镁合金表面腐蚀防护技术研究进展

镁合金较差的耐腐蚀性能限制了其大规模应用。利用表面腐蚀防护技术可以有效改善镁合金的耐蚀性能，延长镁合金的服役寿命。因此，可靠的表面腐蚀防护技术是突破镁合金应用瓶颈的关键。从镁合金表面腐蚀防护技术的分类入手，阐述了各种防护技术的基本原理。在此基础上，综述了近年来镁合金腐蚀防护技术的研究进展，包括电化学方法、化学方法及其他表面腐蚀防护方法等，阐明了各种技术的优缺点及适用范围，并对镁合金表面防护技术的发展趋势进行了展望。经过多年的发展，镁合金表面防护技术的理论研究和应用日臻完善，现有的表面防护方法一定程度上都能为镁合金基体提供腐蚀防护作用。然而，随着镁合金应用范围的扩展，相关结构件常会面临恶劣的服役环境。因此，单一的表面腐蚀防护技术已经很难满足工业领域对镁合金材料的迫切需求，多种表面处理技术联合制备的复合涂层具有广阔的应用前景。镁合金表面防护技术当前正朝着功能化和智能化的复合涂层方向发展，同时对制备工艺的安全环保性也提出了更高要求。未来除了保证高耐蚀性外，开发多功能智能涂层对提升防护层的长效防护能力、拓宽镁合金的应用范围具有重大的现实和长远意义。

Research Progress of Surface Corrosion Protection Technology for Mg Alloys

The relatively high corrosion susceptibility of Mg alloys seriously restricts their large-scale use. Surface corrosion protection technologies are used to improve the corrosion resistance and prolong the service life of Mg alloys. Hence, use of reliable surface corrosion protection coatings is the key to break through the bottleneck of Mg alloy application. Starting from the classification of surface corrosion protection technologies for Mg alloys, the basic principles of various protection technologies were expounded, and the advantages, disadvantages and application scope of various technologies were clarified. By comparing those surface corrosion protection technologies and introducing relevant research progress in China and abroad, the direction of future development was pointed out, which provided theoretical basis and technical support for the development of high-quality, multi-functional and anti-corrosive coatings for Mg alloys. The research progress of corrosion protection technology for Mg alloys in recent years is reviewed, including electrochemical methods, chemical methods and other surface corrosion protection methods. Among them, the inherent defects of chemical conversion, anodic oxidation and micro-arc oxidation lead to great loss of corrosion protection performance and durability, and these coatings are rarely used as the final protective layer. Electroless plating/electroplating process has high difficulty and cost in recovery of treatment solution and plating solution, and it is easy to react with Mg alloy substrate, resulting in loose coating structure, which affects the corrosion resistance. Laser treatment, particle injection, vapor deposition, spraying and other technologies require higher equipment and cost more. After years of development, the theoretical research and application of surface protection technologies for Mg alloys have been gradually perfected, and existing surface protection methods can provide corrosion protection for Mg alloys to a certain extent. However, with the expansion of Mg alloy applications, related structural parts face harsh service environments frequently. Therefore, single surface corrosion protection technology is difficult to satisfy the urgent demand for Mg alloys in the industrial field, and the composite coatings prepared by a combination of multiple surface treatment technologies have broad prospects. Nowadays, the surface protection technology of Mg alloys is developing in the direction of functional and intelligent composite coatings, and puts forward higher requirements in the safety and environmental protection of preparation process. In the future, in addition to ensuring high corrosion resistance, the development of multi-functional intelligent coatings is of great practical and long-term significance to improve the long-term protection of protective layer and broaden the application range of Mg alloys.