Thermophysical structure-sensitive properties of Tin–Zinc alloys

Tin–zinc-based alloys are under intense consideration as alternative lead-free solders for consumer electronics and telecommunications. This is because of their excellent creep resistance and fatigue resistance as well as mechanical and tensile properties. In present work, the thermophysical structure-sensitive properties of the Sn–Zn alloys prepared in the traditional bulk form, and in the foil form (30 µm thick and 6 mm wide) by the rapid solidification technique were studied and compared. The electrical conductivity study of Sn–Zn alloys from the Sn-rich side was carried out in the solid and liquid states in a wide temperature range from the room temperature up to 900 K. Thermal conductivity and viscosity were measured in the liquid state. The thermal conductivity results are consistent with the values calculated from the electrical conductivity data according to the Wiedemann–Franz–Lorenz law. The concentration dependence of viscosity revealed a negative deviation from the additive values. The melting-solidification region was studied by XRD and DSC. The behavior of thermophysical properties of Sn–Zn melts in the concentration range close to the eutectic composition indicates the existence of the micro-regions of remaining Zn phase in the temperature range above the melting temperature. The micro-inhomogeneous structure with the short range order in the Sn–Zn alloys after melting was confirmed by the structure analysis.