Effects of Cu on microstructure and elevated temperature properties of as-cast Mg-Zn-Y alloy containing icosahedral quasicrystals phase were investigated. The results reveal that

with increasing in Cu content

microstructure of the MgZn

6

Y

1

alloy can be further refined. However

with Cu content more than 1. 5%（ in atom）

the grain size of alloy is coarsened. The addition of Cu can improve the elevated temperature mechanical properties of MgZn

6

Y

1

alloy. The tensile strength and elongation of MgZn

6

Y

1

Cu

1.5

alloy reach 153 MPa and10. 6%

compared with those of MgZn

6

Y

1

alloy

increased by 26. 4% and 49. 3%

respectively. The creep resistance of MgZn

6

Y

1

Cu

1.5

alloy is superior to that of MgZn

6

Y

1

under the same creep conditions.