Fabrication and Properties of Protective Metal Coatings Obtained by Surface Thermal Diffusion on Magnesium Alloys

Abstract

Magnesium alloy is a light-weight structural material.Applying this material in vehicles can reduce the vehicles’overall mass and energy consumption and improve their mobility and endurance.However,magnesium alloys are prone to corrosion,and their corrosion resistance needs to be enhanced.The surface diffusion method is a common surface strengthening method for magnesium alloys,in which the metal elements in the diffusion agent are transported to the surface of the magnesium alloy at a certain temperature and finally form a protective layer.Firstly,several common methods of surface diffusion on magnesium alloys were introduced in this paper.Secondly,the main influencing factors of thermal diffusion on the surface of magnesium alloys were summarized.Finally,the performance of the diffusion layer prepared by this method was introduced.The thickness of a typical diffusion layer formed by thermal diffusion on the surface of magnesium alloy could reach hundreds of microns,and the hardness and corrosion resistance of the diffusion layer were significantly improved compared with those of the substrate.Overall,surface thermal diffustion could effectively strengthen the surface of magnesium alloys.

Keywords

• magnesium alloy| thermal diffusion| pack cementation| diffusion metallizing| metal coating| surface protection