Molecular dynamics (MD) simulations are performed to investigate how ?3 (121) symmetric tilt grain boundary (GB) affects point defects and defect clusters in He-doped a-iron at 300 K in picosecond time scales. Molecular statics calculations are also performed and show that the formation energy is reduced in the GB, and the GB acts as a good sink for point defects especially for interstitial He and self-interstitial atoms (SIAs). It is observed that the average size of HenVm (m>n) clusters becomes smaller in the GB-containing Fe system. It is also found that the number of HenV (n=2, 3) clusters in the GB region decreases, while the number of the HeV clusters increases. The GBs loaded with substitutional or interstitial helium atoms are found to facilitate the growth of helium clusters in the GB region.
Revised: February 18, 2015 |
Published: August 1, 2014
Citation
Xu C.P., X. Liu, F. Gao, Y.H. Li, and Y.Q. Wang. 2014.Modeling radiation damage near grain boundary in helium-doped a-iron.Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms 332.PNNL-SA-101487.doi:10.1016/j.nimb.2014.02.111