Prediction of solid solubility in alloys

Abstract

A new empirical method for the analysis of solid solubility in alloys is proposed. The method is an extension of previous work by Darken and Gurry and by Chelikowsky. Each chemical element is characterized by three parameters: the atomic volume $V$, the electronegativity ${\phi }^{*}$, and the electron density at the boundary of bulk atomic cells $n_b.\Delta {\phi }^{*}$ and $\Delta n_b$ ($\Delta$ indicates the difference between solvent and solute) are combined into a unique parameter, $\Delta H_c$, the heat of formation of an equiatomic compound. This is done by using the semiempirical theory of Miedema and co-workers. Then, the two parameters $\Delta H_c$ and $\Delta V$ are used to construct a two-dimensional map. In this map, the chemical elements insoluble in a given host are neatly separated from the soluble ones. Even more, it seems that contours of increasing degree of solubility can be drawn with a fair degree of success.