Effects of Deformation and Recrystallization on Microstructure and Mechanical Properties of Cu–15Ni–8Sn–0.2Nb Alloy

The effects of cold deformation and subsequent recrystallization on the microstructure and mechanical properties of a Cu–15Ni–8Sn–0.2Nb alloy were systematically investigated. The results indicate that specimens subjected to a 35% reduction in area (R.A.) followed by recrystallization at 900 °C exhibit superior mechanical performance compared with those processed with 15% or 25% R.A. or recrystallized at 780 °C. The inferior properties at lower deformation levels are associated with limited stored energy, leading to a reduced driving force for recrystallization and insufficient grain refinement. Compared with samples recrystallized at 900 °C, those treated at 780 °C contain larger D0 3 (Ni 3 Sn) phases along grain boundaries, which act as stress concentration sites during tensile deformation, resulting in reduced elongation. These coarse phases also decrease the number density of strengthening precipitates in peak‐aged samples, deteriorating overall mechanical performance. Texture analysis shows that recrystallization at 900 °C eliminates the initial ⟨111⟩ texture and promotes a distinct RD ∥ ⟨101⟩ texture, which is absent at 780 °C. Under optimized conditions, the alloy achieves a tensile strength exceeding 1000 MPa with elongation above 25%.