Abstract:The vertical semi-continuous casting method was applied to successfully prepare Cu-15Ni-8Sn alloy, the solidification structure, element segregation, the microstructure and properties after heat treatment were systematacially analysed. The casting structure of Cu-15Ni-8Sn alloy prepared by conventional casting consisted of Sn-depleted α-Cu(Ni, Sn) solid solution, Sn-rich γ phase, and lamellar (α+γ) structure, and the Sn element mainly segregated at grain boundaries. The grain refinement can be reached by vertical semicontinuous casting equipped with mechanical vibration (MV) and electromagnetic field (EMF) simultaneously, the Sn-rich γ phase distributed uniformly in grain interior and on grain boundaries, which reduces the degree of the inverse macro-segregation and micro-segregation at grain boundaries of Sn element. The optimal properties with a hardness of HV 401, an electrical conductivity of 8.4%IACS, an ultimate strength of 1233 MPa, a yield strength of 1185 MPa, and an elongation of 4.5% can be obtained in the sample after solution treatment at 850 °C, rolling treatment with 90% deformation and aging at 400 °C for 1 h.