from the conferences organized by TANGER Ltd.
<div>The aim of this work is to analyze the phase composition, microstructure, and thermal behavior of Sn-3.0Ag-0.5Cu solders with (0.1, 0.4, 1, 4) wt% Ni addition using experimental techniques (scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, differential scanning calorimetry) and computational thermodynamics (Thermo-Calc). The results show that the microstructure of all samples consisted of β-Sn dendrites in eutectic matrix (β-Sn + Ag3Sn) and elongated particles of Cu6Sn5 intermetallic phase. Ni is dissolved in Cu6Sn5 phase, and with an increasing amount of Ni, the Ni3Sn4 phase starts to form, at the expense of Cu6Sn5. With increasing Ni addition, the microstructure becomes coarser, mainly Cu6Sn5 and Ni3Sn4 phases with cracks observed mainly in the later phase. The low values of undercooling (3.6 14.4) °C of samples were determined, compared to the reported value for SAC305 solder. The results show a very good agreement between experimental results – phase composition, eutectic temperature, enthalpy of phase transformation (eutectic transformation + melting of β-Sn dendrites) and results achieved using thermodynamic computations in Thermo-Calc software.</div>
Keywords: Sn-Ag-Cu-Ni solders, microstructure, phase composition, thermal behavior, computational thermodynamics© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.