Effects of electromagnetic field on physical behaviors during low-frequency electromagnetic casting of Mg alloy AZ31

A numerical model was established for the simulation of the multiple physics fields during the low-frequency electromagnetic casting (LFEC) process of AZ31 alloy by using ANSYS (FE commercial package) and FLUENT (finite volume package). The electromagnetic field was calculated in the former and the latter was aimed at analyzing the fluid flow driven by magnetic, heat transfer and solidification. Overall physical parameters, including magnetic flux density, Lorentz force, flowing velocity, temperature field and liquid cave feature were discussed. Results show that the electromagnetic field can significantly affect the flow field and temperature field of the melt during the LFEC process of AZ31 alloy by inducing the effect of Lorentz force. Different electromagnetic frequencies have different effects. In the experimental frequency range of 5 ∼ 35 Hz, a higher frequency can intensify the flowing of the melt near the cooled wall of the crystallizer, resulting in an increase in heat transfer intensity and further a decrease in liquid cavity depth.