Effects of annular electromagnetic stirring processing parameters on semi-solid slurry production

A computational model coupling an electromagnetic model with a macroscopic heat and fluid flow model in semi-solid aluminum alloy slurry preparation by annular electromagnetic stirring (A-EMS) was developed. Effects of A-EMS processing parameters, such as stirring current, stirring frequency and stirring gap width, on macroscopic transport phenomena during the solidification were analyzed by commercial software ANSYS 10.0 with corresponding experimental verification. The results show that the magnetic flux density and the melt velocity increase and the temperature difference decreases as stirring gap width and stirring frequency decrease or the stirring current increases. The slurry with the fine and uniform globular grain structure can be gained by adjusting gap width, electromagnetic frequency and current, such as under the conditions of 10 mm of gap width,10 Hz of electromagnetic frequency and 50 A of current. The calculated results are in reasonably good agreement with the measured ones.