Skip to main content
Log in

Electrochemical behaviors of magnesium alloy with phosphate conversion coating in NaCl solutions

  • Published:
Rare Metals Aims and scope Submit manuscript

Abstract

A composite conversion coating was prepared on magnesium alloy by the only one-step immersion treatment. The characteristics of the conversion coating were investigated by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results indicate that the composite conversion coating consists of magnesium hydroxide, magnesium phosphate and manganese phosphate. The electrochemical behavior of the conversion coating was investigated systematically by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurement in different NaCl solutions. Polarization measurements and EIS results reveal that the magnesium alloy with the conversion coating have better corrosion resistance compared to the bare magnesium alloy in these conditions. And the corrosion rate of the magnesium alloy with conversion coating increases consistently with the chloride ion concentration. In alkaline conditions, the magnesium alloy with conversion coating has superior corrosion resistance by the synergistic effects between Mg(OH)2 film and conversion coating. Moreover, the electrochemical corrosion mechanism of the magnesium alloy was analyzed with respect to the conversion coating in a Cl containing environment.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9

Similar content being viewed by others

References

  1. Chen XB, Zhou X, Abbott TB, Easton MA, Birbilis N. Double-layered manganese phosphate conversion coating on magnesium alloy AZ91D: insights into coating formation, growth and corrosion resistance. Surf Coat Technol. 2013;217:147.

    Article  Google Scholar 

  2. Gray JE, Luan B. Protective coatings on magnesium and its alloys—a critical review. J Alloys Compd. 2002;336(1–2):88.

    Article  Google Scholar 

  3. Huo H, Li Y, Wang F. Corrosion of AZ91D magnesium alloy with a chemical conversion coating and electroless nickel layer. Corros Sci. 2004;46(6):1467.

    Article  Google Scholar 

  4. Xu W, Song J, Sun J, Lu Y, Yu Z. Rapid fabrication of large-area, corrosion-resistant superhydrophobic Mg alloy surfaces. ACS Appl Mater Interfaces. 2011;3(11):4404.

    Article  Google Scholar 

  5. Atrens A, Song GL, Liu M, Shi ZM, Cao FY, Dargusch MS. Review of recent developments in the field of magnesium corrosion. Adv Eng Mater. 2015;17(4):400.

    Article  Google Scholar 

  6. Alvarez-Lopez M, Pereda MD, del Valle JA, Fernandez-Lorenzo M, Garcia-Alonso MC, Ruano OA, Escudero ML. Corrosion behaviour of AZ31 magnesium alloy with different grain sizes in simulated biological fluids. Acta Biomater. 2010;6(5):1763.

    Article  Google Scholar 

  7. Gao R, Liu Q, Wang J, Zhang X, Yang W, Liu J, Liu L. Fabrication of fibrous szaibelyite with hierarchical structure superhydrophobic coating on AZ31 magnesium alloy for corrosion protection. Chem Eng J. 2014;241:352.

    Article  Google Scholar 

  8. Yue YY, Liu ZX, Wan TT, Wang PC. Effect of phosphate–silane pretreatment on the corrosion resistance and adhesive-bonded performance of the AZ31 magnesium alloys. Prog Org Coat. 2013;76(5):835.

    Article  Google Scholar 

  9. Wang J, Li D, Yu X, Jing X, Zhang M, Jiang Z. Hydrotalcite conversion coating on Mg alloy and its corrosion resistance. J Alloys Compd. 2010;494(1–2):271.

    Article  Google Scholar 

  10. Chen XB, Birbilis N, Abbott TB. Review of corrosion-resistant conversion coatings for magnesium and its alloys. Corrosion. 2011;67(3):035005-1.

    Article  Google Scholar 

  11. Khaselev O, Weiss D, Yahalom J. Structure and composition of anodic films formed on binary Mg–Al alloys in KOH–aluminate solutions under continuous sparking. Corros Sci. 2001;43(7):1295.

    Article  Google Scholar 

  12. Song YW, Shan DY, Han EH. High corrosion resistance of electroless composite plating coatings on AZ91D magnesium alloys. Electrochim Acta. 2008;53(5):2135.

    Article  Google Scholar 

  13. Blawert C, Dietzel W, Ghali E, Song GL. Anodizing treatments for magnesium alloys and their effect on corrosion resistance in various environments. Adv Eng Mater. 2006;8(6):511.

    Article  Google Scholar 

  14. Liu C, Xin Y, Tian X, Zhao J, Chu PK. Corrosion resistance of titanium ion implanted AZ91 magnesium alloy. J Vac Sci Technol A. 2007;25(2):334.

