Thermally diffused antimony and zinc coatings on magnesium alloys AZ31

Surface coating often alters or improves the performances of materials. In Mg alloys, surface treatment plays a key role in rendering them appropriate for widespread applications. Here, a thermal diffusion method of antimony and zinc is applied to deal with the surface of Mg alloys AZ31 in order to improve their functionalities. It is found that several compounds are newly generated in the coating layers, which, as a result, enhance the mechanical property and corrosion resistance considerably. By taking into account a variety of treatment temperatures and times, the sample treated by the mixed Sb and Zn powder at 753 K for 6 h is found to exhibit optimal comprehensive properties with a hardness of over 200 HV and the strongest corrosion resistance. This technique may be important for the technological improvement of surfaces of engineering Mg alloys.