The strain dependence of the solution energy of substitutional species is derived by expanding the binary alloy energy with respect to concentration and strain to the second order. Within the approximation of small strain and concentration inhomogeneities, the energy change is found to be proportional to the solute-induced stress, and the strain dependence of the solute energy is equivalent to that from the misfit model for solute atoms. However, the solute induced stress is easily calculated from first principles, and it is computed for Ag, Cu, Fe, Li, Mg, Mn, Si, and Zn atoms in aluminum. The results are used to estimate the solute-dislocation interaction energy. The enhancement of the solute concentration near a dislocation core and the role of dislocations on precipitation of these solutes are discussed.

• Received 27 June 2001

DOI:https://doi.org/10.1103/PhysRevB.64.224203