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XPS Studies of Magnetic Multilayers

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Journal of University of Science and technology beijing 2001年第3期8卷 210-213页

作者： Guanghua Yu, Hongchen Zhao, Jiao Teng, Chunlin Chai, Fengwu Zhu, Yang Xia, Shumin Chai material Science and Engineering School, University of Science and technology beijing, beijing 100083, China microelectronics Center, Chinese Academy of Science, Beijin Univ Sci & technol beijing Sch Mat Sci & Engn Beijing 100083 Peoples R China Chinese Acad Sci Ctr Microelect Beijing 100029 Peoples R China

NiOx/Ni81Fe19 and co/AlOx/co magnetic multilayers were fabricated by reactive RF/DC magnetron sputtering on clean glass substrates and oxidized Si (100) substrates, respectively. The exchange biasing field (H-ex) between NiO4 and Ni81Fe19 as a function of NiOx oxidation states was studied by X-ray photoelectron spectroscopy (XPS). The oxidation states and the oxide thickness of Al layers in magnetic multilayer films consisting of co/AlOx/co were also analyzed. It is found that the H-sr of NiOx/Ni81Fe19 films only depends on Ni2+ but not on Ni3+ or Ni. The bottom co can be completely covered by depositing an A I layer thicker than 2.0 nm. The oxide layer was Al2O3, and its thickness was 1.15 mn.

关键词： NiOx exchange biasing field H-ex AlOx X-ray photoelectron spectroscopy (XPS)

A Study of Grain Growth Kinetics in Sintered NdFeB Magnets

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Journal of Rare Earths 2001年第3期19卷 209-213页

作者：刘湘涟何建平董清飞周寿增 Univ Sci & technol beijing State Key Lab Adv Met & Mat Beijing 100083 Peoples R China beijing Hengei technol co Ltd Beijing 100080 Peoples R China

The Nd2Fe14 B grain growth kinetics in sintered NdFeB magnets with nominal compositions of Nd30+xDy1.5Fe67.08-xAl0.4B1.02 (%, x = 0, 3) was studied. The grain size parameters were determined by means of the linear intercept method on SEM secondary electron images. It is observed that the grain growth process is more sensitive to sintering temperature than to sintering time although the grain size rises with both sintering temperature and time. It is also found that magnets prepared from the pre-alloy powder with a higher oxygen content exhibit a lower grain growth rate and magnets made from the pre-alloy powder with a broader particle size distribution demonstrate a higher grain growth rate. It is believed that the presence of appropriate amounts of Nd oxides effectively impedes the grain growth process and a larger difference in sizes between pre-alloy powder particles significantly accelerates the grain growth process. On the basis of experimental results, the grain growth exponent and the corresponding activation energy were obtained. A possible grain growth mechanism in NdFeB magnets during sintering was briefly discussed.

关键词： rare earths NdFeB-type magnet sintering grain growth kinetics

Effect of continuous cooling conditions on Microstructure and Mechanical Properties of High Carbon Steel Rod

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International Journal of Minerals,Metallurgy and materials 1999年第4期13卷 277-280页

作者： QingWu Cai1 Yumei Pu2 Di Tang1 Zhenli Mi1 Yuzhou Zhu2(l material Science and Engineering School, University of Science and technology beijing, beijing 100083, China2 Maanshan iron and Steel co. Ltd., Maanshan 243000, China) Univ Sci & technol beijing Sch Mat Sci & Engn Beijing 100083 Peoples R China Maanshan Iron & Steel co Ltd Maanshan 243000 Peoples R China

The effect of cooling rate and austenitizing condition on the mechanical properties of high carbon steel (SWRH82B) has beeninvestigated. Specimens were made of high carbon steel rod and heat-treated by Gleeble-2000 to produce a wide variation in prior austenite size. Different cooling rates were carried out, and then pearlite interlaminar spacing and mechanical properties were measured andtested respectively. According to the results, it could be found that under the continuous cooling with the increase of cooling rate, tensilestrength greatly increases and reduction in area exhibits a slightly increase for an equivalent value of prior austenite grain size. Whenprior austenite size increases, reduction in area decreases, and tensile strength increases slightly for an equivalent value of pearlite interlaminar spacing. It is concluded that prior austenite size primarily controls ductility and pearlite interlaminar spacing controls tensilestrength. mathematical formulae are given for these relations.

