Influences of Sn on Fe phase segregation and properties of Cu-5Fe alloy

The Cu-5Fe-xSn alloy was prepared, and the effect of Sn on Fe phase distribution, precipitation kinetics, and properties of the Cu-5Fe alloy were investigated. The tensile strength and conductivity of Cu-5Fe-0.15Sn after aging at 400°C were 712 MPa and 66.6% IACS, respectively. Compared to the Cu-5Fe alloy, the tensile strength increased by about 190 MPa, while the conductivity decreased by only 1.4% IACS. Sn optimises Fe distribution and inhibits dendritic segregation. After drawing, the Fe phase is transformed into Fe fibre. Sn enhances the synergistic deformation ability of Cu/Fe, resulting in better continuity and density of Fe fibres. The precipitation activation energies of Fe in Cu-5Fe and Cu-5Fe-0.15Sn alloys were 95.9 and 84.9 kJ/mol, respectively. HIGHLIGHTS The addition of Sn significantly improves the mechanical properties of Cu-5Fe alloy. Sn addition optimised the primary Fe phase distribution and increased the Fe fibre density. The addition of Sn reduces the ultimate solid solubility of Fe in Cu and promotes the nucleation of γ-Fe phase. Sn reduces the activation energy of Fe phase and promotes the precipitation of Fe phase.