Experimental investigation and thermodynamic calculation of the Bi–Ga–Sn phase equilibria

Binary thermodynamic data, successfully used for phase diagram calculations of binary systems Bi–Ga, Bi–Sn, and Ga–Sn, were used for prediction of phase equilibria in ternary Bi–Ga–Sn system. The thermodynamic functions, such as enthalpy of formation and activity, were calculated using the Redlich–Kister–Muggianu model and compared with experimental data reported in the literature. The liquidus surface, invariant equilibria and three vertical sections with molar ratio Ga:Sn=1, Bi:Sn=1 and Bi:Ga=1 of the Bi–Ga–Sn ternary system were calculated by the CALPHAD method. Alloys, situated along three calculated vertical sections, were investigated by Differential Scanning Calorimetry (DSC). The experimentally determined phase transition temperatures were compared with calculation results and good mutual agreement was noticed.