    Article  Google Scholar 

  15. Li Z, Zhang JW, Meng GZ, Sun FL, Shao YW, Zhang T. Electrochemical corrosion behavior of 17-4PH stainless steel with laser surface melting treatment. J Chin Soc Corros Prot. 2012;32(3):210.

    Google Scholar 

  16. Saha GC, Khan TI, Zhang GA. Erosion–corrosion resistance of microcrystalline and near-nanocrystalline WC–17Co high velocity oxy-fuel thermal spray coatings. Corros Sci. 2011;53(6):2106.

    Article  Google Scholar 

  17. Tian BR, Cheng YF. Electrolytic deposition of Ni–Co–Al2O3 composite coating on pipe steel for corrosion/erosion resistance in oil sand slurry. Electrochim Acta. 2007;53(2):511.

    Article  Google Scholar 

  18. Yang Y, Cheng YF. Electrolytic deposition of Ni–Co–SiC nano-coating for erosion-enhanced corrosion of carbon steel pipes in oilsand slurry. Surf Coat Technol. 2011;205(10):3198.

    Article  Google Scholar 

  19. Ishizaki T, Kudo R, Omi T, Teshima K, Sonoda T, Shigematsu I, Sakamoto M. Magnesium hydroxide/magnesium phosphate compounds composite coating for corrosion protection of magnesium alloy by a combination process of chemical conversion and steam curing. Mater Lett. 2012;68:122.

    Article  Google Scholar 

  20. Lin CS, Lee CY, Li WC, Chen YS, Fang GN. Formation of phosphate/permanganate conversion coating on AZ31 magnesium alloy. J Electrochem Soc. 2006;153(3):B90.

    Article  Google Scholar 

  21. Niu LY, Jiang ZH, Li GY, Gu CD, Lian JS. A study and application of zinc phosphate coating on AZ91D magnesium alloy. Surf Coat Technol. 2006;200(9):3021.

    Article  Google Scholar 

  22. Okido M, Ichino R, Kim SJ, Jang SK. Surface characteristics of chemical conversion coating for Mg–Al alloy. Trans Nonferr Met Soc China. 2009;19(4):892.

    Article  Google Scholar 

  23. Cui X, Liu CH, Yang RS, Li MT, Lin XZ, Gong M. Phosphate film free of chromate, fluoride and nitrite on AZ31 magnesium alloy and its corrosion resistance. Trans Nonferr Met Soc China. 2012;22(11):2713.

    Article  Google Scholar 

  24. Chen Y, Luan BL, Song GL, Yang Q, Kingston DM, Bensebaa F. An investigation of new barium phosphate chemical conversion coating on AZ31 magnesium alloy. Surf Coat Technol. 2012;210:156.

    Article  Google Scholar 

  25. Mizutani Y, Kim SJ, Ichino R, Okido M. Anodizing of Mg alloys in alkaline solutions. Surf Coat Technol. 2003;169–170:143.

    Article  Google Scholar 

  26. Xue D, Tan Z, Schulz MJ, Vanooij WJ, Sankar J, Yun Y, Dong Z. Corrosion studies of modified organosilane coated magnesium–yttrium alloy in different environments. Mater Sci Eng C. 2012;32(5):1230.

    Article  Google Scholar 

  27. Mandelli A, Bestetti M, Da Forno A, Lecis N, Trasatti SP, Trueba M. A composite coating for corrosion protection of AM60B magnesium alloy. Surf Coat Technol. 2011;205(19):4459.

    Article  Google Scholar 

  28. Doepke A, Xue D, Yun Y, Vanooij WJ, Halsall HB, Heineman WR. Corrosion of organosilane coated Mg4Y alloy in sodium chloride solution evaluated by impedance spectroscopy and pH changes. Electrochim Acta. 2012;70:165.

    Article  Google Scholar 

  29. Rudd AL, Breslin CB, Mansfeld F. The corrosion protection afforded by rare earth conversion coatings applied to magnesium. Corros Sci. 2000;42(2):275.

    Article  Google Scholar 

  30. Wang C, Zhu SL, Jiang F, Wang FH. Cerium conversion coatings for AZ91D magnesium alloy in ethanol solution and its corrosion resistance. Corros Sci. 2009;51(12):2916.

    Article  Google Scholar 

  31. Brunelli K, Dabala M, Calliari I, Magrini M. Effect of HCl pre-treatment on corrosion resistance of cerium-based conversion coatings on magnesium and magnesium alloys. Corros Sci. 2005;47(4):989.

