生物医用镁合金表面改性涂层研究进展

镁合金凭借其优异的生物安全性、良好的载荷传递性及独特的降解性，在医用植入领域表现出巨大的应用潜力和发展前景。然而镁合金在生理环境下的腐蚀溶解速率过快，导致材料力学性能衰减加速进而过早失效。表面改性作为镁合金耐蚀性能提升的重要途径，不仅能通过表层物理屏障的形成来减缓金属材料的溶解速率，还能抑制合金内部腐蚀电偶反应的强烈程度及调控其生物相容性。概述了典型表面改性工艺的技术优势，包括涂层在合金表面的多覆盖度、高膜层厚度、强附着力以及良好生物相容性等。同时归纳了几种表面改性工艺所存在的问题，包括较差的长期耐蚀性、低应力承受能力以及技术安全性等。在此基础上，重点综述了近年来镁合金表面改性涂层的最新研究动态，其中简要介绍了化学转化、微弧氧化、等离子喷涂等几种常见的表面改性涂层形成机制。系统阐述了涂层对镁合金降解过程和生物相容性的影响规律，以及部分元素或粒子对涂层微观结构以及生物性能的作用机理。最后展望了医用镁合金表面改性涂层的发展方向。

Research Progress on Surface Modification Coatings of Biomedical Magnesium Alloys

Magnesium alloys have great application potential and development prospect in the field of medical implants, due to their excellent biosafety, good load-transfer and unique degradation behaviors. However, the corrosion dissolution rate of magnesium alloys was too fast under physiological environment, which leads to accelerated mechanical property decay and premature failure. As an important way to improve the corrosion resistance of magnesium alloys, surface modification can not only slow down the dissolution rate of metal materials through the formation of surface physical barrier, but also inhibit the intensity of corrosion galvanic reaction inside the alloy and regulate its biocompatibility. The technical advantages of typical surface modification processes were summarized, including multi-coverage, high film thickness, strong adhesion and good biocompatibility of coatings on the alloy surface. At the same time, the problems existing in several surface modification processes were summarized, including poor long-term corrosion resistance, low stress tolerance and technical safety. On this basis, the latest research trends of surface modification coatings on magnesium alloys in recent years were reviewed, and the formation mechanisms of several common surface modification coatings such as chemical transformation, micro-arc oxidation and plasma spraying were briefly introduced. The effects of coatings on the degradation process and biocompatibility of magnesium alloys and the mechanism of some elements or particles on the microstructure and biological properties of the coatings were systematically described. Finally, the future development of surface modified coatings on medical magnesium alloys was prospected.