ABSTRACT
The interaction of point defects with dislocations in the vicinity of the dislocation core determines many important features of dislocation behavior. This chapter presents a simplified treatment of the hybrid method in which a substitutional point defect in an isotropic, body-centered cubic crystal is represented by an array of forces applied to the nearest neighbor atoms only. The magnitude of the forces is determined by relating the volume change produced by the defect to the dipole strength of the array. The interaction energy of a spherically symmetric point defect with a screw dislocation in the isotropic elastic continuum approximation is identically zero. Anisotropic elastic solutions for the stress field of the dislocation yield a hydrostatic component, absent in the isotropic solution, whose magnitude depends on the degree of anisotropy. The far field expression for the lattice interaction vanishes identically, in agreement with the continuum model of the defect.
