LIU Hefa SUN Naizhen DAI Xueli REN He Zhenjiang Shipbuilding Institute
,
Zhenjiang
,
Jiangsu
,
ChinaLI Lijun Shanghai
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Electrical Machinery Plant.Shanghai.China professor.Institute of Metallic Materials Research
,
Zhenjiang Shipbuilding Institute
,
Zhenjiang
,
Jiangsu 212003
,
China
金属学报(英文版)
Precipitation form of Zr in CuCoBeZr alloy during solidificotion.cooling and final aging,as well as its effect on the high temperature properties have been studied and discussed.Results show that during solidificotion and cooding.Zr precipitates as fine particle.Cu_3Zr,which pre- vents X-Cu grains from growing and provides more nuclei for CoBe and hence leads to finer primary CoBe.Fine Cu_3Zr partrticles also precipitate during aging. Because Co_3Zr is difficult to coalesce at high temperatures,the recrystallization temper- uture increases and the high temperature mechanical properties improve.
关键词:
CuCoBeZr alloy
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null
新型炭材料
The 2011 Annual World Conference on Carbon (Carbon 2011) was held in Shanghai, China, during 24-29 July, 2011. This conference was hosted jointly by East China University of Science and Technology, University of Shanghai for Science and Technology, and Institute of Coal Chemistry Chinese Academy of Sciences. About 800 attendees from 42 countries/regions participated in this conference, and 797 papers were accepted for presentation, including 5 plenary lectures, 42 keynote lectures, 280 oral presentations, and 470 posters, involving 10 topics: graphene; nanocarbon, carbon for energy storage and conversion, porous carbon and adsorption, carbon fiber and composites, precursor/carbonization and graphitization, computation and modeling, bio-carbon and safety, novel experimental techniques and characterization, bulk carbon and industrial applications. Research and development of nanocarbons are quite active and in particular, graphene received tremendous interest. Rapid progress has also been made on the electrochemical properties, energy conversion and energy storage applications of carbon materials.
关键词:
WADSWORTH Jeffrey and FLUSS Michael(Chemistry and Materials Science Directorate
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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
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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
Shaoxiong ZHOU
材料科学技术（英）
The discovery of the first Fe-based ferromagnetic amorphous alloy in 1966 had made an impact on conventional magnetic materials because of its unique properties. Since then, a number of amorphous magnetic materials have been successfully developed and used in a wide variety of applications. A brief review of R & D activities on amorphous soft magnetic materials in China is given from the beginning to the present in a somewhat chronological order, followed by a brief introduction to their applications on electric and electronic industries. An analysis and a prospect of Chinese market of such amorphous materials are also presented.
关键词:
Journal of Applied Physics
The dependence of yield strength, uniform elongation, and toughness on grain size in metallic structural materials was discussed. The toughness is defined as the product of yield strength and uniform elongation. The yield strength versus grain size can be well described by the Hall-Petch relation; however, the uniform elongation versus grain size is not well understood yet. A simple model involving the densities of geometrically necessary dislocations and statistically stored dislocations was proposed to estimate the uniform elongation versus grain size. Existing data for low carbon steels and aluminum indicate that, in the grain size less than 1 mu m, the materials usually exhibit high strength and low uniform elongation and, in the grain size greater than 10 mu m, the materials usually exhibit low strength and high elongation; in either case the toughness is low. However, in the grain size of several micrometers, the toughness is the highest. It is suggested that we should pay more attention to develop the metallic materials with grain size of several micrometers for structural applications. (c) 2007 American Institute of Physics.
关键词:
nanocrystalline copper;nanostructured metal;steels;deformation;ductility;law
Physical Review Letters
We find that the failure of bulk metallic glassy (BMG) materials follows three modes, i.e., shear fracture with a fracture plane significantly deviating from 45degrees to the loading direction, normal tensile fracture with a fracture plane perpendicular to the loading direction, or distensile fracture in a break or splitting mode with a fracture plane parallel to the loading direction. The actually occurring type of failure strongly depends on the applied loading mode and the microstructure of the material. Extensive evidence indicates that the Tresca fracture criterion is invalid, and for the first time, three fracture criteria are developed for isotropic materials with high strength, such as advanced BMGs or the newly developed bulk nanostructural materials.
关键词:
amorphous-alloys;enhanced plasticity;zr-ti;flow;deformation;composite;strength;microstructure;ribbons;failure
