The combination of atomic size and elastic modulus misfit interactions in solid solution hardening

Abstract

Solid solution hardening (SSH) is usually explained by atomic size and shear modulus differences between solute and solvent atoms. First, a new shear modulus misfit parameter ϵ GD is proposed, which is a modification of the Takeuchi parameter. Further, making use of the equivalence principle, a new combined interaction parameter ϵ E for the combination of atomic size and modulus misfit interactions with edge dislocations is derived. Finally, it is shown that literature data on SSH in the fcc metals Pb, Cu, Ag and Au well accounted for by the SSH theory of Labusch after substitution of the new modulus misfit parameter ϵ GD into the expression of the new combined interaction parameter ϵ E for edge dislocations. It is also shown that SSH in bcc iron, due to interactions with screw dislocations, is well accounted for by the SSH theory of Suzuki after substitution of the same modulus misfit parameter ϵ GD into one of Fleischer's combined interaction parameters.