Exceptional strength-ductility synergy of Ni and Co–Mg–La ferrite nanoparticles reinforced Sn-1Ag-0.5Cu matrix composite

Abstract

The use of innovative Co–Mg–La ferrite nanoparticles (ferrite) facilitates the production of superior Pb-free solder alloy materials that suffer from the strength-ductility trade-off (SDT). The current study introduces an original Pb-free Sn-1Ag-0.5Cu (SAC105) electrical connection alloy. It is fortified with cutting-edge ferrite and nickel providing a novel approach for improving SDT by avoiding early necking throughout different temperatures. The heterogeneous structures in Sn-1Ag-0.5Cu (SAC105) alloy are assembled by controlling a fraction of reinforcing ferrite and Ni, processed under cold-drawn and partial recrystallization. The optimal ferrite concentration in SAC105 composites is about 0.3 wt%, which possesses a significant strain hardening potential and the highest strength-ductility synergy. The excessive degree of heterogeneity of SAC105-0.3ferrite induces numerous strengthening mechanisms and dislocation accumulation, resulting in attaining high ultimate tensile strength (UTS) of 40.7 MPa with significant ductility of ∼47.7%, with ∼34.3% and 39% increasing when compared to SAC105. Once SAC105 solder was doped with 0.3 wt% ferrite or 0.05Ni with 0.3 wt% ferrite, the activation energy transferred from pipe diffusion to lattice diffusion. The solitary Ni addition, on the other hand, results in the SDT of plain SAC105.