LI Ximing CHEN Jiayong Institute of Chemical Metallurgy
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Academia Sinica
,
Beijing
,
ChinaR.KAMMEL Institut Für Metallurgie
,
Technische Universitt Berlin
,
Germany Research Assistant
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Institute of Chemical Metallurgy
,
Academia Sinica
,
Beijing 100080
,
China
金属学报(英文版)
The influence of mechanical activation on the leaching behaviour of scheelite was studied by means of fine grinding in an attritor and subsequently HCl leaching in presence of PO_4~(3-). Results showed that after fine grinding in the attritor,the reaction rate of scheelite with HCl-Na_3PO_4 solution was remarkably increased,the extraction of W increased from about 8 to 99%.The IR spectra and X-ray diffraction analysis indicated that in addition to an enlargement of surface area the fine grinding action had made also changes of fine struc- ture and reactivity of solid surface,hence the leaching process of scheelite can be carried out under mild leaching conditions.
关键词:
scheelite
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null
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null
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null
Song XIANG
,
Guoquan LIU
,
Yang LI
,
Changrong LI
,
ong WANG
,
null
,
null
,
null
,
null
,
null
材料科学技术（英文）
Microalloying element Nb in low carbon steels produced by compact strip production (CSP) process plays an important role in inhibiting recrystallization, decreasing the transformation temperature and grain refinement. With decreasing the rolling temperature, dislocations can be pinned by carbonitrides and the strength is increased. Based on the two sublattice model, with metal atom sublattice and interstitial atom sublattice, a thermodynamic model for carbonitride was established to calculate the equilibrium between matrix and carbonitride. In the steel produced by CSP, the calculation results showed that the starting temperature of precipitation of Ti and Nb are 1340℃ and 1040℃, respectively. In the range of 890-950℃, Nb rapidly precipitated. And the maximum of the atomic fraction of Nb in carbonitride was about 0.68. The morphologies and energy spectrum of the precipitates showed that (NbTi) (CN) precipitated near the dislocations. The experiment results show that Nb rapidly precipitated when the temperature was lower than 970℃, and the atomic fraction of Nb in carbonitride was about 60%-80%. The calculation results are in agreement with the experiment data. Therefore the thermodynamic model can be a useful assistant tool in the research on the precipitates in the low carbon steels produced by CSP.
关键词:
Compact strip production
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strip
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production
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niobium
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low
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car
Z. Yang
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J.P. Li
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J.X. Zhang
,
G.W.Lorimer
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J. Robson
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null
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null
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null
,
null
金属学报(英文版)
The current research and development of magnesium alloys is summarized. Several aspects of magnesium alloys are described: cast Mg alloy, wrought Mg alloy, and novel processing. The subjects are discussed individually and recommendations for further study are listed in the final section.
关键词:
Magnesium alloys
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null
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null
WADSWORTH Jeffrey and FLUSS Michael(Chemistry and Materials Science Directorate
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Lawrence Livermore National Laboratory
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Livermore
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CA 94551)
金属学报(英文版)
The role of the National Laboratories is summarized from the era of post World War II to the present time. The U.S. federal government policy for the National Laboratories and its influence on their materials science infrastructure is reviewed with respect to .determining overall research strategies, various initiatives to interact with industry (especially in recent years),building facilities that serve the nation, and developing leading edge research in the materials sciences. Despite reductions in support for research in the U.S. in recent years, and uncertainties regarding the specific policies for Research &Development (R&D) in the U.S., there are strong roles for materials research at the National Laboratories. These roles will be centered on the abilities of the National Laboratories to field multidisciplinary teams, the use of unique cutting edge facilities, a focus on areas of strength within each of the labs,increased teaming and partnerships, and the selection of motivated research areas. It is hoped that such teaming opportunities will include new alliances with China, in a manner similar, perhaps, to those recently achieved between the U.S. and other countries.
关键词:
: U.S. Materials Science. U.S. National Laboratories and Facilities
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null
Zheng FANG
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Quanru ZHANG
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Hengzhong ZHANG
,
Yuan FANG
材料科学技术（英文）
The thermoelectrochemistry (TEC), a novel cross discipline, is presented, including the basic equations for a cell and a half-cell reaction, the treatment of experimental data and its application to electro-generative leaching of mineral and to measuring thermodynamic and kinetic data of an electrode reaction. The TEC technology will play an important part in the research on the metallurgical process under various fields.
关键词:
新型炭材料
The uptake of hydrogen in carbon nanotubes is a hot topic in carbon nanotube research. Currently there are two methods to store hydrogen in carbon nanotubes. One is based on gas phase hydrogen storage and the other is based on an electrochemical method. Fundamental principles, theoretical calculations, and the interaction between hydrogen and carbon nanotubes for electrochemical hydrogen storage are reviewed. In particular, an overview of the most recent progress on electrochemical hydrogen storage in both single-walled carbon nanotubes and multi-walled carbon nanotubes is given and the prospect of their use in high performance batteries is highlighted.
关键词:
carbon nanotubes;electrochemistry;gas storage;nanofibers;adsorption
Huiguan WAN
,
Xiumei QI
,
Jing TIAN
,
Yuyong CHEN
,
Weiqiang ZHA
,
Jun JIA
材料科学技术（英文）
In this research, the materials and the compositions of the surface slurries were chosen by considering the characteristics of Ti investment casting. The effects of solid-liquid ratios on the properties of the slurry and the effects of baking temperatures on the flexural strength have also been investigated. Flawless shells having smooth inner surface were manufactured with proper technology. Ti and its alloys were melted and poured by water-cooled Cu crucible vacuum induction furnace. The qualities of the investment castings made accordingly were studied and analyzed.
关键词:
