Semiempirical Theory of Solid Solubility in Transition Metal Alloys

Abstract

A semiempirical theory of solid solubility in transition metal alloys is presented. The theory is based on writing the energy of formation of the solid solution as a sum of several contributions: a) a chemical contribution due to electronic redistribution in forming the alloy, b) an elastic contribution arising from the difference in size between solute and solvent atoms and c) a structural contribution due to the difference in crystal structure between solute and solvent and to the change in average valence when disolving foreign atoms. Special care is taken in evaluating these contributions in the concentrated alloy regime. The influence of charge transfer on the effective atomic volumes of the components in the alloy is also considered and found to be important. The results obtained are in good agreement with experiment.