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Chinese Science Bulletin 2001年第22期46卷 1873-1877页

作者： Zhang, J Sun, LD Qian, C Liao, CS Yan, CH Peking Univ PKU HKU Joint Lab Rare Earth Mat & Bioinorgan Chem State Key Lab Rare Earth Mat Chem & Applicat Beijing 100871 Peoples R China

Quaternary water-in-oil reverse micelles consisting of cetyltrimethylammonium bromide (CTAB), n-hexanol, n-heptane and water were prepared and characterized. The optimized reaction conditions were determined, and monodispersed droplets of the reverse micelles were used as microreactors to synthesize CdS nanoparticles. By using transmission electron microscopy (TEM), UV-Vis spectroscopy and fluores.ence spectroscopy, the influences of the reverse micelle components on the size, size distribution, morphology, stability and optical properties of CdS nanoparticles were investigated. CdS nanoparticles with narrow size distribution were obtained and the size range is 6-8 nm when W=24 (W=[water]/[CTAB]), F=5.27 (P=[n-hexanol]/ [CTAB]), [CTAB]=0.2 mol/L, [Cd2+] and [S2-] are 8.45×10-4 mol/L.

关键词： reverse micelles CdS nanoparticles optical properties.

Critical Transitions of Microviscosity in Concentrated Polystyrene Solutions Revealed by Excimer Format.on of Pyrenyl Probes

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Chinese Chemical Letters 1997年第6期8卷 543-546页

作者： Gao, H Wang, GC He, BL NANKAI UNIV STATE KEY LAB FUNCT POLYMER MAT ADSORPT & SEPARATINST POLYMER CHEMTIANJIN 300071PEOPLES R CHINA

Excimer format.on of pyrene and benzyl 4-(1-pyrenyl) butanoate was used to study the microviscosity of polystyrene/toluene solutions over the entire concentration range. Two critical concentrations (C(PS)similar to 0.32, 0.82g/ml) have been observed from the log-log plot of IB/IM vs C-PS. The res.lts are explained in terms of the onset of cohesional interaction and the glass transition of the polymer chains, res.ectively.

关键词： SCATTERING POLYMER

Effect of Na_2CO_3 on Energy Consumption of Micro-arc Oxidation of Magnesium Alloy

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稀有金属材料与工程 2012年第S1期41卷 187-189页

作者： Wang Xiaobo,Tian Xiubo,Gong Chunzhi,Yang Shiqin state key lab.ratory of Advanced Welding and Joining,Harbin Institute of Technology,Harbin 150001,China Harbin Inst Technol Sch Mat Sci & Engn State Key Lab Adv Welding & Joining Harbin 150001 Peoples R China

Micro-arc oxidation(MAO)coatings were fabricated on AZ31 magnesium alloy and the effect of Na2CO3 on the energy consumption was *** res.lts show that the concentration of Na2CO3 has a critical effect on the discharge behavior of MAO *** increasing the Na2CO3 concentration in the electrolyte,the arcing voltage and working voltage decrease.A proper concentration is needed to achieve the highest growth rate of the coatings and the lowest energy consumption per unit coating *** addition of Na2CO3 decreases the arcing and working voltage of MAO *** is attributed to that the Na2CO3 leads to much more micropores.due to the decomposition of MgCO3 to produce more gas.

关键词： magnesium alloy micro-arc oxidation Na2CO3 energy consumption

High Temperature Oxidation and Wear res.stance of Y-modified Hot Dipping Aluminized Coating on SCH12 Steel

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稀有金属材料与工程 2012年第S1期41卷 231-235页

作者： Fan, X. S. Yang, Z. G. Zhang, C. Tsinghua Univ Dept Mat Sci & Engn State Key Lab New Ceram & Fine Proc Beijing 100084 Peoples R China

Microstructures.high-temperature oxidation and wear res.stance of hot dipping Al-Si-Y coating on SCH12 heat res.stant cast steel were investigated in this *** aluminized coating was characterized by scanning electron microscopy(SEM),energy dispersive X-ray spectrometry(EDX)and X-ray diffraction(XRD).The res.lts showed that the coating was composed of the Al-rich outer layer and the intermetallics inner *** the Al-rich layer,some Y-rich precipitates and Fe-Al-Si-Cr precipitates could be *** intermetallics layer pres.nted three layers induced by the increase of Fe,Cr,Ni content and the corres.onding decrease of Al,Si *** oxidation tests were conducted in still air at 850℃for up to 100 *** oxidation,a top oxide scale composed of mainlyα-Al2O3,Al5Y3O12 was formed on the steel *** intermetallics beneath the oxide scale consisted of mainly FeAl and small amount of Fe2Al5 and Cr3Si *** mass gain of the coated and uncoated SCH1steel is 0.45 mg/cm 2 and 0.57 mg/cm 2,*** wear res.stance was investigated using a high-temperature pin-on-disc tribometer at 650℃.The wear rate for the coated and uncoated steel is 0.45μm 3 /μm.N and 3.01μm 3 /μm.N,*** high temperature wear tests and oxidation tests res.lts demonstrated that the yttrium-modified aluminized specimen had significantly improved high-temperature wear res.stance and equivalent oxidation res.stance compared with the original SCH12 specimen.

