采用落管方法实现了Cu-20％Sb亚共晶合金在无容器条件下的快速凝固.随着液滴直径的减小,过冷度逐渐增大,初生Cu枝晶发生组织细化.实验中获得了207K的过冷度,最大过冷度达到0.17TL.理论分析表明,由于这一合金具有较宽的凝固温度间隔,初生Cu枝晶的快速生长始终受溶质扩散控制.根据对Cu-Sb合金相图中T0线的计算,揭示出发生无偏析凝固的临界过冷度为△T0=474K.在最大过冷度207K时,初生Cu相的生长速度达到37mm/s,发生了显著的溶质截留效应. The rapid solidification of Cu-20% Sb hypoeutectic alloy under vessel-free condition was achieved by drop-pipe method. The degree of undercooling gradually increased with the decrease of droplet diameter, Obtained 207K undercooling, the maximum undercooling reached 0.17TL. Theoretical analysis shows that due to the alloy with a wide range of freezing temperature, the rapid growth of primary Cu dendrites is always controlled by solute diffusion.Based on the Cu- Sb alloy phase diagram shows that the critical undercooling without segregation solidification is △ T0 = 474 K. The growth rate of the primary Cu phase reached 37 mm / s at the maximum undercooling degree of 207 K, and significant Solute retention effect.