Semi-solid billets of Mg97Ni1Gd1Nd1 alloy were prepared by pulsed magnetic field refinement for solidification structure combined with subsequent low-temperature isothermal heat treatment.The results show that the refinement effect exhibits desirable with the pulsed voltage of 300 Vand pulsed frequency of 10 Hz

and the developed dendrite of Mg97Ni1Gd1Nd1 alloy is transformed into rosette equiaxed grains with average grain size from 650μm to about 80μm.The semi-solid billets with near-spheroidal primary phase can be obtained after treated by pulsed magnetic field below the melting point of primary-Mg and more than the melting point of eutectic structure.With treating at 560 ℃for 20 min

the spheroidizing structure in the semi-solid billets can be observed with the shape factor of 0.82.