Point defect dislocation interaction in a crystal under tension.

Abstract

The influence of an external uniaxial stress on the interaction between mobile efects and individual network dislocations is theoretically studied. The point defects are described within the lattice Green’s function formalism. Their interaction energy with a source of internal stress is deduced. This energy is calculated between intrinsic point defects and a dislocation in a strained f.c.c. crystal. The work aims at examining the foundations of the irradiation creep theory that explains the phenomenon as a preferential drift of interstitials and vacancies to dislocations with particular orientations to the external stress axis. The drift to edge dislocations is discussed using an expression that includes the discrete character of the jump. It is concluded that the proposed model of irradiation creep can only be sustained if the dipole tensors of the defects at the equilibrium and saddle point configurations fulfill some specific relations.