Zinc alloyed coating on AZ91D magnesium alloys

In order to improve the corrosion resistance and micro-hardness of AZ91D magnesium alloys, its surface was treated by zinc alloys. The characterization of the above-prepared coating on AZ91D magnesium alloys was studied, and its surface image, cross-section image, XRD image, corrosion resistance ability and micro-hardness were also researched. The anodic polarization curve and electrochemical impedance spectrum of the coating on AZ91D magnesium alloys were examined before and after the samples being zinc alloyed. All results show that the zinc alloyed coating on AZ91D magnesium alloys is uniform and fine, and it is made up of Mg₇Zn₃, Mg and Zn. This coating has better corrosion resistance and good protective characterization than the magnesium alloys, and it has relatively higher micro-hardness than the magnesium alloys.