材料期刊网

PHYSICAL MODELING FOR THE MECHANISMS OF BEAD FORMATION DEFECTS BASED ON THE STABILITY OF LIQUID METAL

S. Y. Yin , L. Feng , J. Z. Ding and S. J. Chan( 1) Beijing Polytechnic University , Beijing 100022 , China 2) National Key Laboratory of Advanced Wdlding Production Technology , HIT , Harbin 150001 , China)

金属学报(英文版)

Based on the theory of stability of the liquid metal under the action of surface tension,a physical mod- el is established for the mechanisms of the bead formation deferct' humping', which is generated during high - speed welding.A boundary function is introduced to correct the model,theoretical results got by the model correspond well with the experimental phenomena. A two - dimensional conducting model is adoopted in the simulation of the temperature field during high - speed welding.Finally, the factors acting upon the stability of liquid metal are analyzed.

关键词: high - speed welding , null , null

Key R&D activities for development of new types of wrought magnesium alloys in China

Transactions of Nonferrous Metals Society of China

Many researchers in China are actively engaged in the development of new types of wrought magnesium alloys with low cost or with high-performances and novel plastic processing technologies. The research activities are funded primarily through four government-supported programs: the Key Technologies R&D Program of China, the National Basic Research Program of China, the National High-tech R&D Program of China, and the National Natural Science Foundation of China. The key R&D activities for the development of new wrought magnesium alloys in China are reviewed, and typical properties of some new alloys are summarized. More attentions are paid to high-strength wrought magnesium alloys and high-plasticity wrought magnesium alloys. Some novel plastic processing technologies, emerging in recent years, which aim to control deformation texture and to improve plasticity and formability especially at room temperature, are also introduced.

关键词: wrought magnesium alloy;microstructure;properties;alloy designing;plastic deformation;research projects;y-zr alloys;mechanical-properties;mg-4y-4sm-0.5zr alloy;grain-refinement;rare-earth;microstructure;gd;phase;temperature;evolution

Recent Advances of Laser Coating Technology in China

LIANG Yong LI Ruiguo Institute of Metal Research , Academia Sinica , Shenyang 110015 , ChinaInstitute of Corrosion and Protection of Metals , Aademia Sinica , Shenyang , 110015 , China

材料科学技术（英文）

Recent advances in laser coating technology including laser cladding,laser surface alloying and laser vapour deposition in China are reviewed in this paper.

关键词: laser , null , null , null , null

THE CHANGING ROLE OF THE NATIONAL LABORATORIES IN MATERIALS RESEARCH

WADSWORTH Jeffrey and FLUSS Michael(Chemistry and Materials Science Directorate , Lawrence Livermore National Laboratory , Livermore , 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 , null

Change in Carbon Dioxide (CO2) Emissions From Energy Use in China′s Iron and Steel Industry

SUN Wenqiang , CAI Jiuju , MAO Hujun , GUAN Duojiao

钢铁研究学报(英文版)

As the largest energy consuming manufacturing sector and one of the most important sources of carbon dioxide (CO2) emissions, the China′s iron and steel industry has paid attention to the study of changing trend and influencing factors of CO2 emissions from energy use. The logarithmic mean Divisia index (LMDI) technique is used to decompose total change in CO2 emissions into four factors: emission factor effect, energy structure effect, energy consumption effect, and steel production effect. The results show that the steel production effect is the major factor which is responsible for the rise in CO2 emissions; whereas the energy consumption effect contributes most to the reduction in CO2 emissions. And the emission factor effect makes a weak negative contribution to the increase of CO2 emissions. To find out the detailed relationship between change in energy consumption or steel production and change in CO2 emissions, the correlation equations are also proposed.

关键词: CO2 emissions , energy use , LMDI technique , steel production , energy consumption

Titanium technology in the USA - an overview

D.Eylon , S.R.Seagle

材料科学技术（英文）

The state of Ti research, development and industry is reviewed in this article. The fifty-year anniversary of Ti technology commercialization in the USA provides an opportunity for a historical perspective. Incorporation of "information-age" tools into alloy development, processing, and production invigorates the technology. Consolidation, diversification and globalization have been transforming the Ti industry in the recent years.

