Considering the importance of the lead-free solders, alloys of ternary Bi-Sb-Zn system were characterized by microstructural SEM-EDS and optical microscopy analysis, Brinell hardness tests and electrical conductivity measurements. Isothermal cross section at 298 K was calculated using CALPHAD method and PANDAT 8.1 software package. The phases on calculated cross sections were found to be in a good agreement with experimentally determined phase compositions in analyzed microstructures.K e y w o r d s : Bi-Sb-Zn system, isothermal section, microstructure, Brinell hardness, electrical conductivity

Lead-free soldering has become very popular in the world recently, especially in electronics, because of high ecological demands in industry. Some of lead-free solder alloys are already used in electronic industry, but despite that investigations are still going in order to find suitable replacement for Pb-Sn standard solder. In this paper phase equilibria and characterization of Sn-In-Ag alloys in section In:Ag = 7:3 are investigated. The results of phase diagram calculation are obtained by ThermoCalc software, and characteristic temperatures by DSC method. The results of XRD analysis, optical microscopy, microhardness and electrical conductivity are also presented. These results are given in order to contribute the knowledge about lead-free solders, especially Sn-In-Ag solder alloys, which are potential candidates for replacement standard lead solders