J.Y. Zhang
,
Z.Y. Fu
,
W.M Wang
,
H. Wang and X.M. Min State Key Lab .of Advanced Technologyfor Materials Synthesis and Processing
,
Wuhan University of Technolo gy
,
Wuhan 430070
,
China
金属学报(英文版)
Self consistent Field discrete variational Xα( SCF Xα DV) method was used to study the wettabilitybetween TiB2 Ceramic and Metals. The Metals were Ni, Mo, Ni+ Mo, and etc. microstructureof TiB2/ Fe, TiB2/ Niand TiB2/ NiMoinvestigatedby TEM werechosen toidentify the calculation model. The result shows the wetting in the above systems were chemicalreactive wetting ,and can becalculated by SCF Xα DV . Theeffectof active ele ment( Mo) to TiB2/ Ni wettability wasstudied too.
关键词:
wetting
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null
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null
F.H. Froes(IMAP
,
University of Idaho
,
Moscow
,
ID 838443026
,
USA Manuscript received 26 August 1996)
金属学报(英文版)
The synthesis, processing and mechanical properties of the light metals, aluminum,magnesium and titanium Produced by advanced techniques are reviewed. Synthesis techniques to be addressed will include rapid solidification, spray deposition, mechanical alloying, plasma Processing and vapor deposition.
关键词:
:synthesis/processing
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null
,
null
,
null
,
null
,
null
,
null
,
null
,
null
,
null
,
null
Advanced Materials
Popularization of portable electronics and electric vehicles worldwide stimulates the development of energy storage devices, such as batteries and supercapacitors, toward higher power density and energy density, which significantly depends upon the advancement of new materials used in these devices. Moreover, energy storage materials play a key role in efficient, clean, and versatile use of energy, and are crucial for the exploitation of renewable energy. Therefore, energy storage materials cover a wide range of materials and have been receiving intensive attention from research and development to industrialization. In this Review, firstly a general introduction is given to several typical energy storage systems, including thermal, mechanical, electromagnetic, hydrogen, and electrochemical energy storage. Then the current status of high-performance hydrogen storage materials for on-board applications and electrochemical energy storage materials for lithium-ion batteries and supercapacitors is introduced in detail. The strategies for developing these advanced energy storage materials, including nanostructuring nano-/microcombination, hybridization, pore-structure control, configuration design, surface modification, and composition optimization, are discussed. Finally, the future trends and prospects in the development of advanced energy storage materials are highlighted.
关键词:
lithium-ion batteries;carbon nanotube electrodes;enhanced hydrogen;storage;metal-organic frameworks;double-layer capacitors;n-h system;carbide-derived carbons;ammonia borane dehydrogenation;ordered;mesoporous carbons;high-rate performance
Renbo SONG
,
Yazheng LIU
,
Tatsuhiko AIZAWA
材料科学技术（英文）
Thermoelectric materials, Mg2Si1-xGex(x=0, 0.2, 0.4, 0.6, 0.8, 1), have been prepared by bulk mechanical alloying (BMA) and hot pressing (HP). The electrical conductivity, Seebeck coefficient and thermal conductivity were measured from room temperature up to about 700 K. The electrical conductivity of all the samples increases with increasing temperature, while the Seebeck coefficient and thermal conductivity decrease with increasing temperature. Mg2Si and Mg2Si0.8Ge0.2 possess negative type of conductivity, while for other compounds it is positive. At the same time, the effect of hot processing condition on thermoelectric properties was also investigated. The maximum figure of merit of Mg2Si0.6Ge0.4 was obtained with the processing parameter of BMA at 600 cycles and hot pressing at 773 K and 1 GPa for 1 h.
