On the optimization of solution model parameter values of phases and the calculation of phase diagrams
Journal
Calphad
Journal Volume
17
Journal Issue
1
Pages
47-56
Date Issued
1993
Author(s)
Abstract
Phase equilibrium data are always used in addition to thermodynamic data in the optimization of model parameter values for all the phases in a binary or higher order system. The common strategy used to carry out the optimization is to compare the differences between the partial Gibbs energy values of the component elements at equilibrium. Three drawbacks inherent in this strategy are pointed out in the present study. An improved strategy is formulated to avoid these drawbacks. In the improved strategy, the objective functions used in the optimization are direct comparisons between the model-calculated compositions and/or temperatures of heterogeneous equilibria, and the experimentally determined values. The new strategy is used to optimize the model parameter values for all the phases and subsequent calculation of the phase diagrams for at least four binary and one ternary systems. These systems are Cu-In, Al-Zn, Al-Mg, Mg-Cu and Al-Mg-Cu. The new strategy is found to be much more powerful than the existing strategy. © 1993.
SDGs
Type
journal article