Critical evaluation and thermodynamic modeling of the Al–Li binary system

Abstract

Al–Li alloys have extensive applications in aircraft and spacecraft due to their high mechanical performance and lightness in weight. In this work, the thermodynamic property and phase equilibria data of the Al–Li system available in the literature were critically reviewed and evaluated, thermodynamic assessments of the entire Al–Li system were then carried out based on the reliable experimental thermochemistry and phase equilibria data. The liquid phase was described using both the modified quasi-chemical model in pair approximation and the regular solution model. The compound energy formalism and the regular solution model were used to describe the Gibbs energies of the solid phases. The split four sublattice compound energy formalism was used to model the Gibbs free energies of the ordered AlLi (B32) and Al3Li (L12) superlattice structures. The reliable thermodynamic property and phase equilibria data can generally be represented by the currently obtained sets of self-consistent thermodynamic descriptions.