生物医用镁合金耐腐蚀性能研究进展

Research progress in corrosion resistance of biomedical magnesium alloys

生物医用镁合金具有高比强度、低密度、合适的弹性模量、可降解性、良好的生物相容性及生物力学相容性等优点,在骨科固定和心血管支架等领域具有广泛的临床应用前景。然而,由于镁合金腐蚀过快和不均匀腐蚀等问题,易导致其过早丧失力学完整性,从而限制了其在承重部位的临床应用。本文从镁合金腐蚀类型、影响腐蚀性能的自身因素及外部因素、提高镁合金自身耐蚀性能及表面改性等方面系统综述了近年来的研究进展,并对生物镁合金耐蚀性能研究的未来发展趋势进行了展望:一方面,通过低合金化、高纯化及细晶化等手段改善镁合金自身耐腐蚀性能;另一方面,从耐蚀、抗菌及载药等方面着手设计可靠涂层;此外,研究镁合金植入器械的腐蚀降解行为及机理还需综合考虑腐蚀介质流场应力等体内服役因素。

Biomedical magnesium alloys exhibit high specific strength,low density,proper elastic modulus,biodegradability,good biocompatibility and biomechanical compatibility,thus show extensive application perspective in bone fixation and cardiovascular stent.However,fast and nonuniform corrosion of magnesium alloys may easily cause the premature loss of mechanical integrity that restricts their clinical application in load bearing.In this paper,the research progress of magnesium alloys was systematically reviewed from the aspects of corrosion modes,the intrinsic and external factors affecting corrosion resistance,improvement of intrinsic corrosion resistance and surface modification,and the future development trend of corrosion resistance of biomedical magnesium alloys was prospected.On the one hand,the corrosion resistance of magnesium alloys can be improved by means such as low alloying,high purification and fine crystallization.On the other hand,reliable coatings are designed from the aspects of corrosion resistance,antibacterial and drug loading.In addition,corrosion media,flow field,stress and other in-body service factors should be considered comprehensively to study the corrosion degradation behavior and mechanism of magnesium alloy implanted devices.