Generation of Atomic Vacancies by Dislocation Pair Annihilation

Density of atomic vacanciesAtomic vacancies increases rapidly during plastic deformation and these vacancies play roles in diverse aspects of the physical properties of metallic crystals. This chapter reviews a theory of the density evolution of atomic vacancies due to pair annihilation of dislocations during plastic slip deformation and proposes an extended model that is compatible with three-dimensional crystal plasticity analysis. Results of some numerical analysis are presented, and it is shown that the vacancy density is significantly high when slips on more than one slip systems occur. A possible modification to the model of critical resolved shear stress with increased density of atomic vacancies is presented.