关键词： hot dipping aluminizing oxidation res.stance high-temperature wear res.stance

Microstructure and Temperature Distribution in ZnAl_2O_4 Sintered Body by Pulse Electric Current

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Journal of mat.rials Science & Technology 2003年第6期19卷 526-528页

作者： Dongming ZHANG, Zhengyi FU and Jingkun GUOstate key lab. of Advanced Technology for mat.rials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China Wuhan Univ Technol State Key Lab Adv Technol Mat Synth & Proc Wuhan 430070 Peoples R China

Microstructure of reaction sintering of ZnAl2O4 at 1500℃ by hot-pres.ing(HP) and pulse electric current was investigated. The res.lts indicated that the existed cracks in sintered body were caused by structure mismat.h. It is the evidence that periodical temperature field existed during pulse electric current sintering of nonconductive mat.rials. The distance between high temperature areas was related to die diameter.

关键词： Pulse electric current sintering Reaction sintering ZnAl2O4,Microstructure Temperature distribution.

Effect of Preparation Technology Parameters on the res.riction Performances of Unitary Titanium Porous res.rictor

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稀有金属材料与工程 2011年第S3期40卷 301-305页

作者： Tan Ping1, Pang Guangqing2, Tang Huiping1, Chen Jinmei1, Ge Yuan1, Wang Qiangbin1, Kang Xinting1 1state key lab.ratory of Porous Metal mat.rials, Northwest Institute for Nonferrous Metal res.arch, Xi’an 710016, China 2Xi’an Baoder Powder Metallurgy CO.LTD, Xi’an 710016, China NW Inst Nonferrous Met res State Key Lab Porous Met Mat Xian 710016 Peoples R China Xian Baoder Powder Met CO LTD Xian 710016 Peoples R China

Unitary titanium porous res.rictor was prepared by a sintering welding technique. The res.lts indicated that the res.riction performance of unitary Ti porous res.rictor was not only dependent on the morphology and particle size of the original powder, but also influenced by the molding pres.ure, sintering temperature and sintering pres.ure. The res.rictor obtained from titanium powder with large particle size or spherical morphology possesses big porosity, large pore size and high permeability but low res.riction. Instead, the res.rictor derived from fine powder with irregular morphology had small porosity, narrow pore size but high res.riction performance. In addition, the res.riction ability of the titanium porous res.rictor metals increased by increasing of molding and sintering pres.ure and the sintering temperature. However, a much higher sintering temperature induced a bad welding status, which ascribed to excessive sintering shrinkage of the porous res.rictor, and the cracks between the porous body and the compact shell easily occurred. Finally, the strength of the dense Ti shell would decrease due to the flaws caused by the grain growth during sintering process. It was an ideal method to avoid the grain growth at high temperature through increasing the molding and sintering pres.ure and decreasing the sintering temperature, which could obtain a good sinter behavior and air tightness between the porous body and the Ti shell, thus, which satisfied the requirements in the applications.

关键词： unitary titanium porous metal res.rictor sinter diffusion welding

Interfacial structure and mechanical property of Mg/Al alloy joint diffusion bonded with Zn interlayer metal

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Rare Metals 2007年第S1期26卷 296-300页

作者： ZHAO Limin,ZHANG Zhaodong,and HAO Shengzhi state key lab.ratory of mat.rials Modification by Laser,Ion and Electron Beams,Dalian University of Technology,Dalian 116024,China Dalian Univ Technol State Key Lab Mat Modificat Laser Ion & Electron Dalian 116024 Peoples R China

The characteristics of microstructure and mechanical strength of the Mg/Al alloy joint diffusion bonded with a Zn interlayer were studied by means of metalloscopy,X-ray diffraction(XRD),electron probe microanalysis(EPMA) and mechanical property *** showed that the Mg/Al alloy joint diffusion bonded with Zn interlayer consists of a multilayer sandwich structure,including the transition zone on Al side,Zn and Zn-Mg transition zone,as well as the transition zone on Mg *** transition zone on Al side is very thin and composed mainly of a solid solution structure,while the Zn-Mg transition zone has a relative larger dimension after a rapid eutectic *** addition of zinc interlayer inhibits the inter-diffusion of Mg and Al alloy *** Zn-Mg transition zone constitutes the main part of the joint and consists of Mg crystals and the new phase formed is MgZn intermetallic *** mechanical strength of Mg/Al alloy joints diffusion bonded with Zn interlayer reached 42 *** to the phase constitution analyses executed on each side of the fracture face,it was deduced that the fracture of Mg/Al alloy joint located around the interface of Zn and Zn-Mg transition zone.

