A thermodynamic assessment of the Bi-Mg-Sn ternary system

A complete thermodynamic description of the Bi-Mg-Sn ternary system was obtained by means of the CALPHAD (CALculation of PHAse Diagram) technique. The solution phases, Rhomb, Bct_A5 and Hcp_A3, are modeled with Redlich-Kister equation. The associate model has been used to describe the liquid phase with the constituents of the species Bi, Bi2Mg3, Mg, Mg2Sn and Sn. The non-stoichiometric compounds Mg2Sn and α-Bi2Mg3 as well as its high temperature variant β-Bi2Mg3 were described by the sublattice models (Bi,Mg)2(Bi,Sn)1, (Bi,Sn,Va)2Mg3 and (Bi,Sn)1(Bi,Sn,Va)3Mg6, respectively. The Bi-Mg-Sn ternary system has been modeled thermodynamically for the first time and the calculated phase equilibrium relations and thermochemical properties are consistent with the experimental results available in literatures.