Simulation of atomic displacement cascades in the deformed HCP zirconium model by the molecular dynamics method. Evaluation of the effect of deformation on the defect structure

Background. The paper considers the influence of hydrostatic and uniaxial deformation of the HCP-Zirconium model crystallite on its defect structure formed as a result of the atomic displacement cascade passage with the energy of primary knock-on atom (PKA) 10 keV. The following axes were chosen for uniaxial deformation: $[23\: \overline{46}\: 23\: 27]$, $[\overline{1}\: 2\:\overline{1}\: 3]$, $[4\: \overline{5}\: 1\: 0]$, $[2\: 1\: \overline{3}\: 0]$. The compression and expansion ratio of the model crystallite amounted to 0.1, 0.5 and 1 %. Materials and methods. The study considers the HCP-Zirconium crystallite with hydrostatic and uniaxial deformation. A computer simulation was performed with the help of the molecular dynamics method using the many-body potential of interatomic interaction. Results. Numerical values of the point defects formation energy at the temperature of 0 K were obtained. The dependence of a number of surviving Frenkel pairs on the model crystallite deformation degree was not determined. The defects clustering analysis revealed the dominating single defects formation. Clusters of large size (>20 defects per cluster) were represented mainly by vacancies. Conclusions. The linear dependence of the formation energy on the model crystallite deformation degree was revealed. The defects clustering analysis revealed the dominating single defects formation. Clusters of large size (>20 defects per cluster) were represented mainly by vacancies. The largest defects clusters sizes were obtained in the deformed state, thus, the model crystallite deformation extended the formed clusters growth. The proportion of clustered vacancies was determined to exceed the proportion of self-interstitial atoms (SIA), and the average vacancy cluster size exceeded the average size of the SIA cluster.