Search

Your search keyword '"Lei, Guanhong"' showing total 34 results
Start Over Author "Lei, Guanhong"
34 results on '"Lei, Guanhong"'

3. Ion-beam-assisted characterization of quinoline-insoluble particles in nuclear graphite

Author

Huang, Qing, Han, Xinqing, Liu, Peng, Li, Jianjian, Lei, Guanhong, and Li, Cheng

Subjects
Physics - Applied Physics
Abstract

The irradiation behavior of graphite is essential for its applications in nuclear industry. However, the differences between graphite's behaviors are not well understood because of the very limited knowledge of microstructural differences between graphites. One typical structure, quinoline insoluble (QI) particle, was investigated using IG-110 and NBG-18 graphite. After irradiation, the QI particles on the polished surface were proved to become hillocks and can be easily identified by using a scanning electron microscope (SEM). Thus a method combining ion irradiation and SEM characterization was proposed to study the distribution and concentration of QI particles in graphite. During irradiation, the QI particles were found to evolve into densified spheres which have weak bonding with the surrounding graphite structures, indicating that the densification of QI particles does not contribute obviously to graphite dimensional shrinkage. A much higher concentration of QI particles in NBG-18 than IG-110 was characterized and is suggested to be responsible for the smaller maximum dimensional shrinkage of NBG-18 than IG-110 during irradiation.

Published
2021
Full Text
View/download PDF

11. Saturation of ion irradiation effects in Cr2AlC

Author

Huang, Qing, Han, Han, Liu, Renduo, Lei, Guanhong, Yan, Long, and Zhou, Jie

Subjects
Condensed Matter - Materials Science
Abstract

Cr2AlC materials were irradiated with 7 MeV Xe26+ ions and 500 keV He2+ ions at room temperature. A structural transition with an increased c lattice parameter and a decreased a lattice parameter occurs after irradiation to doses above 1 dpa. Nevertheless, the modified structure is stable up to the dose of 5.2 dpa without obvious lattice disorder. The three samples irradiated to doses above 1 dpa have comparable lattice parameters and hardness values, suggesting a saturation of irradiation effects in Cr2AlC. The structural transition and irradiation effects saturation are ascribed to irradiation-induced antisite defects (CrAl and AlCr) and C interstitials, which is supported by the calculations of the formation energies of various defects in Cr2AlC. The irradiation-induced antisite defects and C interstitials may be critical to understand the excellent resistance to irradiation-induced amorphization of MAX phases., Comment: 14 pages, 8 figures

Published
2016
Full Text
View/download PDF

30. Structures and Hydrogen Storage Properties of La1-xMgxNi4.25Al0.75 (x=0.0, 0.1, 0.2, 0.3) Alloys

Author

Han Xingbo, Li Xiaolin, Cheng Honghui, Lei Guanhong, Tang Xiaoxing, Wang Cheng-Bin, Liu Wei, and Lü Lijun

Subjects
Materials science, Hydrogen, Alloy, Metallurgy, General Engineering, Analytical chemistry, chemistry.chemical_element, Induction furnace, 02 engineering and technology, Crystal structure, engineering.material, 010402 general chemistry, 021001 nanoscience & nanotechnology, Plateau (mathematics), 01 natural sciences, 0104 chemical sciences, Plateau pressure, Hydrogen storage, chemistry, Phase (matter), engineering, 0210 nano-technology
Abstract

La1-xMgxNi4.25Al0.75 (x=0.0, 0.1, 0.2, 0.3) hydrogen storage alloys were prepared by a three-step induction melting. Their crystal structures and hydrogen storage properties were investigated. Results show that alloys with x=0.0 and 0.1 contain a single LaNi4Al phase; however, those with x=0.2 and 0.3 are composed of LaNi4Al, (La, Mg)Ni3 and AlNi3 phases. With x increasing from 0.2 to 0.3, the abundances of the secondary phases and the plateau pressures in the pressure-composition isotherms are lifted significantly. Meanwhile, their hydrogen storage capacities are remarkably reduced. It is found that the alloy with x=0.1 possesses the fastest absorption kinetics compared to the others as well as a good hydrogen capacity and a low plateau pressure.

