Dipartimento di Scienza dei Materiali e Ingegneria Chimica, Politecnico di Torino, Torino, Italy.
J Mater Sci Mater Med. 2010 Apr;21(4):1091-8. doi: 10.1007/s10856-009-3956-1. Epub 2009 Dec 18.
The successful applications of magnesium-based alloys as biodegradable orthopedic implants are mainly inhibited due to their high degradation rates in physiological environment. This study examines the bio-corrosion behaviour of Mg-2Zn-0.2X (X = Ca, Mn, Si) alloys in Ringer's physiological solution that simulates bodily fluids, and compares it with that of AZ91 magnesium alloy. Potentiodynamic polarization and electrochemical impedance spectroscopy results showed a better corrosion behaviour of AZ91 alloy with respect to Mg-2Zn-0.2Ca and Mg-2Zn-0.2Si alloys. On the contrary, enhanced corrosion resistance was observed for Mg-2Zn-0.2Mn alloy compared to the AZ91 one: Mg-2Zn-0.2Mn alloy exhibited a four-fold increase in the polarization resistance than AZ91 alloy after 168 h exposure to the Ringer's physiological solution. The improved corrosion behaviour of the Mg-2Zn-0.2Mn alloy with respect to the AZ91 one can be ascribed to enhanced protective properties of the Mg(OH)(2) surface layer. The present study suggests the Mg-2Zn-0.2Mn alloy as a promising candidate for its applications in degradable orthopedic implants, and is worthwhile to further investigate the in vivo corrosion behaviour as well as assessed the mechanical properties of this alloy.
镁基合金作为可生物降解的骨科植入物的成功应用主要受到其在生理环境中高降解率的限制。本研究考察了 Mg-2Zn-0.2X（X=Ca、Mn、Si）合金在模拟体液的林格氏生理溶液中的生物腐蚀性行为，并将其与 AZ91 镁合金进行了比较。动电位极化和电化学阻抗谱结果表明，AZ91 合金相对于 Mg-2Zn-0.2Ca 和 Mg-2Zn-0.2Si 合金具有更好的腐蚀行为。相反，与 AZ91 合金相比，Mg-2Zn-0.2Mn 合金表现出增强的耐腐蚀性：在 Ringer's 生理溶液中暴露 168 小时后，Mg-2Zn-0.2Mn 合金的极化电阻比 AZ91 合金增加了四倍。与 AZ91 合金相比，Mg-2Zn-0.2Mn 合金具有更好的腐蚀行为，这归因于 Mg(OH)(2)表面层的保护性能得到增强。本研究表明，Mg-2Zn-0.2Mn 合金有望成为可降解骨科植入物的候选材料，值得进一步研究其体内腐蚀行为以及评估该合金的力学性能。