关键词:
Solid-state synthesis
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null
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null
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null
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null
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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null
Materials Science and Engineering a-Structural Materials Properties Microstructure and Processing
A lot of non-equilibrium high technologies have recently been developed in materials processing, such as spray forming; metal atomization by electric fluid dynamics; self-propagating high temperature synthesis; in situ contact reaction process in melt for making composites and electropulsing effect on structure modification and damage reversal etc. A series of non-equilibrium thermophysical problems arise consequently with these high technologies. Not only the real-time measurements are difficult to deal with, but also the principle analyses need to be treated carefully. It would be found that some of the normal thermophysical rules should be evaluated again, when the thermophysical processes under extreme conditions are further studied. Some possible ways for solving these abnormal thermophysical problems are tentatively suggested in this paper, such as the reconstruction of governing functions; the simplified treatment of complex processes and making use of the rules of other disciplines etc. It is known from these examples that a series of non-equilibrium thermophysical problems arising from recent high technologies of materials processing are remained to be actively studied. It gives a virgin land for thermophysicists to explore. (C) 2000 Elsevier Science S.A. All rights reserved.
关键词:
biomimetic;materials processing;non-equilibrium;thermophysical;problems
D M DIMIDUK(Wright-Laboratory
,
Materials Directorate
,
WL/MLLM
,
Wright-Patterson AFB
,
OH45433-7817
,
USA)P R SUBRAMANIAN and M G MENDIRATTA (UES
,
Inc.
,
Dayton
,
OH 45432
,
USA)
金属学报(英文版)
Since the late 1980's there have been a number of research efforts aimed at exploring and developing the refractory intermetalllic materials for service at temperatures which compete with the nickel-based superalloys in structural applications. These efforts have documented the physical and mechanical properties of a broad set of compositions. However, only in the last three years have these efforts yielded sufficient experimental results on single selected systems to suggest that damage tolerance, creep resistance and oxidation resistance may be obtained and controlled simultaneously. These findings led to alloy development concepts and approaches which are currently under investigation and are expected to lead to research focused on a smaller set of alloys. An overview of selected alloy development strategies and resulting structural properties is presented herein.
关键词:
: refractory intermetallics
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null
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Materials Characterization
Segregation of yttrium induces the formation of Y0.25Zr0.75O2-x and Y0.5Zr0.5O2-y microdomains, with L1(2)- and L1(0)-like ordered structures, in ZrO2-6mol%Y2O3 ceramics in both the sintered and annealed states. The compositions of precipitates such as (chi L), (chi S), (chi SS), and small precipitates formed inside XL, in Cu-11.88Al-5.06Ni-1.63Mn-0.96Ti (wt.%) shape memory alloys have been determined. Under electron beam irradiation, four types of dynamic behavior of the G.P. zones were observed in the Al-6.58Zn-2.33Mg-2.40Cu (wt.%) alloy. The G.P. zone and "G.P. zone-like" defect structures were also distinguished. Lattice distortion profile in the GaAs/InxGa1-xAs superlattice and two-dimensional lattice distortion around a 60 degrees dislocation core in the InAs(x)P(1-)x/InP superlattice were determined. (C) Elsevier Science Inc., 2000. All rights reserved.
关键词:
shape-memory alloys;zirconia;phase;ti;diffraction;crystal
Express Polymer Letters
The state-of-art and key problems of carbon nanotube (CNT) based polymer composites (CNT/polymer composites) including CNT/polymer structural composites and CNT/polymer functional composites are reviewed. Based on the results reported up to now, CNTs can be an effective reinforcement for polymer matrices, and the tensile strength and elastic modulus of CNT/polymer composites can reach as high as 3600 MPa and 80 GPa, respectively. CNT/polymer composites are also promising functional composite materials with improved electrical and thermal conductivity, etc. Due to their multi-functional properties, CNT/polymer composites are expected to be used as low weight structural materials, optical devices, thermal interface materials, electric components, electromagnetic absorption materials, etc. However, the full potential of CNT/polymer composites still remains to be realized. A few key problems, such as how to prepare structure-controllable CNTs with high purity and consistently dependable high performance, how to break up entangled or bundled CNTs and then uniformly disperse and align them within a polymer matrix, how to improve the load transfer from matrix to CNT reinforcement, etc, still exist and need to be solved in order to realize the wide applications of these advanced composites.
关键词:
polymer composites;carbon nanotubes;mechanical properties;electrical;properties;thermal properties
