Abstract
Phase equilibria of the Ag-Sn-Cu ternary system have been determined experimentally as well as using the calculation of phase diagram (CALPHAD) method. Various Ag-Sn-Cu alloys were prepared to study the isothermal sections of the Ag-Sn-Cu ternary system at 240 and 450 °C. No ternary compounds were found and all the binary compounds had only limited ternary solubility. The ε 1 -Cu 3 Sn phase is a very stable phase. It is in equilibrium with the Ag, ζ-Ag 4 Sn, ε 2 -Ag 3 Sn, η-Cu 6 Sn 5 , and Cu phases at 240 °C, and is in equilibrium with the Ag, ζ, ε 2 , L, and δ-Cu 4 Sn phases at 450 °C. Thermodynamic models of the Ag-Sn-Cu ternary system were developed based on available thermodynamic models of the constituent binary systems without introducing ternary interaction parameters. The isothermal sections at 240 and 450 °C were calculated, and the results were in good agreement with those determined experimentally. In addition to the isothermal sections, stability diagrams of Sn and Cu were calculated as well. © 2004 Materials Research Society.