关键词： high carbon steel continuous cooling, interlaminar spacing ofpearlite, austenite grain size.

Preparation of Barite/TiO_2 composite Particle and Interaction Mechanism between TiO_2 and Barite Particles

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稀有金属材料与工程 2011年第S3期40卷 193-197页

作者： Wang Baikun, Ding Hao, Wang Yongkui, Liang Ning China University of Geosciences (beijing), beijing 100083, China China Univ Geosci beijing Sch Mat Sci & Technol Beijing 100083 Peoples R China

Barite/TiO2 composite particle (B/TCP) was prepared by coating TiO2 on the surfaces of barite particles through mechano-chemical method. The preparation parameters and pigment properties of B/TCP as well as the interaction mechanism between barite and TiO2 were studied. The results indicated that the mechanical co-grinding process and the proportion of TiO2 affected the properties of B/TCP significantly. B/TCP prepared under optimal conditions was similar to TiO2 in pigment properties. It was mainly the strong electrostatic attraction between barite and TiO2 in water that combined them firmly and then formed B/TCP.

关键词： barite/TiO2 composite particle mechano-chemical titanium dioxide interaction mechanism between particles

Analysis and control on Fracture of 20Mn2A High Tensile Steel for Round Link Chain

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Journal of Iron and Steel Research International 2011年第S1期18卷 898-902页

作者： CAO Shu-wei 1,2,KANG Yong-lin 1,3,ZHAO Xian-ping 2,YANG Chang-chun 1 (1.School of materials Science and Engineering,University of Science and technology beijing,beijing 100083,China 2.technology Center of Anyang Iron & Steel Group co.,Ltd.,Anyang 455004,Henan,China 3.State Key Laboratory for Advanced Metals and materials,University of Science and technology beijing,beijing 100083,China) Univ Sci & technol beijing Sch Mat Sci & Engn Beijing 100083 Peoples R China Anyang Iron & Steel Grp co Ltd Ctr Technol Anyang 455004 Henan Peoples R China Univ Sci & technol beijing State Key Lab Adv Met & Mat Beijing 100083 Peoples R China

Based on the phenomenon of brittle fracture occurred during tensile test for 20Mn2A high strength circular chain used in coal mines,the fracture property is regarded as intercrystalline brittle one after macroscope observation and metallographic *** is analysed that the intercrystalline brittle fracture is due to high tempering temperature and limited processing site where final products are piled together after heat treatment,which lead to a lower cooling rate of internal chain,with Si,Mn and P etc elements segregating and enriching in the austenite grain boundary and forming high tempering *** these circular chains are tempered again for one hour at 670℃,and oil-cooled rapidly,due to the reversibility of high temper brittleness for structural alloy steel,the high temper brittleness can be eliminated and products are completely qualified after tensile inspection.

关键词： high strength circular chain metallographic examination brittle fracture high tempering brittleness improvement measures

The Microstructure Mechanical Property Characteristic of 1Cr17/9Cr18MoV Multilayered Plates

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Journal of Iron and Steel Research International 2011年第S1期18卷 933-935页

作者： XIE Guo-liang 1,WANG Yan-lin 2,LIU Jing 1,HAN Jing-tao 1,GAO Gang 1 (1.School of materials Science and Engineering,University of Science and technology beijing,beijing 100083,China 2.Fangda Special Steel technology co.,Ltd,Nanchang 330012,China) Univ Sci & technol beijing Sch Mat Sci & Engn Beijing 100083 Peoples R China Fangda Special Steel technol co Ltd Nanchang 330012 Peoples R China

A multilayered plate,containing two different steel,1Cr17 and 9Cr18MoV are *** microstructures of both materials and the transition zone of interfaces are investigated by SEM and *** point bending tests are employed to determine its mechanical *** multilayered composite shows a different mechanical property:a much lager bending defection than that of 9Cr18MoV material and a much higher strength than that of 1Cr17 material.

