The effects of single-polar rectangle wave pulse current on solidification structure of Al-Cu alloy have been observed. It was found that the pulse current can remarkably refine the solidification structure and primary phase in both eutectic Al-5Cu alloy and hypereutectic Al-50Cu alloy

which is attributed to wide frequency scope of the pulse current and low energy fading for high order of harmonic wave improving the useful work for solidification structure. Drift of magnetic field gradient and curvature of magnetic line generated from the heterogeneity of magnetic field resection can result in the migration of Al3+ and Cu+ in the alloy along the magnetic field direction with the pulse current treatment

promoting the oriented growth of primary phase CuAl2 along the magnetic filed direction.