Effect of a weak transverse magnetic field on the morphology and orientation of directionally solidified Al–Ni alloys

Abstract

The influence of a weak transverse magnetic field on the morphology and orientation of Al3Ni dendrites in directionally solidified Al-12wt% Ni alloys was investigated. The experimental results indicated that the magnetic field caused segregation. It was also found that the application of a magnetic field decreased the primary dendrite spacing. By means of electronic backscatter diffraction (EBSD) analysis, the orientation of the Al3Ni dendrite was studied. In the case of no magnetic field, the 〈010〉 crystal direction of the Al3Ni crystal was oriented along the solidification direction. When a transverse magnetic field was applied, the 〈001〉 crystal direction rotated to the magnetic field direction, whereas the 〈010〉 crystal direction remained oriented along the solidification direction. The above experimental results are discussed in the context of thermoelectric magnetic convection (TEMC) and crystal anisotropy.