Low temperature softening of high-purity ultra-thin silver strip under large deformation

In this paper, low-temperature annealing was applied to soften high-purity ultra-thin silver strips subjected to large deformation. The mechanical and electrical properties of the softened silver strip were investigated using micro-Vickers hardness testing, electronic universal testing machines, and digital DC bridges. Microstructural evolution was characterized through the metallurgical microscope. The results demonstrate that low-temperature treatment (60-100°C) induces significant recrystallization in the heavily deformed silver matrix (>90% deformation), effectively replacing the elongated grain structure with equiaxed crystalline domains. This microstructural reconstruction stabilizes the material’s hardness within the HV 40-60 range and maintains consistent tensile strength while restoring electrical resistivity to 16.2 ± 0.2 μΩ·m. The observed macro-property stabilization directly correlates with the elimination of lattice defects and the formation of thermally stable grain boundaries through recrystallization processes. These findings establish the quantitative relationship between recrystallization-driven microstructural evolution and the corresponding macro-mechanical/electrical performance in ultra-thin silver strips.