A Predicted Model for Activity Interaction Coefficient Between Solutes in Alloy Solutions

Activity interaction coefficients for solutes in alloy melts can be predicted by combining Miedema model with extrapolation models. However, the treatment of the binary interaction terms in traditional extrapolation models lacks a clear physical mechanism, which reduces the prediction reliability of models based on traditional extrapolation. The unified extrapolation model (UEM) can mathematically cover all traditional extrapolation models by introducing the contribution coefficient determined by property difference between two elements. In this study, a new model for activity interaction coefficients was built by using UEM to couple with the Miedema model and Tanaka excess entropy relation. The new model can explain the prediction characteristics and application scope of models based on traditional extrapolation in terms of the relation between the contribution coefficient and the property difference. The obtained results favorably agree with the experimental results.