Microstructure and elemental analysis of ZnO-coated AZ91D magnesium alloy via anodic oxidation coating for corrosion protection

L. Y. Vee; Ts. Dr. Mohd Zamzuri Mohammad Zain; Z. Iberahim; N. Zainon; H. Jaafar; A. F. Aiman; C. C. Lee

doi:10.15282/jmes.19.1.2025.2.0819

Authors

L. Y. Vee Faculty of Mechanical Engineering Technology, Universiti Malaysia Perlis, Pauh Putra Main Campus, 02600 Arau, Perlis, Malaysia
M. Zamzuri Faculty of Mechanical Engineering Technology, Universiti Malaysia Perlis, Pauh Putra Main Campus, 02600 Arau, Perlis, Malaysia. Phone: +6049885035; Fax.: +6049885034
Z. Iberahim Department of Mechanical Engineering, Politeknik Kota Kinabalu, No.4 Jalan Politeknik, KKIP Barat, Kota Kinabalu Industrial Park, 88460 Kota Kinabalu Sabah, Malaysia
N. Zainon Faculty of Mechanical Engineering Technology, Universiti Malaysia Perlis, Pauh Putra Main Campus, 02600 Arau, Perlis, Malaysia
H. Jaafar Faculty of Mechanical Engineering Technology, Universiti Malaysia Perlis, Pauh Putra Main Campus, 02600 Arau, Perlis, Malaysia
A. F. Aiman Faculty of Mechanical Engineering Technology, Universiti Malaysia Perlis, Pauh Putra Main Campus, 02600 Arau, Perlis, Malaysia
C. C. Lee Faculty of Mechanical Engineering Technology, Universiti Malaysia Perlis, Pauh Putra Main Campus, 02600 Arau, Perlis, Malaysia

DOI:

https://doi.org/10.15282/jmes.19.1.2025.2.0819

Keywords:

Mg alloy, Zinc oxide, Anodic oxidation coating, Coating time, Corrosion protection

Abstract

The AZ91D Magnesium alloy is a highly demanded structural material, valued for its exceptional mechanical and physical properties. Its versatility has led to widespread applications in industries such as automotive, aerospace, electronics, and biomedical. However, a significant limitation of AZ91D alloy is its poor corrosion resistance, which hinders broader adoption despite its advantages. To mitigate this weakness, surface treatments are essential to improve its corrosion protection. Among the various methods, anodizing stands out due to its low operational cost, short processing time, and straightforward setup. This research investigates the effect of coating time on the quality of anodic oxidation coatings with zinc oxide (ZnO) on AZ91D Magnesium alloy. The surface morphology, structural characteristics, and corrosion resistance of the ZnO-coated alloy were analyzed using Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), and corrosion testing. The findings demonstrate that anodizing effectively increased the thickness of the ZnO oxide layer on the AZ91D Magnesium alloy, significantly improving its corrosion resistance. Notably, the coating thickness increased proportionally with the duration of coating time. The sample with a 3-minute coating time exhibited the lowest corrosion rate of 2.17 mm/year, alongside the best coating quality, as confirmed by SEM, EDX, and XRD analysis. These results indicate that the elemental composition and compactness of the coating layer play a critical role in enhancing corrosion resistance.

References

[1] F. B. Gong, J. Shen, R. H. Gao, X. Xie, X. Luo, “Enhanced corrosion resistance of magnesium alloy by a silane-based solution treatment an in-situformation of Mg(OH)2 layer,” Applied Surface Science, vol. 365, pp. 268–274, 2016.

[2] G. Wu, J. M. Ibrahim, P. K. Chu, “Surface design of biodegradable magnesium alloy – A review,” Surface Coating Technology, vol. 233, pp. 2–12, 2013.

[3] M. Esmaily, J. E. Svensson, S. Fajardo, N. Birbilis, G. S. Frankel, S. Virtanen, et al., “Fundamentals and advances in magnesium alloy corrosion,” Progress in Materials Science, vol. 89, pp. 92–193, 2017.

