医用镁合金微弧氧化涂层制备及降解行为研究进展

近年来,镁合金作为“可降解医用金属材料”越来越受到研究人员的青睐。然而,镁合金的腐蚀降解较快导致的力学衰减显著、材料与骨愈合的适配性减弱是当前限制其临床应用的瓶颈性问题。微弧氧化作为一种有效的减缓镁合金降解速率措施,具有工艺简单、成膜效率高、膜层整体综合性能优异等优点,实现了降解速度可调控与改善生物相容性双重功能。本文主要从微弧氧化（MAO）涂层形成机制及膜层降解机理出发,综述了生物医用镁合金微弧氧化涂层研究进展;详细阐述了微弧氧化涂层镁合金的膜层形成/破裂机制;系统地归纳了微弧氧化工艺参数和涂层降解性能、生物相容性的本质联系;揭示了自封孔型氧化膜的生长机制、封孔物质的沉积过程及其保留在微孔内的原因;概述了复合表面处理技术的膜层物相特征及仿生溶液环境下降解行为规律。最后,展望了医用镁合金微弧氧化涂层的未来发展方向。

Research Progress on Preparation and Degradation Behavior of Micro-arc Oxidation Coatings of Medical Magnesium Alloys

In recent years, magnesium alloy as a "degradable medical metal material" is more and more favored by researchers. However, the rapid corrosion degradation of magnesium alloys leads to significant mechanical attenuation and weakened suitability of the materials for bone healing, which is a bottleneck limiting its clinical application at present. As an effective measure to slow down the degradation rate of magnesium alloys, micro-arc oxidation has the advantages of simple process, high film forming efficiency and good overall performance index of the film, and realizes the dual functions of regulating the degradation rate and improving biocompatibility. The research progress of micro-arc oxidation coatings on biomedical magnesium alloys was reviewed. The essential relationship between micro-arc oxidation process parameters and biocompatibility of coating degradation performance was systematically summarized. The formation/rupture mechanism of micro-arc oxidation coating magnesium alloy was described in detail. The growth mechanism of the self-sealing porous oxide film the deposition process of the porous material and the reason of its retention in the micro-pores were revealed. The phase characteristics of composite surface treatment film and its degradation behavior in bionic solution environment were summarized. Finally, the future development direction of micro-arc oxidation coating for medical magnesium alloy was prospected.