关键词： multilayered plate 1Cr17/9Cr18MoV microstructures mechanical property

Facile and green route to highly luminescent ZnS-shelled CdSe nanocrystals

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Rare Metals 2009年第2期28卷 107-111页

作者： Ye Xinyua Zhuang Weidong Hu Yunsheng Luo Xinyu Zhao Chunlei Huang Xiaowei Gen Res Inst NonFerrous Met Natl Engn Res Ctr Rare Earth Mat Beijing 100088 Peoples R China Grirem Adv mat co Ltd Beijing 100088 Peoples R China Jiangxi Univ Sci & technol Sch Mat & Chem Engn Ganzhou 341000 Peoples R China

Highly luminescent CdSe/ZnS nanocrystals were obtained by adapting non-TOP-based synthesis and a subsequent two-phase ZnS shelling procedure:the core CdSe nanocrystals were synthesized in sole solvent paraffin liquid with cadmium oxide,elemental sele-nium,and oleic acid; the deposition of the ZnS shell was conducted by using zinc stearate in toluene and sodium sulfide in deionized water. The green and low-cost route was proved to be more efficient to constrain the size of core nanocrystals while tuning the ...

关键词： crystal structure characterization solvent growth from solution nanomaterials CdSe/ZnS

Microstructure and Mechanical Properties of Nb-Microalloyed X100 High Deformability Pipeline Steel

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Journal of Iron and Steel Research International 2011年第S1期18卷 707-711页

作者： MENG De-liang 1,KANG Yong-lin 1,AN Shou-yong 2,XIA Dian-xiu 2,SUN Hao 2,ZHENG Xiao-fei 1 (1.School of materials Science and Engineering,University of Science and technology beijing,beijing 100083,China 2.technology Center of Jinan Iron and Steel co.,Ltd.,Jinan 250101,Shangdong,China) Univ Sci & technol beijing Sch Mat Sci & Engn Beijing 100083 Peoples R China Jinan Iron & Steel co Ltd Ctr Technol Jinan 250101 Shangdong Peoples R China

A low carbon Nb-microalloyed high deformability pipeline steel with X100 grade has been processed by TMCP and followed two-stage cooling *** microstructure is characterized by ferrite/bainite *** effective grain size is 1.85μm in *** volume of ferrite is about 10-15% and the grains sizes are mostly less than 5μ*** bainite consists of granular-bainite and lath-bainite,with M/A islands finely *** longitudinal tensile yield strength,uniform elongation,yield ratio are 647MPa,7.6% and 0.78,***/bainite multiphase have large strain hardenability that resulting high strength and high deformability *** of Nb also improves the strength and uniform deformability by precipitation strengthening and grain refinement.

关键词： pipeline steel high deformability high strength microalloyed steel strain based design

Improvement in the Oxidation Resistance of Tungsten by Sol-Gel Derived Al_2O_3 coating

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稀有金属材料与工程 2012年第S1期41卷 303-305页

作者： Fan Ailing1,Meng Lingsheng1,Huang Lang1,2,Ma Jie1 1 college of materials Science and Engineering,beijing University of technology,beijing 100124,China 2 Department of Safety and Environment,Xinyu Iron&Steel Group co.Ltd,Xinyu 338001,China beijing Univ technol Coll Mat Sci & Engn Beijing 100124 Peoples R China Xinyu Iron & Steel Grp co Ltd Dept Safety & Environm Xinyu 338001 Peoples R China

An Al2O3 coating was prepared from aluminum isopropoxide as precursor on tungsten *** dependences of crystalline and phase in Al2O3 coating on temperature were *** results show the coatings being compact,uniform and crack-free can be obtained by suitable *** main phase of coating is α-*** to the uncoated specimens,the ones with coatings synthesized by sol-gel process provide excellent oxidation resistance at high temperature.

关键词： sol-gel process tungsten filament Al2O3 coating