Modelling non-stoichiometric phases in the system Al-Cu-Mg-Zn

Thermodynamic databases for multicomponent systems are proving to be of great importance as a tool in materials design. Considerable effort is therefore being directed to the provision of more physically based and hence more reliable thermodynamic modelling of the different phases concerned. In this work a method illustrating the modelling of the non-stoichiometric T and Laves phases in the Al-Cu-Mg-Zn system is presented briefly, whereby the minimal information available is used to provide only a small number of parameters for formulation of the Gibbs energy of the phases.