Published
2016
Full Text
View/download PDF

31. Effect of tellurium (Te4+) irradiation on microstructure and associated irradiation-induced hardening.

Author

Huang, Hefei, Liu, Jizhao, Lei, Guanhong, Muránsky, Ondrej, Wei, Tao, and Ionescu, Mihail

Subjects
TELLURIUM, ELECTRON probe microanalysis, DISLOCATION loops, TRANSMISSION electron microscopy, MICROSTRUCTURE
Abstract

The GH3535 alloy samples were irradiated using 15-MeV Te4+ ions at 650 °C to a dose of 0.5, 3.0, 10, and 20 dpa, respectively. The Te atoms distribution and microstructure evolution were examined by electron probe microanalysis (EPMA) and transmission electron microscopy (TEM). The nano-indenter was then used to measure the nano-hardness changes of samples before and after irradiation. TEM results showed the formation of dislocation loops in the irradiated samples. Their mean diameters increase with the increase of irradiation dose and tends to be saturated when irradiation dose exceeds 10 dpa. The ratio of yield strength increments calculated by dispersed barrier hardening (DBH) model is basically consistent with that of nano-hardness increments measured by nano-indenter. In addition, the relationship between the nano-hardness increments and dpa for the GH3535 alloy irradiated by Te ions has been revealed in the study. [ABSTRACT FROM AUTHOR]

Published
2021
Full Text
View/download PDF

32. Effects of FLiNaK infiltration on thermal expansion behavior of graphite

Author

Qi, Wei, primary, He, Zhoutong, additional, Tang, Hui, additional, Zhang, Baoliang, additional, Zhang, Can, additional, Gao, Lina, additional, Song, Jinliang, additional, Zhang, Dongsheng, additional, Wang, Xue, additional, Du, Xianlong, additional, Lei, Guanhong, additional, Xia, Huihao, additional, Wang, Jianqiang, additional, Huai, Ping, additional, and Zhou, Xingtai, additional

Published
2016
Full Text
View/download PDF

34. Effects of FLiNaK infiltration on thermal expansion behavior of graphite.

Author

Qi, Wei, He, Zhoutong, Tang, Hui, Zhang, Baoliang, Zhang, Can, Gao, Lina, Song, Jinliang, Zhang, Dongsheng, Wang, Xue, Du, Xianlong, Lei, Guanhong, Xia, Huihao, Wang, Jianqiang, Huai, Ping, and Zhou, Xingtai

Subjects
THERMAL expansion, GRAPHITE, CRYSTALLOGRAPHY, MELTING points, MOLTEN salt reactors
Abstract

The changes in both the crystallographic coefficient of thermal expansion (CCTE) and the coefficient of thermal expansion (CTE) of FLiNaK-infiltrated nuclear graphite were studied using in situ-heating X-ray diffraction analysis and horizontal push-rod dilatometry. It was found that, at temperatures lower than the melting point of FLiNaK, the CCTE of the d(002) spacing of graphite decreases with an increase in the weight of the graphite sample because of FLiNaK infiltration. On the other hand, the CTE of bulk graphite increases after molten salt infiltration. The CCTEs of the as-prepared FLiNaK salt, and the salt in the graphite pores were compared. The decrease in the CCTE of the FLiNaK salt after it had infiltrated into the graphite pores confirmed that interactions occur between the graphite and the salt. These interactions are probably induced by the difference in the CTEs of graphite and the solidified salt. Further, it is likely that the crystallization pressure also plays an important role here. Thus, both the causes need to be considered when using nuclear graphite in molten salt reactors. [ABSTRACT FROM AUTHOR]

Published
2017
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results