Investigation of Microstructure, Electrical and Mechanical Properties of Zn-Mg-Sn High-Temperature Lead-Free Solder Alloy

In this study, the microstructure, electrical and mechanical properties of Zn-Mg-Sn alloy, a high-temperature lead-free solder material, were investigated. It was worked with 3 different compositions (Zn-3.5 at% Mg-x at% Sn (x = 2.5, 8.5(eutectic), 14.5)) of alloy. In particular, it was examined how the eutectic structure affects the investigated properties of the alloy in selected hypereutectic, eutectic and hypoeutectic compositions. At the same time, both cast and extruded forms of the compositions were obtained. Extrusion of the samples improved their mechanical properties and increased the melting temperature. In addition, it increased its electrical resistivity. Hardness values varied between 120 HV0.1 and 221 HV0.1 for cast compositions and between 130 HV0.1 and 228 HV0.1 for extruded ones. Max. Stress (σUTS) values changed in the range of 65.56 N/mm2 to 88.50 N/mm2 for cast compounds and in the range of 286.20 N/mm2 to 478.67 N/mm2 for extruded compounds. The highest value in melting temperature was obtained in the extruded composition (Zn–3.5 at% Mg–2.5 at% Sn) of the alloy. The resistivity of the eutectic composition (Zn–3.5 at% Mg–8.5 at% Sn) was found to be the smallest and its conductivity was found to be the largest.