Microstructure evolution of cascade annealing in irradiated pure α-Zr: a molecular dynamics study

ABSTRACT

The microstructure evolutions of cascade annealing in α-Zr crystals at $T=300\mathrm{K}$, 400 K, and 500 K for energy of 2, 6 and 10 keV with initially driving directions $⟨0001⟩$ and $⟨01\overline{1}0⟩$ of the primary knocked atoms are investigated by using molecular dynamics simulations. The results show that the relaxation time (τ_r) of cascades can play the role of an effective parameter for describing radiation damages during molecular dynamics simulations. τ_r of cascade with the larger surface area but with the same volume is much smaller, which promotes faster recombination of defects during cascade annealing. Energy is a crucial factor in the formation of cascade displacements of atoms and appearing of defects compared with temperature and direction of movement for initially knocking atoms.

KEYWORDS:

• Pure α-Zr
• irradiation
• microstructure evolution
• cascade annealing
• molecular dynamics simulations

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work is supported by the National Nature Science Foundation of China (No. 51601185), the Defense Industrial Technology Development Program (No. JCKY2017201C016), the Sichuan Province International Science, Technology Cooperation, Exchanges Research Program (No. 2016HH0014), the China Postdoctoral Science Foundation (No. 2015M582575) and the National Key Research and Development Program of China (No. 2016YFB07001).