(1. State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, China) (2. Department of Materials Science and Engineering，Xi’an University of Technology, Xi’an 710048,China)
Magnesium (Mg) alloys are the lightest structural metal material with high strength-to-weight ratio, good thermal (electrical) conductivity and biocompatibility, having broad application prospects in automotive, aerospace, electronics and biomedical industries. As advanced light metals, Mg alloys are promising to replace the traditional materials, however, Mg is too reactive, and its native oxide scale is porous and cannot protect the base metal from environmental corrosion effectively. The low corrosion resistance has severely reduced the competitiveness of Mg alloys, and limits their applications. To this end, the surface protection of Mg alloys is indispensable. At present, there have been many kinds of surface treatment methods, but their protection effects are different. Here, we focus on the recent progress of two frequently used technologies, the chemical conversion and micro-arc oxidation. A new method based on the excited CO2 for surface modification of Mg alloys and the biomimetic superhydrophobic surfaces for corrosion protection of Mg alloys are introduced as well. In the end, we discuss the future direction of the surface protection of Mg alloys.