26.08.2015   An Introduction to Nuclear Materials

Elastic Interaction

This interaction takes place due to the mutual interaction of elastic stress fields surrounding misfitting solute atoms and the dislocation cores. The hardening effect related to the elastic interaction is directly proportional to the solute-lattice misfit. Substitutional atoms only obstruct the movement of edge dislocations. On the other hand, interstitial solutes impede both screw and edge dislocations.

2.4.1.1 Modulus Interaction

This occurs if the presence of a solute atom locally alters the modulus of the crystal.

If the solute has a smaller shear modulus than the matrix, the energy of the strain field of the dislocation will be reduced and there will be an attraction between the solute and the matrix. The modulus interaction is quite similar to the elastic inter­action, however, since it is accompanied by a change in the bulk modulus, both edge and screw dislocations will be subject to this interaction.