[4] M. Zamzuri, N. Sidik, M.Derman, S. Norbahiyah, M. Mat Salleh, “Improvement of corrosion resistance of AZ91D Magnesium alloy by Lanthanum-based conversion coating,” Journal of Industrial Technology, vol. 21, no. 1, pp. 53–61, 2013.

[5] N. Sidik, M. Zamzuri, M. Mat Salleh, K. A. Ismail, “Effect of NaVO3 concentration on corrosion resistance of conversion coating on AZ91D magnesium alloy,” Advanced Materials Research, vol. 576, pp. 438–441, 2012.

[6] K. Qian, Y. Zhang, Q. Dong, Y. Shao, Z. Cheng, J. Ju, et al., “Enhancement of corrosion resistance and antibacterial properties of PEO coated AZ91D Mg alloy by copper-and phosphate-based sealing treatment,” Corrosion Science, vol. 219, pp. 111218, 2023.

[7] Z. Tian, S. Li, Y. Chen, L. Li, Z. An, Y. Zhang, et al., “Self-healing coating with a controllable release of corrosion inhibitors by using multifunctional zinc oxide quantum dots as valves,” ACS Applied Materials & Interfaces, vol. 14, no. 41, pp. 47188–47197, 2022.

[8] H. Byeon, V. S. Sreenivasan, A. R. Krishna, C. P. Thosar, S. B. Randhavane, DS Baghel, et al., “Employing zinc oxide nanoparticle coating as a corrosion inhibitor for magnesium alloys in distinct aqueous electrolyte,” Bulletin of the Chemical Society of Ethiopia, vol. 38, no. 2, pp. 417–430, 2024.

[9] V. Z. Asl, S. F. Chini, J. Zhao, Y. Palizdar, M. Shaker, A. Sadeghi, et al., “Corrosion properties and surface free energy of the Zn single bond Al LDH/rGO coating on MAO pretreated AZ31 magnesium alloy,” Surface and Coatings Technology, vol. 426, p. 127764, 2021.

[10] Y. Chen, L. Wu, W. Yao, J. Wu, Y. Yuan, B. Jiang, et al., “Growth behavior and corrosion resistance of graphene oxide/MgAl Layered double hydroxide coating grown on micro-arc oxidation film of magnesium alloys,” Journal of Industrial and Engineering Chemistry, vol. 117, pp. 319–332, 2023.

[11] J. Yuan, R. Yuan, J. Wang, Q. Li, X. Xing, X. Liu, et al., “Fabrication and corrosion resistance of phosphate/ZnO multilayer protective coating on magnesium alloy,” Surface & Coatings Technology, vol. 352, pp. 74–83, 2018.

[12] Z. Iberahim, M. Zamzuri, A. H. Ismail, N. S. Mun, F. I. Subri, N. Zainon, et al., “Analysis of multilevel Otsu thresholding for corrosion rate of anodised AZ91D magnesium alloy,” Journal of Engineering and Science Research, vol. 6, pp. 6–11, 2022.

[13] L. Guo, W. Wu, Y. Zhou, F. Zhang, R. Zeng, J. Zeng, “Layered double hydroxide coatings on magnesium alloys: A review,” Journal of Materials Science & Technology, vol. 34, no. 9, pp. 1455–1466, 2018.

[14] S. Chatterjee, “Titanate incorporated anodized coating on magnesium alloy for corrosion protection, antibacterial responses and osteogenic enhancement,” Journal of Magnesium and Alloys, vol. 10, no. 4, pp. 1109–1123, 2022.

[15] J. Zhu, C. Jia, “Electrochemical studies on ammonium magnesium carbonate tetrahydrate/calcium carbonate composite coating on AZ91D magnesium alloy,” Materials Chemistry and Physics, vol. 292, p. 126787, 2022.

[16] Y. Tang, B. Li, H. Shi, Y. Guo, J. Zhang, X. Zhang, et al., “Study on the role of solution treatment on corrosion behavior of duplex lightweight steel in different environments,” Electrochimica Acta, vol. 469, p. 143254, 2023.

