P, Banerjee D, Kletke H J. Method of producing oxide ceramic layers on barrier layer-forming metals and articles produced by the method. US, 5385662[P]. 1995 - 01 - 31.Google Scholar
  18. [18]
    Khaselev O, Yahalom J. The anodic behavior of binary Mg-Al alloys in KOH-aluminate solution[J]. Corrosion Science, 1998, 40(7): 1149–1160.CrossRefGoogle Scholar
  19. [19]
    Hsiao H Y, Tsung H C, Tsai W T. Anodization of AZ91D magnesiumalloy in silicate-containing electrolytes[J]. Surface and Coatings Technology, 2005, 199(2): 127–134.CrossRefGoogle Scholar

Copyright information

© Central South University 2006

Authors and Affiliations

  • Luo Sheng-lian 
    • 1
    • 2
  • Dai Lei 
    • 2
  • Zhou Hai-hui 
    • 2
  • Chai Li-yuan 
    • 1
  • Kuang Ya-fei 
    • 2
    Email author
  1. 1.School of Metallurgical Science and EngineeringCentral South UniversityChangshaChina
  2. 2.School of Chemistry and Chemical EngineeringHunan UniversityChangshaChina

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