Numerical simulation of the casting process of an AZ91D magnesium alloy under a rotating-pulsed combined electromagnetic field

Using an AZ91D magnesium alloy as the research object, a three-dimensional (3D) numerical model was created and simulated using simulation analysis software. The effects of a rotating electromagnetic field (REMF), a pulsed electromagnetic field (PEMF) and a rotating pulsed electromagnetic field (R-PEMF) on the magnetic field and the flow field of a metal melt were investigated. The simulation results show that during the REMF treatment a rotational force is generated on the cross-section of the melt, and the PEMF exerts a magnetic pressure on the cross-section of the melt. Under the combined effect of these two forces, the Lorentz force increases parallel to the melt axis, and a secondary flow directed towards the core of the melt is generated, which contributes to the homogenization of the melt. By analyzing the solidification structure and elemental distribution of the metal, R-PEMF was shown to effectively improve the solidification structure and macrosegregation of Al in AZ91D magnesium alloy.