Influence of thermoelectric effects on the solid–liquid interface shape and cellular morphology in the mushy zone during the directional solidification of Al–Cu alloys under a magnetic field

In this work thermoelectromagnetic convection (TEMC) is evaluated at different scales and the result shows that the effect of TEMC is different for different scales. To validate this analysis, Al–Cu hypoeutectic alloys were solidified directionally under a magnetic field, and both the interface shape and cellular morphology in the mushy zone investigated. The experimental results show that a weak magnetic field (B ⩽ 0.5 T) has a significant affect on the cellular liquid–solid interface and the cellular morphology. This is attributed to the TEMC caused by the interaction between the field and the thermoelectric (TE) current, which is consistent with the analysis. Under a higher magnetic field, the field causes the cells to break and makes the liquid–solid interface uneven; these effects are attributed to the magnetic force and the TE torque.