Effect of Nd-Rich Phases on the Corrosion Behavior of AZ80 Magnesium Alloy in Alkaline Solution

This work investigated the corrosion resistance of AZ80 (Mg-8Al-0.5Zn alloy) with different Nd contents in alkaline solution by the mass loss test, electrochemical test, scanning electron microscope, energy spectrum analysis, and x-ray diffraction. To remove the influence of the Mg17Al12 phase, alloys were heat treated at 410°C for 10 h. Results revealed that Al2Nd and AlMnNd phases mainly exist in the alloy. The corrosion rate of the alloy increased when the Nd content was < 0.4 wt.% because the Al2Nd phase formed galvanic corrosion with the Mg matrix. With the increase of Nd content, AlMnNd phase appeared in the alloys, which decomposed during the corrosion process and formed a good protective film to reduce the corrosion rate.