Abstract
	The program COST Action 531 „Lead-free Solder Materials“ is focused on the basic scientific research of materials suitable for lead-free solders and on the problem of their practical application, reliability during long-term utilization in all types of equipment and  their recycling. The aim of the work was experimental study of the ternary system copper – indium – tin, the purpose of which was to broaden the amount of data published in the literature. The program THERMOCALC (Masaryk University in Brno) and thermodynamic database COST 531 was used for thermodynamic calculations. The experimental work was performed at VŠB – Technical University of Ostrava. The experimental research of the selected alloys of 82Cu2In16Sn, 82Cu12In6Sn, 30Cu35In35Sn, 15Cu80In5Sn, 65Cu30In5Sn, 76Cu11In13Sn, 66Cu20In14Sn, 55Cu40In5Sn, 40Cu50In10Sn was performed. The samples of alloys were prepared from the metals of the following purities: Cu – 4N5, In – 5N and Sn – 5N applying the process of melting in a graphite crucible at the temperature 1200 °C. The sample heat treatment in evacuated ampoules was performed in a laboratory furnace at the following temperature and time regimes: 200 °C – 56 days, 400 °C – 22 days and 600 °C – 7 days. Having finished the annealing, the samples were quenched to water.  The following characteristics of samples were measured and studied: the temperatures and enthalpy of the phase transformations (DTA, TG, DSC) of individual alloys at the rates of re-heating and cooling of 7°C/min, metallography and micro-hardness, total chemical analysis (ICP-AES), chemical micro-analysis of individual phases in the structure of alloys (EDAX, WDX). CALPHAD (Calculation of Phase Diagrams) method, based on calculation of thermodynamic equilibria, was used for calculations of the isothermal sections in the Cu–In–Sn ternary system at the temperatures of 600, 400 and 200 °C. The obtained experimental results of the measured phase equilibria were compared with the thermodynamic calculations.