Abstract: This paper studies the effect of magnetic anisotropy of  α-Al single crystal on the dendritic morphology in Al-Cu hypoeutectic alloy under a static high magnetic field during directional solidification. Magnetic susceptibility of  α-Al single crystal slices with different crystal orientations are measured with the Faraday method. The results shows that the anisotropic and asymmetric magnetic property of the crystal cell of  α-Al containing Cu. The <111>-crystal direction is a hard magnetization direction while <311> or <310>-crystal direction is an easy magnetization direction. Magnetic susceptibility decreases with increase of Cu content in  α-Al. In addition, magnetic susceptibilities of the four crystal orientations among [111] are different. Besides, applying a 6 T longitudinal high magnetic field, the  α-Al dendrite deviates from the heat flow direction, which is parallel to the solidification direction without a magnetic field at a growth speed of 50 μm/s.This phenomenon may be attributed to the crystal magnetic anisotropy energy of  α-Al.

Key words: Al-Cu alloy, dendritic morphology, directional solidification, crystal magnetic anisotropy