Modeling Activity and Interaction Coefficients of Components of Multicomponent Alloy Melts: An Example of Iron Melt

Abstract

As a popular thermodynamic calculation method for binary alloys, Miedema's model has been applied in many fields. Chou's Model, a new generation of geometric model for ternary and multicomponent alloy systems, overcomes the intrinsic theoretical defects (including symmetric and asymmetric) existing in some original geometric models. Here, by means of combining Miedema's model and Chou's model as well as including the consideration of the excess entropy we attempted to build the new thermodynamic model to evaluate thermodynamic properties of ternary and multicomponent alloying systems in terms of the physical parameters (molar volume, electronegativity, electronic density and melting point) of constituents. Moreover, the activity and interaction coefficients of a wide of components in iron melt have been discussed in details.

Estimation of Activity Interaction Parameters in Fe-S-j Systems

“…After the Ding method, many prediction models have been established based on it. For example, Fan [ 15 ] coupled Chou’s geometric solution model with the Miedema model, Wang [ 16 ] applied Toop’s geometric model as extending method, Zhang [ 17 ] combined the Miedema model and Chou’s geometric solution model and also included excess entropy, etc. The prediction capability of the Ding method totally relies on the Miedema model.…”

“…Although many models based on the Ding’s method for activity interaction parameter calculations have been established, most of them have problems in use. The models coupled with Chou’s model [ 15 , 17 ], for instance, have the problem that the similarity coefficient is difficult to obtain. The models combined with the Toop/Toop-Kholer geometric model, such as Ding’s model [ 12 ] and Wang’s model [ 16 ], have mathematical difficulties in the deduction process when the solvent is chosen as an asymmetric component and one has to resort to other geometric models.…”