MgZn

6x

Y

x

（x=0.7

1.0

1.5

2.0

atomic in%）alloys were prepared by conventional solidification technique.The effects of Y content on microstructure and mechanical properties of MgZn

6x

Y

x

alloys containing icosahedral quasicrystal phase（I-phase）as a secondary solidification phase were investigated.The results show that MgZn

6x

Y

x

alloys consist ofα-Mg matrix and（α-Mg+I-phase）eutectic structure which is distributed around the grain boundaries.With the increase of Y addition

the matrix grain size is decreased

and the content and the size of eutectic structure are increased

meanwhile the morphology of which also is transformed from discontinuous distribution to continuous distribution.During the solidification process

I-phase is formed undergoing eutectic reaction.Mg

89.5

Zn

9.0

Y

1.5

alloy exhibits the maximum ultimate tensile strength of 179.2 MPa and the maximum elongation of 3.5%

respectively.The fracture mode of MgZn

6x

Y

x

alloys is characterized by quasi-cleavage fracture.