Abstract:Cu-Sn-P alloy has excellent strength and elastic properties, and can be used as the key basic material of connectors and connectors for precision instruments, aerospace and other high-tech fields.The hardening regulation, recrystallization structure evolution, and dynamic equation of high-performance ultra-fine grain structure Cu-Sn-P alloy strip during the preparation process are investigated,combing high deformation rate rolling, online continuous bright annealing technology and bending characteristics of different grain sizes.The results show that work hardening has a significant effect on the mechanical properties of Cu-Sn-P alloy and the higher the processing rate, the higher the strength and hardness of the alloy . The tensile strength of the alloy can reach 980MPa, when the working rate reaches 65%. The initial recrystallization temperature of Cu-Sn-P alloy is 350 ℃, and the higher the Sn content, the more obvious the work hardening effect. When the processing rate is 60%. Both an increase in recrystallization temperature and an extension of holding time may result the growth of recrystallized grain size. However, after the holding time reaches the critical value, the grain size no longer continues to grow with the extension of time. By combining high processing rate and online bright annealing, the grain size of high tin Cu-Sn-P alloy can refine to 4-6 μm. The grain boundary migration thermal activation energy can be expressed as Q=18.56 kJ·mol-1during the recrystallization process of Cu-Sn-P alloy at 450℃~550℃ insulation, and the kinetic equation for grain growth can be expressed as D=D02+5960.4te-2232/T.The R/T of ultrafine grain Cu-Sn-P alloy can be equal or lesser than 3, with no crack free on the surface，when the tensile strength is More than 900MPa.