Effect of chemical composition and heat treatment on the microstructure and performance of Ag-based alloy wires

This study investigates the effect of Te addition combined with post-drawing heat treatment on the phase constitution, microstructure, microhardness, and corrosion behavior of Ag-based alloy wires. X-ray diffraction analysis revealed the formation of Ni 3 Sn 2 and Ag 2 Te intermetallic phases, while In was primarily dissolved in the matrix without the formation of detectable secondary phases. Optical microscopy and scanning electron microscopy observations showed that the as-drawn wires exhibited elongated grains and fibrous textures due to severe plastic deformation, accompanied by fine dispersions of second-phase particles. Heat treatment at 650 °C for 1 h facilitated static recrystallization, resulting in equiaxed grain structures and a redistribution of intermetallic phases. Energy dispersive X-ray spectroscopy analysis confirmed the presence of Ni 3 Sn 2 and Ag 2 Te phases. Microhardness measurements indicated an overall softening after heat treatment as a result of grain coarsening, although higher alloying levels provided moderate strengthening via solid solution and second-phase effects. Electrochemical testing demonstrated that increasing Sn, In, and Te contents reduced corrosion resistance, highlighting the trade-off between microhardness and corrosion performance. These findings provide insights for optimizing Ag-based alloys in applications requiring a balance between mechanical robustness and corrosion stability.