医用镁合金表面改性技术的研究现状

Research Status of Surface Modification Technology for Medical Magnesium Alloy

镁是机体代谢、骨骼组织组成的主要物质,也是酶促反应的必要补充因素,它能迅速通过血液的吸收和肾脏的代谢,在维护人体健康等方面发挥着重要的作用,具有强化骨骼强度、减少骨折风险、降血脂、抗动脉硬化等作用。但在生理学条件下,镁合金的腐蚀和溶解速度太快,会使材料的机械性能迅速下降,从而导致早期失效。所以,对镁合金进行表面处理是提高其耐腐蚀能力的一种重要手段。通过对金属表面进行改性,一方面可以保留其优良的物理性能,另一方面可以调节其耐腐蚀性能,从而达到控制降解的目的;同时,对植入体进行表面改性,可以调节其硬度,使其具有抗菌、促进骨生长及良好的生物相熔性。镁合金在医用植入领域表现出巨大的应用潜力和发展前景。但仍存在降解过快、生物相容性不足、力学性能不匹配等问题,所以本文又综述了几种表面改性的方法来解决问题,比如离子注入法、气相沉积、微弧氧化、复合涂层等技术。其中复合涂层的性能最佳并设计了在镁合金表面制备含有钙、磷的复合陶瓷膜层来提高镁合金的耐腐蚀性的实验。

Magnesium is the main substance of body metabolism,bone tissue composition and the necessary complementary factor of enzymatic reactions.It can be rapidly absorbed through the blood and metabolized by the kidneys.It plays an important role in maintaining human health,strengthening bone strength,reducing fracture risk,lowering blood lipids,and anti-atherosclerosis.However,under physiological conditions,the corrosion and dissolution rate of magnesium alloy is too fast,which will cause a rapid decline in the mechanical properties of the material,thus leading to early failure.Therefore,surface treatment of magnesium alloys is an important means to improve their corrosion resistance.Modifying the metal surface,on the one hand,can retain its excellent physical properties.On the other hand,it can regulate its corrosion resistance to control degradation;meanwhile,surface modification of implants can regulate its hardness so that it has antibacterial,promote bone growth and good biological phase fusion.Magnesium alloy in medical implants shows great potential for application and development.However,there are still problems such as too-fast degradation,insufficient biocompatibility,and mismatch of mechanical properties,so several surface modification methods are reviewed in this paper to solve the problem,such as ion implantation,vapor deposition,micro-arc oxidation,and composite coating techniques.Among them,the composite coating has the best performance and designed the experiments to prepare the composite ceramic film layer containing calcium and phosphorus on the surface of magnesium alloy to improve the corrosion resistance of magnesium alloy.