Abstract
	The aim of the work was an experimental study of the copper – indium – tin ternary system, the purpose of which was to broaden the amount of the data published in the literature. The experimental work was performed at VŠB – Technical University of Ostrava. The experimental research of the reactive diffusion was performed in the selected Cu/Sn, Cu/Sn+In and Cu/In diffusion joints at various geometries of lay-out – plane dissolving, cylindrical dissolving and capillary tests - at different temperatures and time regimes. The samples were prepared from the metals of purities In – 5N, Sn – 5N and high-conductivity copper. The heat treatment of diffusion couples was performed in the laboratory furnaces at the following temperatures and time regimes: 400 °C/50 hours, 600 °C/48 hours and 600 °C/310 hours in the argon atmosphere or in vacuum. Having finished the annealing, the samples were quenched to water or freely cooled in the vacuum furnace. The following characteristics of samples were measured and studied: metallography, total chemical analysis (ICP-AES), spot and line chemical micro-analysis of individual phases in the structure of alloys (EDX, WDX). The program THERMOCALC (Masaryk University in Brno) and thermodynamic database COST 531 was used for thermodynamic calculations. CALPHAD (Calculation of Phase Diagrams) method, based on calculation of thermodynamic equilibria, was used for calculations of isothermal sections in the Cu–In–Sn ternary system at the temperatures of 600 and 400 °C. The obtained experimental results of the measured phase equilibria were compared with the thermodynamic calculations. The method of reactive diffusion provided representative results and identified reliably the present phases at simultaneous dissolving of the Cu matrix by the melt of solders Sn, In, and/or In+Sn. The copper and solder interaction was influenced by convection and high diffusivity in the melt, which resulted in a high speed of movement of the solid/liquid interface boundary.