[17] S. V. Lamaka, B. Vaghefinazari, D. Mei, R. P. Petrauskas, D. Höche, M. L. Zheludkevich, “Comprehensive screening of Mg corrosion inhibitors,” Corrosion Science, vol. 128, pp. 224–240, 2017.

[18] C. Verma, E. E. Ebenso, M. A. Quraishi, “Corrosion inhibitors for ferrous and non-ferrous metals and alloys in ionic sodium chloride solutions: A review," Journal of Molecular Liquids, vol. 248, pp. 927–942, 2017.

[19] R. A. Patil, M. Talebi, C. Xu, S. S. Bhawal, D. W. Armstrong, “Synthesis of thermally stable geminal dicationic ionic liquids and related ionic compounds: An examination of physicochemical properties by structural modification,” Chemistry of Materials, vol. 28, no. 12, pp. 4315–4323, 2016

[20] M. Forsyth, W. C. Neil, P. C. Howlett, D. R. Macfarlane, B. R. W. Hinton, N. Rocher, et al., “New insights into the fundamental chemical nature of ionic liquid film formation on magnesium alloy surfaces,” ACS Applied Materials & Interfaces, vol. 1, no. 5, pp. 1045–1052, 2009.

[21] X. Xiao, G. Hu, Y. Liang, P. Yan, A. Jiang, “A review on the properties of zinc oxide nanoparticles in various industries and biomedical fields: Enhancing chemical and physical characteristics,” Iranian Journal of Chemistry and Chemical Engineering, vol. 43, no. 1, pp. 46–65, 2024.

[22] Y. Liu, H. Yao, L. Wu, Z. H. Xie, C. J. Zhong, “Temperature-controlled and shape-dependent ZnO/TiO2 heterojunction for photocathodic protection of nickel-coated magnesium alloys," Applied Surface Science, vol. 614, p. 156109, 2023.

[23] H. M. Mousa, A. Abdal-Hay, M. Bartnikowski, I. M. A. Mohamed, A. S. Yasin, S. Ivanovski, “A multifunctional zinc oxide/poly (lactic acid) nanocomposite layer coated on magnesium alloys for controlled degradation and antibacterial function,” ACS Biomaterials Science & Engineering, vol. 4, no. 6, pp. 2169–2180, 2018.

[24] Y. Guo, S. Jia, L. Qiao, Y. Su, R. Gu, G. Li, et al., “A multifunctional polypyrrole/zinc oxide composite coating on biodegradable magnesium alloys for orthopedic implants,” Colloids and Surfaces B: Biointerfaces, vol. 194, p. 111186, 2020.

[25] A. Basheer Ahmed, “Anodizing of magnesium alloy AZ31 by alkaline solution,” Diyala Journal of Engineering Sciences, vol. 8, no. 1, pp. 110–119, 2015.

[26] L. Kumari, W. Z. Li, C. H. Vannoy, R. M. Leblanc, D. Z. Wang, “Synthesis, characterization and optical properties of Mg (OH) 2 micro-/nanostructure and its conversion to MgO,” Ceramics International, vol. 35, no. 8, pp. 3355–3364, 2009.

[27] M. P. Martínez-Viademonte, S. T. Abrahami, T. Hack, M. Burchardt, H. Terryn, “A review on anodizing of aerospace aluminum alloys for corrosion protection,” Coatings, vol. 10, no. 11, p. 1106, 2020.

[28] A. Zaffora, F. D. Franco, D. Virtù, F. C. Pavia, G. Ghersi, S. Virtanen, et al., “Tuning of the Mg alloy AZ31 anodizing process for biodegradable implants,” ACS Applied Materials & Interfaces, vol. 13, no. 11, pp. 12866–12876, 2021.

[29] W. He, Z. Shao, J. He, Y. Zhang, M. Sun, Y. Jiang, Z. Wen, F. Chen et al., “Enhanced anticorrosive, antimicrobial and bincompatible properties of AZ91D magnesium alloy by MAO-polycaprolactone-modified ZnO composite coating,” Surface Coatings Technology, vol. 494, pp. 131484, 2024.