Influences of different power（0

9

00 W）and treating time（0

1

20s）of ultrasonic on solidified structure and mechanical properties of Mg97Y2Cu1 alloy reinforced by long-period ordered structure were described.The results show that solidified structure and mechanical properties of the alloy can be improved by ultrasonic melt-treatment.The second phase is transformed from continuous network into uniform dispersion particles.With the increase of ultrasonic power or treating time

primary grain in the alloy is refined at first and then coarsened

and primary phase exhibits desirable with 700 Wfor 60 s.With the ultrasonic power of 700 Wfor 60s

tensile strength and elongation of the alloy are increased by23.8% and by 105%

respectively

compared with those of the alloy under traditional condition.