Yuxiong LU
,
Douxing LI
,
Dehai PING
,
Jing BI and Zongyi MA (Institute of Metal Research
,
Chinese Academy of Sciences
,
Shenyang 110015
,
China)
材料科学技术（英文）
The composite of Ti matrix with TiB whisker reinforcement has been successfully fabricated. The content of TiB whisker in Ti matrix can reach about 30 vol. pct. Metallographic examination,morphology and microstructure of TiB whisker, interface structure between TiB whisker and Ti matrix were investigated using optical microscope, SEM, TEM and HREM technology. The diameter distribution of TiB whisker is from 0. 1 μm to 3.5 μm and the aspect ratio of TiB whisker is from 10 to 20. The cross-section of whisker is generally polygon. Because of good compatibility between TiB whisler and Ti matrix it is identified that there is no obvious interaction of Ti matrix with Ti B reinforcement and TiB whisker reinforced Ti matrix composites have excellent elevated properties.
关键词:
Liping ZHENG
,
Shi QIU
,
Liping YU
,
Huyong ZHANG
,
Bingyao JING
,
Douxing LI
材料科学技术（英文）
The embedded atom method(EAM) is applied to calculate concentration distributions of Zr, Ni and Al at a Ni3Al-3 at. pct Zr grain boundary, and the Zr-induced distortion energies at the grain boundary, the bulk and the free surface. The calculated concentration distributions show that Zr segregation is present with Al-depletion and Ni-enrichment at the grain boundary. The reason might be that at the same zone, the Zr-induced distortion energy in the site of Al is always negative and lower than that of Ni, and that the Zr-induced distortion energy in the Al site at the grain boundary is the lowest among those at all zones.
关键词:
Zhiquan LIU
,
Douxing LI
,
Xiaolei XU
,
Liang WANG
,
Zukun HEI
材料科学技术（英文）
Two body centered tetragonal (bct) crystal structures of alpha"-Fe16N2 with x=0.25, z=0.3125 (Jack-1) and x=0.222, z=0.306 (Jack-2) respectively, were analyzed theoretically with EMS software package. The simulation of diffraction patterns indicates that both diffraction patterns of the same axis in these two structures obey bcc extinction rule. The conclusion is also obtained from the analyses of the diffracted waves. alpha"-Fe16N2 precipitates in the diffusion layer of ion-nitrided alpha-iron have been studied with transmission electron microscope (TEM). We have distinctly observed the electron diffraction patterns of alpha"-Fe16N2 in [100], [111], [110], [011], [210], [021], [311], [113], [331] and [133] zone axes with perfect symmetry, which indicate the parallel orientation relationship with alpha matrix: <001>(alpha")//<001>(alpha), {100}(alpha")// {100}(alpha). The analyses of diffraction patterns, which obey bcc extinction rule, verify the bet structure of alpha"-Fe16N2 discovered by X-ray diffraction.
关键词:
Jiancun RAO
,
Yu ZHOU
,
Douxing LI
材料科学技术（英文）
A new type of long periodic structure has been found in ZrO2-Y2O3 ceramics in annealed states. High resolution electron microscopy (HREM), selected area electron diffraction, and computer simulation have been used to reveal the presence of the long periodic structure. The unit cell of the long periodic structure consists of a cubic ZrO2 unit cell and L10- like phase one.
关键词:
Ceramics
,
null
,
null
,
null
,
null
李志宏
,
柳卫平
,
白希祥
,
郭冰
,
连钢
,
颜胜权
,
王宝祥
,
陆昀
,
曾晟
,
苏俊
原子核物理评论
doi:10.3969/j.issn.1007-4627.2005.01.006
利用8Li次级束测量了质心系能量7.8 MeV 2H(8Li, 9Li)1H反应的角分布, 导出了8Li(d, p)9Li反应的天体物理S因子及9Li→8Li+n虚衰变的渐近归一化系数.
关键词:
8Li(d,p)9Li反应
,
角分布
,
天体物理S因子
,
渐近归一化系数
HUANG Jianshun CHEN Junming Shanghai Institute of Metallurgy
,
Academia Sinica
,
Shanghai
,
China Research Associate
,
Shanghai Institute of Metallurgy
,
Academia Sinica
,
Shanghai 200050
,
China
金属学报(英文版)
Crystal structure of γ-Li_xFe_2O_3,inserted Li electrochemically,was studied by Moss- bauer spectroscopy together with X-ray diffraction,XPS and electrochemical method,On the insertion of Li at low current density,the crystal structure is keeping original spinel; while at higher current density or by thermal activation,owing to violent movement of Li~+ ions,part of crystal structure transforms into rock type similar to face-centered cubic structure of ferrous oxide.The transition channels during insertion of Li~+ ions and limitation of Li~+ ions inserted were discussed.
关键词:
null
,
null
,
null
Journal of Materials Research
The effect of Li(3)N additive on the Li-Mg-N-H system was examined with respect to the reversible dehydrogenation performance. Screening Study with varying Li(3)N additions (5, 10, 20, and 30 mol%) demonstrates that all are effective for improving the hydrogen desorption capacity. Optimally, incorporation of 10 mol% Li(3)N improves the practical capacity from 3.9 wt% to approximately 4.7 wt% hydrogen at 200 degrees C, which drives the dehydrogenation reaction toward completion. Moreover, the capacity enhancement persists well over 10 de-/rehydrogenation cycles. Systematic x-ray diffraction examinations indicate that Li(3)N additive transforms into LiNH(2) and LiH phases and remains during hydrogen cycling. Combined structure/property investigations suggest that the LiNH(2) "seeding" should be responsible for the capacity enhancement, which reduces the kinetic barrier associated with the nucleation of intermediate LiNH(2). In addition, the concurrent incorporation of LiH is effective for mitigating the ammonia release.
关键词:
complex hydrides;improvement;mixtures;imides;amide;h-2
