The Cu-Sn phase diagram part II: New thermodynamic assessment

A thermodynamic description for the Cu-Sn system was developed using the CALPHAD approach taking into account all available literature data as well as the experimental results presented in Part I of this work. The higher order transformation from the disordered A2 phase to the ordered D0(3) phase has been described using the (Cu,Sn)(0.25)(Cu,Sn)(0.25)(Cu,Sn)(0.25)(Cu,Sn)(0.25) four-sublattice model for the first time. The calculated A2/D0(3) phase boundary is in good agreement with literature data. Additionally, the enthalpy of mixing of the liquid phase and the activity of Cu and Sn in the liquid alloys are well reproduced and enthalpies of formation of solid alloys and the activity of Sn in the (Cu) solid solution are calculated.