With the help of the heat exchange between copper tube of the circulating cooling water and the electromagnetic stirred AZ91D metal to control the enthalpy equilibrium process of alloy melt

semi-solid slurry with thixotropic spherical structure for semi-solid rheoforming was prepared. The semisolid slurry was poured into the metal mold and by die casting

and electromagnetic stirring samples were observed comparatively in microstructure. The results indicate that the temperature of AZ91D alloy melt is decreased to liquid-solid two phase zone to form lots of primary α（Mg） nuclei and uniform distribution in the liquid metal under the condition of enthalpy equilibrium rotating electromagnetic device

which is responsible for the spherical and equiaxed grain in the metal and die casting samples.