Effect of a high magnetic field on the Al–Al3Ni fiber eutectic during directional solidification

The effect of a high magnetic field on the morphology and preferred orientation relationship of the Al–Al3Ni fiber eutectic has been investigated during directional solidification. Results indicate that an application of a high magnetic field has decreased the eutectic spacing and caused the appearance of the band-like structure. Moreover, it has been found that a high magnetic field has changed the preferred orientation relationship of the Al–Al3Ni eutectic. Indeed, the application of a 12 T high magnetic field has caused the preferred orientation relationship of the Al{3 3 1}//Al3Ni{0 0 1}; Al [1 1 0]//Al3Ni[0 1 0] in the case of no magnetic field to transfer into the Al{0 0 1}//Al3Ni{1 0 2}; Al[1 0 2]// Al3Ni[0 1 0]. Further, in order to investigate the nucleation and growing mechanism of the Al–Al3Ni eutectic, the growth and morphology relationships between the Al–Al3Ni eutectic and the primary Al and Al3Ni phases have been investigated during volume and directional solidification, respectively. It has been found that the growth and orientation of the primary Al3Ni phase and the heating flow extraction direction have determined the growth of the Al–Al3Ni eutectic. This implies that the Al–Al3Ni eutectic growth may be capable of being controlled by adjusting the alignment of the Al3Ni eutectic phase and the heating flow extraction direction. The above experimental results have been discussed from the effect of a high magnetic field on the diffusion process and the epitaxial growth of the eutectic.