The solidified microstructure of Ni-5% Cu alloy is researched at the cooling rate range of 13~130K/s with zone melting unidirectional solidification apparatus.It indicates that the crystals with different crystalline growth orientation have different solidified microstructures on the condition of
GL-1300 K/cm,
v=500μm/s.The crystals have different superfine cellular spacing due to the crystalline growth orientation with
GL=1300 K/cm,
v=800μm/s.The crystalline orientation has a great effect on the solidified microstructure in hyporapid solidification.