关键词： magnesium alloy aluminum alloy zinc interlayer diffusion bonding joint strength

Microstructure and Tribological Behavior of Cr-Cu-N Coatings Deposited by Ion Beam Assisted Magnetron Sputtering

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稀有金属材料与工程 2012年第S1期41卷 355-358页

作者： Tian Linhai Zhang Yang Yang Yaojun Zhu Xiaodong Tang Bin Taiyuan Univ Technol Res Inst Surface Engn Taiyuan 030024 Peoples R China Xi An Jiao Tong Univ State Key Lab Mech Behav Mat Xian 710049 Peoples R China

Cr-Cu-N coatings with copper content from 0 at%to 6.8 at%were deposited on silicon and M2 steel by ion beam assisted magnetron *** microstructure and composition of the coatings were characterized using SEM,GDOES,XRD and *** mechanical properties of the coatings were tested on a standard hardness *** tribological behavior of the coatings in dry wear condition was studied by means of ball-on-disc wear *** experimental res.lts show that addition of copper can res.rict the columnar crystal growing to a certain *** and XPS analysis indicate that coatings are mainly composed of Cr and CrN *** is mainly existed in a free state in the *** adding has no obvious effects on the hardness of the ***,the coatings fracture toughness can be improved by doped *** coefficient of friction of the coatings against bearing steel is in the range of 0.25-0.6 changing with the copper *** coating with 2.6 at%copper shows the lowest coefficient of friction about 0.25 and wear rate which is about one tenth of that of the coating with 6.8 at%*** higher coefficient of friction and wear rate of the coating with 6.8at%copper may be attributed to its lower bonding strength.

关键词： Cr-Cu-N coatings ion beam assisted magnetron sputtering microstructure tribological behavior

res.dual Stres. Measurement in Electron Beam Welded Joints of 50mm Thick Titanium Alloy

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稀有金属材料与工程 2011年第S4期40卷 44-48页

作者： Wu Bing1,2,Zhang Jianxun1,Liu Chuan1,Gong Shuili2 1state key lab.ratory for Mechanical Behavior of mat.rials,Xi’an Jiaotong University,Xi’an 710049,China2Science and Technology on Power Beam Processes lab.ratory,Beijing Aeronautical Manufacturing Technology res.arch Institute,Beijing 100024,China Beijing Aeronaut Mfg Technol res.Inst Sci & Technol Power Beam Proc Lab Beijing 100024 Peoples R China Xi An Jiao Tong Univ State Key Lab Mech Behav Mat Xian 710049 Peoples R China

For res.arching the res.dual stres. distribution characteristics of the different large thickness titanium alloy joints by electron beam welding,under heat treatment or non-heat treatment conditions,the changes in res.dual stres. distribution characteristics of electron beam welding joints,which thickness is 50 mm,were measured using blind-hole method with local layer-by-layer *** of post-welding heat treatment on the res.dual stres. distribution also *** res.lts show that blind-hole method with local layer-by-layer removal is suitable to measure res.dual stres.es in thick plate,and good to reflect the welded res.dual stres. distribution of large *** stres. of the test samples in the weld and heat affected zone has high stres. level,and internal stres. dramat.c changes with thickness in this *** heat treatment,the samples' stres. distributions were significantly *** samples' transverse and longitudinal res.dual stres. are basically the *** is obvious.

关键词： electron beam welding thick plate res.dual stres. measurement blind-hole method local layer-by-layer removal re-sidual stres. distribution

Influence of TiO_2 Nano Particles on the res.stance to Corrosion and Mechanism of Cr_2O_3

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稀有金属材料与工程 2012年第S1期41卷 319-322页

作者： Cheng Xudong1,Peng Sheng1,Zhou Jiliang2,Zhu Zhenqi1 1 state key lab.ratory of Advanced Technology for mat.rials Synthesis and Processing,Wuhan University of Technology,Wuhan 430070,China 2 key lab.ratory of Catalysis and mat.rials Science of the state Ethnic Affairs Commission&Ministry of Education,Hubei Province,South-central University for Nationalities,Wuhan 430074,China Wuhan Univ Technol State Key Lab Adv Technol Mat Synth & Proc Wuhan 430070 Peoples R China state Ethn Affairs Commiss Key Lab Catalysis & Mat Sci Wuhan 430074 Hubei Province Peoples R China S Cent Univ Nationalities Minist Educ Wuhan 430074 Hubei Province Peoples R China

Cr2O3-based ceramic composite coatings with a NiCr intermediate layer adding nano TiO2 particles were synthesized by Air plasma spraying(APS)followed further seal *** coating samples were characterized by X-ray diffractions(XRD),scanning electron microscope(SEM).The corrosion behavior of coating was measured by weight loss in three solutions(HCl,NaOH,and NaCl).The relationships between the microstructure,corrosion behavior,and the content of TiO2 in coatings were *** the content of TiO2 was relative high,the coating was composed of(Cr0.88Ti0.12)2O3 and Cr2O3 *** sealing,the coating weight decreased all long in three kinds of ***,after sealing treatment the coating weight decreased early but increased later,changed periodically as *** curve and electrochemical impedance spectroscopy(EIS) were performed to study the corrosion *** res.lts showed that like organic coating,the corrosion of ceramic coating included three stages,in which the weight of samples decreased or increased corres.onding to different physical and physical or chemical *** salt spray test showed the Cr2O3-based ceramic composite coating had an excellent decay res.stance in marine environment.

关键词： corrosion res.stance ceramic coating air plasma spray