By metallographic microscope

scanning electron microscopy（SEM）

X-ray diffraction and other equipment and analysis

influences of Sn on microstructure and corrosion resistance of the as-cast Mg-2.7Nd-0.4Zn-0.5Zr-xSn were investigated.The results reveal that as-cast Mg-2.7Nd-0.4Zn-0.5ZrxSn（x=0.5

1.0

1.5

2.0）alloys are composed ofα-Mg matrix

Mg

12

Nd phase

particulate or rod-like Mg

2

Sn phase.With increasing in Sn content

Mg

2

Sn phase is increased gradually.The corrosion rate of as-cast alloy presents a trend of decreasing firstly and then increasing with Sn content increase.When Sn content is 1.0%

the alloy has the desirable corrosion resistance.The addition of Sn can refine Mg

12

Nd phase

and generate more stable Mg

2

Sn phase with more uniform distribution with 1.0%Sn content.