    Article  Google Scholar 

  32. Zhou WQ, Shan DY, Han EH, Ke W. Structure and formation mechanism of phosphate conversion coating on die-cast AZ91D magnesium alloy. Corros Sci. 2008;50(2):329.

    Article  Google Scholar 

  33. Han EH, Zhou WQ, Shan DY, Ke W. Corrosion and protection of magnesium alloy AZ31D by a new conversion coating. Mater Sci Forum. 2003;419:879.

    Article  Google Scholar 

  34. Zhou WQ, Shan DY, Han EH, Ke W. Phosphate conversion coating on diecast AZ91D and its corrosion resistance. Mater Sci Forum. 2005;488:819.

    Article  Google Scholar 

  35. Howlett PC, Gramet S, Lin J, Efthimiadis J, Chen XB, Birbilis N, Forsyth M. Conversion coatings of Mg-alloy AZ91D using trihexyl (tetradecyl) phosphonium bis (trifluoromethanesulfonyl) amide ionic liquid. Sci China Chem. 2012;55(8):1598.

    Article  Google Scholar 

  36. Zucchi F, Frignani A, Grassi V, Trabanelli G, Monticelli C. Stannate and permanganate conversion coatings on AZ31 magnesium alloy. Corros Sci. 2007;49(12):4542.

    Article  Google Scholar 

  37. Akhtar AS, Wong KC, Mitchell KAR. The effect of pH and role of Ni2+ in zinc phosphating of 2024-Al alloy: part I: macroscopic studies with XPS and SEM. Appl Surf Sci. 2006;253(2):493.

    Article  Google Scholar 

  38. da Silva CG, Correia AN, de Lima-Neto P, Margarit ICP, Mattos OR. Study of conversion coatings obtained from tungstate-phosphoric acid solutions. Corros Sci. 2005;47(3):709.

    Article  Google Scholar 

  39. Chen XB, Birbilis N, Abbott TB. A simple route towards a hydroxyapatite–Mg(OH)2 conversion coating for magnesium. Corros Sci. 2011;53(6):2263.

    Article  Google Scholar 

  40. Li GY, Lian JS, Niu LY, Jiang ZH, Jiang Q. Growth of zinc phosphate coatings on AZ91D magnesium alloy. Surf Coat Technol. 2006;201(3):1814.

    Article  Google Scholar 

  41. Zhao MC, Liu M, Song GL, Atrens A. Influence of pH and chloride ion concentration on the corrosion of Mg alloy ZE41. Corros Sci. 2008;50(11):3168.

    Article  Google Scholar 

  42. Lasia A. Electrochemical Impedance Spectroscopy and Its Applications. In: Conway BE, Bockris JOM, White R, editors. Modern Aspects of Electrochemistry. New York: Kluwer Academic/Plenum Publishers; 2002. 143.

  43. Meng GZ, Zhang C, Cheng YF. Effects of corrosion product deposit on the subsequent cathodic and anodic reactions of X-70 steel in near-neutral pH solution. Corros Sci. 2008;50(11):3116.

    Article  Google Scholar 

  44. Amini R, Sarabi AA. The corrosion properties of phosphate coating on AZ31 magnesium alloy: the effect of sodium dodecyl sulfate (SDS) as an eco-friendly accelerating agent. Appl Surf Sci. 2011;257(16):7134.

    Article  Google Scholar 

  45. Yang YC, Tsai CY, Huang YH, Lin CS. Formation mechanism and properties of titanate conversion coating on AZ31 magnesium alloy. J Electrochem Soc. 2012;159(5):C226.

    Article  Google Scholar 

  46. Banerjee PC, Raman RKS. Electrochemical impedance spectroscopic investigation of the role of alkaline pre-treatment in corrosion resistance of a silane coating on magnesium alloy, ZE41. Electrochim Acta. 2011;56(11):3790.

    Article  Google Scholar 

  47. Song GL, Atrens A. Corrosion mechanisms of magnesium alloys. Adv Eng Mater. 1991;1(1):11.

    Article  Google Scholar 

Download references

Acknowledgments

This study was financially supported by the National Natural Science Foundation of China (No. 51222106), the Fundamental Research Funds for the Central Universities (No. 230201306500002) and the National Basic Research Program of China (No. 2014CB643300).

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Chao-Fang Dong.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Fu, LH., Dong, CF., Li, XG. et al. Electrochemical behaviors of magnesium alloy with phosphate conversion coating in NaCl solutions. Rare Met. 35, 747–757 (2016). https://doi.org/10.1007/s12598-016-0784-6

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s12598-016-0784-6

Keywords

Navigation