A crystallographically consistent optimization of the Zn–Fe system

Crystallographically based sublattice models have been constructed for all intermediate phases in the Zn–Fe system. The parameters of the models describing the Gibbs energies of these phases, as well as LIQUID, BCC, FCC and HCP substitutional solutions, were found by means of the CALPHAD technique. In comparison with the most recent model, the number of coefficients in the expressions for the excess Gibbs energies is significantly reduced. That decrease, however, is accompanied by a greater number of parameters needed in the expressions attributed to the Gibbs energies of end members. An advantage claimed for the present work lies in the models’ improved ability to predict which particular sublattice(s) will be capable of accommodating additional components. This property is of importance for the future extension to the Zn–Fe–Al system, and to other multicomponent systems of relevance to galvanizing and galvannealing practices.