Surface Analysis of Magnesium AZ31 Samples Immersed in Various Aqueous Solutions

Abstract

Rapid degradation in body fluids is known to be the main shortcoming of the AZ31 magnesium alloy that is aimed to be controlled in this study by chemical conversion of its surface in various phosphate and chloride solutions. Deposited layers on the surface of bare alloy plates were subjected to compositional and morphological analyses to assess their performance as barriers to degradation. Also changes in the mass of the samples and pH of the solutions were monitored during 21 day immersion periods. Formations of prismatic, platelike, needlelike crystals of various compositions including calcium phosphates, magnesium phosphates, magnesium chlorides were observed by scanning electron microscopy and their atomic compositions were determined by EDX and quantitative XRD analyses. The results indicate that a layer of ceramic of various thicknesses can stably form on the base alloy by simple adsorption of the particles suspended in the solution or by nucleation and growth of the products of reactions between dissolved ions and the metal ions released from the surface. These deposition layers that are solely induced by the electrochemical potential of the species in the solution offer facile surface modification methods and novel phases to control the degradation of magnesium alloys in aggressive environments such as body fluids or marine environments.

Keywords

• AZ31 magnesium alloy
• Coating
• Magnesium phosphates
• Calcium phosphates
• Phase analysis.

Çeşitli Sulu Çözeltilerde Tutulan Magnezyum AZ31 Numunelerinin Yüzey Analizi

Abstract

Vücut ortamında hızlı bozunduğu bilinen AZ31 magnezyum alaşım yüzeyinin bu eksikliğinin çalışmamızda çeşitli fosfat ve klorür çözeltilerinde kimyasal dönüşüme maruz bırakılarak giderilmesi amaçlanmıştır. Alaşım plakaların yüzeyinde biriken katmanlar bozunmaya karşı bariyer performanslarını değerlendirmek için kimyasal ve morfolojik analizlere tabi tutulmuştur. Ayrıca numunelerin kütlesindeki ve çözeltilerin pH'ındaki değişiklikler 21 günlük daldırma süreleri boyunca izlenmiştir. Kalsiyum fosfatlar, magnezyum fosfatlar, magnezyum klorürler gibi çeşitli bileşimlerdeki prizmatik, plakamsı ve iğnemsi kristal oluşumları taramalı elektron mikroskobu ile incelenmiş ve bunların atomik bileşimleri EDX ve kantitatif XRD analizleri ile belirlenmiştir. Sonuçlar alaşım üzerinde çeşitli kalınlıklarda bir seramik tabakasının, basit adsorpsiyon ve çözünmüş iyonlar ile yüzeyden salınan metal iyonları arasındaki reaksiyon ürünlerinin çekirdeklenmesi ve büyümesi yoluyla kararlı bir şekilde oluşabildiğini göstermektedir. Yalnızca çözeltideki türlerin elektrokimyasal potansiyeli ile oluşan bu birikim katmanları, vücut sıvıları veya deniz ortamları gibi agresif ortamlarda magnezyum alaşımlarının bozunmasını kontrol etmek için sade bir yüzey modifikasyon yöntemi ve yeni fazlar sunmaktadır.

Keywords

• AZ31 magnezyum alaşımı
• Kaplama
• Magnezyum fosfatlar
• Kalsiyum fosfatlar
• Faz analizi.

References

1. [1] X. Li, X. Liu, S. Wu, K. W. K. Yeung, Y. Zheng, and P. K. Chu, “Design of magnesium alloys with controllable degradation for biomedical implants: From bulk to surface,” Acta Biomater., vol. 45, pp. 2–30, 2016.
2. [2] Z. Ran, W. Dai, K. Xie, and Y. Hao, “Advances of biodegradable magnesiumbased implants for orthopaedics,” Life Res., vol. 5, no. 7, pp.1-12, 2022.
3. [3] T. Cain, L. G. Bland, N. Birbilis, and J. R. Scully, “A compilation of corrosion potentials for magnesium alloys,” Corrosion, vol. 70, no. 10, pp. 1043–1051, 2014.
4. [4] F. Witte, V. Kaese, H. Haferkamp, E. Switzer, A. Meyer-Lindenberg, C.J. Wirth, and H. Windhagen, “In vivo corrosion of four magnesium alloys and the associated bone response,” Biomaterials, vol. 26, no. 17, pp. 3557–3563, 2005.
5. [5] F. Witte, N. Hort, C. Vogt, S. Cohen, K. U. Kainer, R. Willumeit, and F. Feyerabend, “Degradable biomaterials based on magnesium corrosion,” Curr. Opin. solid state Mater. Sci., vol. 12, no. 5–6, pp. 63–72, 2008.
6. [6] E. Ghali, “Magnesium and magnesium alloys,” Uhlig’s Corros. Handb., pp. 809–836, 2011.
7. [7] W. D. Müller, M. L. Nascimento, M. Zeddies, M. Córsico, L. M. Gassa, and M. A. F. L. de Mele, “Magnesium and its alloys as degradable biomaterials: corrosion studies using potentiodynamic and EIS electrochemical techniques,” Mater. Res., vol. 10, pp. 5–10, 2007.
8. [8] Y. Xin, K. Huo, H. Tao, G. Tang, and P. K. Chu, “Influence of aggressive ions on the degradation behavior of biomedical magnesium alloy in physiological environment,” Acta Biomater., vol. 4, no. 6, 2008.

