Investigation on macrosegregation and dendrite morphology during directional solidification of Al-Cu hypereutectic alloys under a strong magnetic field

The effect of a strong magnetic field (up to 12T) on the macrosegregation and dendrite morphology during directional solidification of the Al-22at.%Cu alloy has been investigated. Experimental results show that the application of the magnetic field caused the freckle macrosegregation and the fracture of the Al2Cu dendrites during directional solidification. With the increase of the magnetic field, the size of the freckle and dendrite decreases. Moreover, the electron back-scatter diffraction (EBSD) was applied to study the effect of the magnetic field on the morphology and orientation of the Al2Cu dendrite. The EBSD results revealed that although the dendrites were destroyed under the magnetic field, the magnetic field did not yet change the orientation of the Al2Cu crystal. The formation of the freckles and the fracture of the dendrites under the magnetic field may be attributed to the TE magnetic effects. Copyright (C) EPLA, 2015