G.Q. Zhang
金属学报(英文版)
The status of research, development of superalloys and materials processing & fabrication technologies for aero-engine applications in China Aviation Industry, with an emphasis on recent achievements at BIAM including directionally solidified and single crystal superalloys for blade and vane applications, wrought superalloys for aero-engine disks and rings, and powder metallurgy (PM) superalloys for high performance disk applications were described. It was also reviewed the development of new class of high temperature structural materials, such as structural intermetallics, and advanced material processing technologies including rapid solidification, spray forming and so on. The trends of research and development of the above mentioned superalloys and processing technologies are outlined. Cast, wrought and PM superalloys are the workhorse materials for the hot section of current aero-engines. New high temperature materials and advanced processing technologies have been and will be the subject of study. It is speculated that high performance, high purity and low cost superalloys and technologies will play key roles in aero-engines.
关键词:
superalloy
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null
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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
新型炭材料
The state-of-the-art research and development of various carbons for possible application as the electrode material in electrochemical capacitors (ECs) are summarized. The main factors affecting the properties of ECs are carefully reviewed, from the material characteristics such as specific surface area, pore size distribution and pore volume, surface functional groups and graphitic orientation of the carbon materials, to the electrode characteristics and electrochemical aspects such as electrode preparation process, electrode density and thickness, electrode conductivity and pseudo-capacitance, etc. In particular, an overview is given of the most recent progress in electrochemical capacitors using carbon nanotubes as the electrode material and the prospect of their use in this application is highlighted.
关键词:
electrochemical capacitors;carbon electrode;carbon nanotubes;double-layer capacitors;activated carbon;nanotube electrodes;supercapacitor electrodes;organic electrolyte;deposition;fiber
Acta Materialia
An analytical relationship between the ratio of hardness to reduced modulus H/E-r and the geometry of a residual indent is established based on the theories of depth-sensing indentation. Various material parameters, including elastic parameters, recovery deformation and energy-dissipation capacity, are uniquely determined by the value of H/E-r, so that they can be estimated from a residual indent trail. Thus, we are able to know what has happened in the material simply by analyzing or comparing residual trails on the material. The validity of this method has been confirmed by analyzing residual Vickers indents on quasi-plastic ceramic and brittle glass. In addition, it is demonstrated that the geometric constant epsilon in traditional nanoindentation theories is related to the proportional factor eta through the exponent of unloading curve m, i.e., epsilon = m (.) eta, where eta is defined by h(s) = eta (.) (h(m) - h(f)). (c) 2005 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
关键词:
residual indent;Vickers indenter;property prediction;H/E-r ratio;depth-sensing indentation;instrumented indentation;mechanical-properties;nanoindentation;modulus;hardness;deformation;films;load;substrate
Q.L.Deng1)
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W.D.Huang1)
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Y.H.Zhou1)
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C.Y.Yu2)
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Y.K.Zhang2)
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Y.X.Tang2) and H.Zhang2) 1) State Key Lab .of Solidification Processing
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Northwestern Polytechnical University
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Xi’an 710072
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China 2) Mechanical Department
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Nanjing University of Aeronautics & Astronautics
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Nanjing 210016
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China
金属学报(英文版)
The mechanism oflasershock processing wasanalyzedinthispaper. Westudyexperimentallythelasershock processingon 2024 T62 aviation aluminium alloys. Theexperimental results show thefatiguelife of 2024 T62 aviation aluminium alloysshocked by a laserisimprovedgreatly.
关键词:
lasershock processing
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null
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null
新型炭材料
Electrochemical capacitors (ECs) store energy in eletric double-layers formed along the interface of electrode material and electrolyte, this produces an extremely large capacitance compared with the traditional capacitors. The fundamental principles of electrochemical capacitors are briefly introduced, and the key materials used like electrode materials, electrolytes, separator and current collector materials are summarized. Electrochemical capacitors with pseudocapacitance, such as metal oxides, polymers and hybrid capacitors, are also discussed. The characteristics, possible application fields, the development state, the future R&D prospects for electrochemical capacitors are highlighted.
关键词:
electrochemical capacitors;supercapacitors;storage of electric energy;principles
J Y Wu
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Z.M. Tang
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W Shi andR.Z. Wang (Institute of Refrigeration and Cryogenics Engineering
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Shanghai Jiao Tong University
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Shanghai 200030
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China)
金属学报(英文版)
A transient method with rectangular pulse heating has been developed to measure the thermal conductivity of highly porous materials such as activated carbon, zeolite and silica gel. By this method the thermal conductivity can be measured quickly and accu-rately. In this paper, a set of automatically controlled testing equiptnent is presented.The measuring method is analysed. The thermal conductivities of some samples, such as activated carbon and zeolite, are measured by the equipment. A group of useful data has been obtained.
关键词:
thermal conductivity
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null
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