DOI: 10.3724/SP.J.1249.2017.05521

Journal of Shenzhen University Science and Engineering (深圳大学学报理工版) 2017/34:5 PP.521-525

Theoretical study of effects of grain boundaries on the radiation damage in iron and tungsten

This study is based on the chemical rate theory at steady state and the grain boundary sink effect. We find that the anti-irradiation ability of nano-crystalline materials is mainly determined by the vacancy diffusivity but barely by the absorption bias (the ratio of vacancy diffusivity to interstitial diffusivity). The anti-irradiation abilities of nano-crystalline iron and nano-crystalline tungsten are better than those of poly-crystalline. The behavior of radiation damage in nano-crystalline materials under non-equilibrium state is investigated by simulating the absorption capacity of grain boundaries on interstitials and vacancies by the molecular dynamics method. It is shown that the grain boundary has a good trapping ability for vacancies in iron. While for tungsten as a plasma facing material,more vacancies are retained in the bulk, mainly due to the effect of absorption bias. Under the typical service environment of fusion devices in the future, the level of absorption bias dominates the anti-irradiation ability of nano-crystalline materials before the steady state is reached.

Key words:plasma physics,nano-crystalline materials,radiation damage,steady state,anti-irradiation ability,molecular dynamics,grain boundary

ReleaseDate:2017-10-20 02:07:31

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