Evolution of atomic vacancy density during cyclic loading of single crystals of alpha-titanium

Abstract

Density evolution of atomic vacancies in α-titanium single crystals subjected to cyclic loading is numerically evaluated by using a crystal plasticity software code. Slip deformation is evaluated by dislocation density-based models and generation rate of atomic vacancies is given by the model proposed by Essmann and Mughrabi (1979). Parameters for dislocation movement, accumulation and annihilation are set so as that they mimic the dislocations' property in PSBs. Cyclic stress-strain curve, evolutions of SS dislocation density and atomic vacancy density are shown. It is obtained that atomic vacancy densities after 15 cycles of tensile/compressive loading of +/- 3 % reach 10²⁵ to 10²⁶ m^-3 , depending of the dislocation mean free path.