9. [9] S. Seetharaman, D. Sankaranarayanan, and M. Gupta, “Magnesium-Based Temporary Implants: Potential, Current Status, Applications, and Challenges,” J. Funct. Biomater., vol. 14, no. 6, p. 324, 2023.
10. [10] A. Carangelo, A. Acquesta, and T. Monetta, “Durability of AZ31 magnesium biodegradable alloys polydopamine aided. Part 2: ageing in Hank’s solution,” J. Magnes. Alloy., vol. 7, no. 2, pp. 218–226, 2019.
11. [11] H. Hornberger, S. Virtanen, and A. R. Boccaccini, “Biomedical coatings on magnesium alloys–a review,” Acta Biomater., vol. 8, no. 7, pp. 2442–2455, 2012.
12. [12] Y. Wang, Z. Gu, J. Liu, J. Jiang, N. Yuan, J. Pu, and J. Ding., “An organic/inorganic composite multi-layer coating to improve the corrosion resistance of AZ31B Mg alloy,” Surf. Coatings Technol., vol. 360, pp. 276–284, 2019.
13. [13] Z. Q. Zhang, Y. X. Yang, J. A. Li, R. C. Zeng, and S. K. Guan, “Advances in coatings on magnesium alloys for cardiovascular stents–a review,” Bioact. Mater., vol. 6, no. 12, pp. 4729–4757, 2021.
14. [14] X. B. Chen, N. Birbilis, and T. B. Abbott, “Review of corrosion-resistant conversion coatings for magnesium and its alloys,” Corrosion, vol. 67, no. 3, pp. 35001–35005, 2011.
15. [15] Y. Song, S. Zhang, J. Li, C. Zhao, and X. Zhang, “Electrodeposition of Ca–P coatings on biodegradable Mg alloy: in vitro biomineralization behavior,” Acta Biomater., vol. 6, no. 5, pp. 1736–1742, 2010.
16. [16] J. H. Connor, W. E. Reid, and G. B. Wood, “Electrodeposition of metals from organic solutions: V. Electrodeposition of magnesium and magnesium alloys,” J. Electrochem. Soc., vol. 104, no. 1, p. 38, 1957.
17. [17] Q. Liu, D. Chen, and Z. Kang, “One-step electrodeposition process to fabricate corrosion-resistant superhydrophobic surface on magnesium alloy,” ACS Appl. Mater. Interfaces, vol. 7, no. 3, pp. 1859–1867, 2015.
18. [18] L. Staišiūnas, P. Miečinskas, K. Leinartas, A. Selskis, A. Grigucevičienė, and E. Juzeliūnas, “Sputter-deposited Mg–Al–Zn–Cr alloys–Electrochemical characterization of single films and multilayer protection of AZ31 magnesium alloy,” Corros. Sci., vol. 80, pp. 487–493, 2014.
19. [19] G. Bikulčius, P. Miečinskas, A. Ručinskienė, A. Grigucevičienė, A. Selskis, and V. Pakštas, “Improvement of corrosion resistance of magnesium alloy by sputter coating with stainless steel,” Trans. IMF, vol. 90, no. 3, pp. 125–128, 2012.
20. [20] A. R. Shashikala, R. Umarani, S. M. Mayanna, and A. K. Sharma, “Chemical conversion coatings on magnesium alloys-a comparative study,” Int. J. Electrochem. Sci., vol. 3, no. 9, pp. 993–1004, 2008.
21. [21] J. I. N. Hualan, Y. Xiangjie, and W. Ming, “Chemical conversion coating on AZ31B magnesium alloy and its corrosion tendency,” Acta Metall. Sin. (English Lett., vol. 22, no. 1, pp. 65–70, 2009.
22. [22] Y. Su, I. Cockerill, Y. Zheng, L. Tang, Y. X. Qin, and D. Zhu, “Biofunctionalization of metallic implants by calcium phosphate coatings,” Bioact. Mater., vol. 4, pp. 196–206, 2019.
23. [23] H. M. Wong, K. W. K. Yeung, K. O. Lam, V. Tam, P. K. Chu, K. D. K. Luk, and K. M. C. Cheung “A biodegradable polymer-based coating to control the performance of magnesium alloy orthopaedic implants,” Biomaterials, vol. 31, no. 8, pp. 2084–2096, 2010.
24. [24] P. Tong, Y. Sheng, R. Hou, M. Iqbal, L. Chen, and J. Li, “Recent progress on coatings of biomedical magnesium alloy,” Smart Mater. Med., vol. 3, pp. 104–116, 2022.
25. [25] L. Y. Li, L. Y. Cui, R. C. Zeng, S. Q. Li, X. B. Chen, and Y. Zheng., “Advances in functionalized polymer coatings on biodegradable magnesium alloys–A review,” Acta Biomater., vol. 79, pp. 23–36, 2018.
26. [26] Y. Chen, Z. Xu, C. Smith, and J. Sankar, “Recent advances on the development of magnesium alloys for biodegradable implants,” Acta Biomater., vol. 10, no. 11, pp. 4561–4573, 2014.
27. [27] E. Şahin and M. Çiftçioğlu, “Monetite promoting effect of citric acid on brushite cement setting kinetics,” Mater. Res. Innov., vol. 18, no. 3, pp. 138–145, 2014.
28. [28] E. Şahin, “Calcium phosphate bone cements,” in Cement Based Materials, London, United Kingdom, IntechOpen, 2018 vol. 191, pp. 191-219.
29. [29] E. V Musvoto, M. C. Wentzel, and G. A. Ekama, “Integrated chemical–physical processes modelling—II. simulating aeration treatment of anaerobic digester supernatants,” Water Res., vol. 34, no. 6, pp. 1868–1880, 2000.