A new melt processing technology of spiral annular electromagnetic stirring（SA-EMS）was developed for understanding effects on solidification behavior of 7075 aluminium alloy

and effects of stirring current and pouring temperature on microstructures were analyzed.The SA-EMS process innovatively combined non-contact electromagnetic stirring and a spiral annular chamber with specially designed profiles to in-situ make high quality melt slurry

and intensive forced shearing could be achieved under high shears rate and high intensity of turbulence inside the spiral annular chamber.The temperature field

component field and tiny heterogeneous particles are distributed uniformly in the melt.The results indicate that the SA-EMS melt processing technology exhibits desirable grain refinement effects.With the increase of stirring current

the primaryα-Al particles are refined with more spherical.However

with the stirring current of 30 A

the change of solidification structure can be ignored.With the increaseof pouring temperature

the morphology of the primaryα-Al particle by SA-EMS is coarsened from globular to rosette-like and finally to dendritic.However

compared with conventional casting

importance of pouring temperature is weakened.