Abstract:Beryllium bronze faces limitations in production and application due to high manufacturing costs, complex processing, and toxic dust. In contrast, Cu-15Ni-8Sn alloy has emerged as an ideal alternative material owing to excellent comprehensive properties. This study systematically investigated the influence of 0.8% （mass fraction） Zr addition on the microstructural evolution and mechanical properties of Cu-15Ni-8Sn alloy. Results demonstrated that the as-cast alloy exhibited a dendritic structure, primarily composed of α-Cu matrix, γ-CuNi2Sn phase, and skeletal/particulate Ni4SnZr phases. After solution treatment, the dendritic structure was eliminated, with the Ni4SnZr phase retained due to thermodynamic stability, while CuNi2Sn phase completely dissolved. Aging behavior studies revealed that the alloy's hardness initially increased and then decreased with aging time. The decline was primarily attributed to the formation of discontinuous precipitation. Moreover, higher aging temperatures accelerated discontinuous precipitation, leading to reduced peak hardness. Cold rolling significantly modulated microstructural evolution: a 78% cold deformation rate suppressed discontinuous precipitation while promoting the precipitation of ordered phases, achieving a peak hardness of 383HV after aging at 400 ℃ for 1 h. However, 90% deformation induced recrystallization softening, causing hardness to decrease to 378.5HV.