CHEN Shu-ying
,
YUE Xu-dong
,
JIN Guang-can
,
LI Qing-chun
,
CHANG Guo-wei
钢铁研究学报(英文版)
The behavior of inclusions in the process of δ-phase growth during the solidification of Fe-015C-08Mn steel was in-situ observed using a high-temperature confocal scanning laser microscope (HTCSLM). The results show that inclusions arrive the S/L (solid/liquid) interface by way of direct impact or gradual drift, when the cell spacing is approximately equal to 177 μm during the growth of cellular δ-phase. The inclusions easily stay at the positions of trailing vortex formed by the circumferential motion of molten steel around δ-phase. Some inclusions reaching the S/L interface are captured by the solid-phase. Some of them move along the normal direction of the S/L interface because of pushing of solid-phase, and the others get away from the S/L interface after being pushed for a distance. The faster the growth rates of the solid-phase are, the easier the inclusions are captured by the S/L interface. The slower the growth rates of the solid-phase are, the easier the inclusions move with the S/L interface.
关键词:
inclusion
,
in-situ observation
,
carbon steel
,
solidification process
,
behavior
CHANG Guo-wei
,
CHEN Shu-ying
,
LI Qing-chun
,
YUE Xu-dong
,
JIN Guang-can
钢铁研究学报(英文版)
Abstract： Growth process of δ-phase was studied during the solidification of carbon steel. Through analyzing the solute diffusion around cylindrical crystals in the melt, the mathematic representation of lateral growth rate of cylindrical crystals was confirmed; the calculation and analysis of lateral growth rate were carried out. In order to validate the theoretical calculation and analysis, the growth process of δ-phase during the solidification was in-situ observed using a confocal scaning laser microscope (CSLM) and the growth rates were measured through CSLM images. The results show that lateral growth rates of δ-phase in the carbon steel first rapidly decrease with the increase of the radius of the cylindrical crystal, and then slowly fall down or maintain invariable. The radius of δ-phase is the primary factor to affect the growth rate. The higher the temperature gradient is, the bigger the growth rate is. However, the effect of the temperature gradient is feeble. Good correlation is obtained between theoretical analysis and experiment results in absolute values of lateral growth rate and change rule.
关键词:
Key words: cell growth
,
solidification process
,
carbon steel
,
in-situ observation
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
MANG Weishi WANG Guozhi ZHANG Yongchang HU Zhuangqi SHI Changxu Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
China Yongchang Associate Professor
,
Institute of Metal Research
,
Academia Sinica
,
Shenyang 110015
,
China
金属学报(英文版)
A rapidly solidified microcrystalline Al-Li-Cu-Mg-Zr alloy and its superplasicity have been investigated.An optimum tensile elongation of 585% was obtained at 540℃ and strain rate 1.67×10~(-2)s~(-1).The superplastic Al-Li alloy is manufaetured using thermomechanical pro- cessing:solution,overaging,warm rolling and recrystallization.Microstructural changes in thermomechanical processing and cavitation occurred during superplastic deformation have been observed.The superplastic failure of alloy may be caused mainly by nucleation and growth of cavities as well as the linkage around grains.
关键词:
superplasticity
,
null
,
null
,
null
Zhijian LIU
,
Zhiyou LI
,
Wei DUAN
,
Xuanhui QU
,
Baiyun HUANG
,
Siqi ZHANG
材料科学技术（英文）
A LI-B alloy has been prepared using a pretreated amorphous B powder and pure Li ingot as starting materials by continually slow addition of B powder and intensified stirring in the process of melting. The microstructure and the discharge characteristic of the materials have been investigated. Results show that the problem of temperature control in synthesis would be modified by means of continual addition of B powder, the Li7B6 would be more finery distributed in the metal Li by means of intensified stirring. The discharge characteristic of the Li-B alloy using amorphous B as starting materials is almost the same with that of using crystalline B.
关键词:
