Subjects: Physics >> Condensed Matter: Structural, Mechanical and Thermal Properties submitted time 2017-03-26
Eryang Lu
Xingzhong Cao
Shuoxue Jin
Peng Zhang
Chunxiong Zhang
Jing Yang
Yaru Wu
Liping Guo
Baoyi Wang
Abstract：The evolution of microstruture for Fe16.7Cr14.5Ni model alloy and 316 stainless steel irradiated with 140 keV He ions were studied by Positron annihilation spectroscopy. The fluences were 1016 and 5016 He ions/cm2. The irradiation temperature was room temperature and 573 K, respectively. The variation of S parameter-incident positron energy profile indicated that large amount of vacancy-type defects formed after He ion irradiation. Meanwhile, helium atoms deposited in bulk and certain amount of He-vacancy complexes were formed. The vacancy-type defects could be the major defects in track region and He-vacancy complexes would be the main defects in cascade region. The vacancy-type defects could migrate and aggregate to form vacancy clusters and even microvoids at elevated temperature irradiation. The diffusion mechanism of helium atoms might be changed at different irradiation temperature.
Peer Review Status:
Awaiting Review
Subjects: Physics >> Condensed Matter: Structural, Mechanical and Thermal Properties submitted time 2017-03-24
Eryang Lu
Xingzhong Cao
Shuoxue Jin
Chunxiong Zhang
Peng Zhang
Liping Guo
Te Zhu
Yihao Gong
Baoyi Wang
Abstract：In order to study the microstructural evolution of the He+ irradiated FeCrNi model alloy, 140 keV He+ ions were implanted into the specimen with the fluence of 1015 ions/cm2 at room temperature. Positron Annihilation Spectroscopy was used to characterize the evolution of micro defects during isochronal annealing between 423 K and 873 K. The decrease of the S parameter between 573 K and 623 K has been associated to the annihilation of vacancy clusters, which were not trapped by helium atom. While the decline of the S parameter between 773 K and 823 K in the damage region might be caused by the dissociation of HenVm clusters. The dissociated vacancy clusters were unstable and annihilated rapidly, which decreases the concentration of vacancy defects.
Peer Review Status:Awaiting Review
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