Critical evaluation and thermodynamic optimization of the Al-Ce, Al-Y, Al-Sc and Mg-Sc binary systems

New critical evaluations and optimizations of the Al-Ce, Al-Y, Al-Sc and Mg-Sc systems are presented. The Modified Quasichemical Model is used for the liquid phases which exhibit a high degree of short-range ordering. A number of solid solutions in the binary systems are modelled using the Compound Energy Formalism. All available and reliable experimental data such as enthalpies of mixing in liquid alloys, heats of formation of intermetallic phases, phase diagrams, etc. are reproduced within experimental error limits. It is shown that the Modified Quasichemical Model reproduces the partial enthalpy of mixing data in the liquid alloys better than the Bragg-Williams random mixing model which does not take short-range ordering into account.