Research progress in corrosion resistance of biomedical magnesium alloys

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.