关键词:

Advanced Materials for Energy Storage

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

Key Problems in Microforming Processes of Microparts

Chunju WANG , Debin SHAN , Bin GUO , Jian ZHOU , Lining SUN

材料科学技术（英文）

From the viewpoint of production engineering, microforming is considered as an effective process to fabricate various microparts. Several key problems in microforming processes were investigated. A new microforming apparatus with a high stiffness piezoelectric actuator as the punch driver was developed to produce microparts. To improve the forming abilities and locate the billets, a floating microdie was designed. The size effects of the billets and die cavities on the microforming abilities were studied with upsetting and coining tests, respectively. And the isothermal microforming process of microgears was performed with the developed microforming apparatus. Several analysis methods were used to evaluate the forming quality of the microparts.

关键词: Microforming , 尺寸效应 , 微塑性成形设备 , 浮动

R&D STATUS ON INTERMETALLICS IN CHINA

CHEN Guoliang(State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijing 100083 , China)SHI Changxu (Academia Sinica , Beijing 100864 , China)

金属学报(英文版)

This paper briefiy introduces the R&D of intermetallics in China. R&D on intermetallics in a national scale in China began near ten years ago. The investigation in past years focused on the fundamental research and materials development. A significant progress has been made. Various components that made of Ti3Al Ni3Al, TiAl and Fe3Al have been successfully manufactured Some of them have been evaluted. It is expected that some intermetallic alloys will be produced in an industrial scale in the near future.

关键词: :intermetallic alloys , null , null , null

Photoelectrocatalytic destruction of organics using TiO2 as photoanode with simultaneous production of H2O2 at the cathode

Applied Catalysis a-General

Research on the photoelectrocatalytic (PEC) oxidation of organic contaminants, the role of cathodes during photocatalysis has usually been disregarded. This paper reports a study of the PEC decomposition of aniline and salicylic acid with simultaneous production of hydrogen peroxide in a divided reactor using TiO2 as a photoanode. Two types of TiO2 electrode were used. Thermal oxidation electrodes (TO-TiO2) were made by oxidation of titanium metal sheet; sol-gel electrodes (SG-TiO2) were made by coating and then heating a layer of titania gel on titanium sheet. Saturated photocurrent was used to carry out an initial characterization and optimization of both electrode types. The best TO-TiO2 electrodes were prepared by heating titanium at 600-700 degrees C in air. For the SG-TiO2 electrodes, optimum performance was obtained by heating at 500 degrees C. These electrodes were then used to photodegrade aniline and salicylate. The SG-TiO2 electrodes turned out to be superior to the TO-TiO2 electrodes in terms of PEC rate under the same conditions but the difference in rate between the two electrodes was comparable under a high enough bias potential. The most important factors affecting the production of H2O2 in the cathode compartment are presented. The current efficiencies for the accumulation of H2O2 were remarkably affected by the cathode used, PH value, cur-rent density, and metal cations such as copper and iron ions. An expected H2O2 concentration could be obtained by controlling either the magnitude of the photocurrent or illumination time. The maximum current efficiency for the cathodic reduction of oxygen to H2O2 was as high as 90.1% when graphite was used as the cathode. Compared to the SG-TiO2 electrode, the TO-TiO2 electrode had a higher light to electricity conversion efficiency, thus it turned out to be more suitable for the production of H2O2. Furthermore, the role of in-situ reduced oxygen species in the PEC decomposition of aniline was evaluated. (c) 2005 Elsevier B.V. All rights reserved.

关键词: photoelectrocatalytic;thermal oxidation electrodes;sol-gel electrodes;titanium dioxide (TiO2);hydrogen peroxide production;ptfe o-2-fed cathode;thin-film electrode;titanium-dioxide;hydrogen-peroxide;photocatalytic production;suspended tio2;salicylic-acid;formic-acid;aniline;degradation