부산대학교 도서관

Phase relationships in the Au-Co-Sn ternary system have been thermodynamically assessed by using the CALPHAD technique. The existing thermodynamic descriptions of the binary Au-Sn and Co-Sn systems were improved by incorporating the ab initio calculated enthalpies of formation of the intermetallic compounds including AuSn, CoSn, AuSn.sub.2, and AuSn.sub.4. For consistency, the Au-Co system was reassessed on the basis of the same pure element data as adopted for the Au-Sn and Co-Sn systems. With the combination of the three binary descriptions, the Au-Co-Sn ternary system was assessed by taking into account the ternary solubility in the binary compounds and the formation of a ternary compound. The obtained set of thermodynamic parameters can reproduce the measured phase equilibria at 380degC. The isothermal section at 396degC, the CoSn-Au and Au-SnCo vertical sections, and the liquidus projection were also calculated.