Substitutional solution hardening

Abstract Using the result of Stehle and Seeger for the volume expansion around a dislocation, the interaction of a screw dislocation with a substitutional impurity atom of different size from the solvent atoms is calculated. This result is then added to the interaction due to the different shear modulus of the solute atom. Yield strength measurements and shear modulus measurements have been made and, together with data from the literature allow comparison of the calculated relative effects of eleven different solute elements. The results imply that elastic interaction with screw dislocations controls the extent of solution hardening. Both atomic size and modulus contribute significantly to the hardening, but modulus difference supplies the dominant effect.