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EFFECT OF Cu-Ni CONTENT ON THE CORROSION RESISTANCE OF(Cu-Ni)/(10NiO-90NiFe_2O_4)CERMET INERT ANODE FOR AlUMINUM ElECTROlYSIS

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Acta Metallurgica Sinica(English letters) 2008年第1期21卷 72-78页

作者： Z.l. Tian Y.q. lai J. li Y.x. liu School of Metallurgical Science and Engineering Central South University Changsha 410083 China

（Cu-Ni）/（10NiO-90NiFe204） cermet inert anodes containing metal Cu-Ni0, 5, 10, 15 and 20 wt pct were prepared and their corrosion resistance to Na3AlF6-Al2O3 melts was investigated. The results indicate that the content of metal Cu-Ni has little effect on the steady-state concentration of Ni in the electrolyte and the values could not be used to effectively differentiate their corrosion resistance. The steady-state concentration of Fe decreases from 304×10^-6 to 168×10^-6 and that of Cu increases from 21×10^-6 to 71×10^-6 with the content of metal Cu-Ni increasing from 0 to 20 wt pct. Post-examination shows that metallic phase Cu-Ni is corroded preferentially during electrolysis and many pores are left at the anode surface. Considering the corrosion resistance and electrical conductivity, the cermet containing metal Cu-Ni 5 wt pct should be selected and studied further.

关键词： Aluminum electrolysis Inert anode NiFe2O4 based cermet Corrosion resistance

Design and Pilot Programs of Marine Exposure Station of A Sea-crossing Bridge

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武汉理工大学学报 2010年第17期32卷 131-136页

作者： qIN M q WANG C J TU l q ZHANG G Z SUN T x Wuhan Harbour Engineering Design and Research Co. ltd. Wuhan 430071China Key lab of large-span Bridge Construction Technology Ministry of CommunicationsWuhan 430071China Zhejiang Province Zhoushan Island linking Construction Commanding Department Zhoushan 316032China School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China

This paper presents the location,the structural design as well as the anti-corrosion and the pilot programs of the marine exposure station of Zhoushan Archipelago seas sea-crossing bridges. Subjected to the marine environment,the concrete structures in serve with different mixing proportions,cover thickness,additional anti-corrosion measures such as rust-preventing agent,coating,penetration crystalline waterproof material,silicone and permeable fabric were studied. Those results obtained provide important information for the maintenance of marine concrete and the structural design of sea-crossing bridges in the above sea area.

关键词： exposure station sea-crossing bridge marine concrete durability design

Constructing two-scale network microstructure with nano-Ti5Si3 for superhigh creep resistance

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Journal of Materials Science & Technology 2019年第8期35卷 1532-1542页

作者： Y.Jiao l.J.Huang S.l.Wei H.x.Peng q.An S.Jiang l.Geng State Key laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001 China Center of Analysis and Measurement Harbin Institute of TechnologyHarbin 150001 China Department of Materials Science and Engineering Massachusetts Institute of TechnologyCambridge MA02139 USA Institute for Composites Science Innovation (InCSI) School of Materials Science and EngineeringZhejiang UniversityHangzhou 310027 China

The improvement of mechanical properties must be achieved by designing and constructing more suitable microstructure,such as hierarchical *** order to significantly enhance the creep resistance of titanium matrix composites(TMCs),two-scale network microstructure was constructed including the first-scale network(le network(llurgy and in-situ *** results showed that the creep rate of the composite was remarkably reduced by an order of magnitude compared with the Ti6Al4V alloy at 550℃,600℃,650℃ under the stresses between 100 MPa and 350 ***,the rupture time of the composite was increased by 20 times,compared with that of the Ti6Al4 Valloy at 550℃/300 *** superior creep resistance could be attributed to the hierarchical *** micro-TiBw reinforcement in the first-scale network boundary contributed to creep resistance primarily by blocking grain boundary sliding,while the nano-Ti5Si3 particle in the second-scale network boundary mainly by hindering phase boundary *** addition,the nano-Ti5Si3 particle was dissolved,and precipitated with smaller size than the primary *** phenomenon was attributed to Si element diffusion under high temperature and external stress,which could further continuously enhance the creep ***,the creep rate during steady-state stage was significantly decreased,which manifested superior creep resistance of the composite.

关键词： Titanium matrix composite Two-scale network microstructure Nano-Ti5Si3 Creep Powder metallurgy

Finite Element Simulation on Thermal Fatigue of a Turbine Blade with Thermal Barrier Coatings

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Journal of Materials Science & Technology 2014年第4期30卷 371-380页

作者： l.Yang q.x.l.u Y.C.Zhou W.G.Mao C.lu Key laboratory of low Dimensional Materials & Application Technology(Ministry of Education) Xiangtan University Faculty of Materials Optoelectronic & PhysicsXiangtan University Department of Mechanical Engineering Curtin University

In this paper, a finite element model was developed for a turbine blade with thermal barrier coatings to investigate its failure behavior under cyclic thermal loading. Based on temperature and stress fields obtained from finite element simulations, dangerous regions in ceramic coating were determined in terms of the maximum principal stress criterion. The results show that damage preferentially occurs in the chamfer and rabbet of a turbine blade with thermal barrier coatings and its thermal fatigue life decreases with the increase of thermal stress induced by high service temperature.

关键词： Turbine blade Thermal barrier coatings Finite element model Thermal fatigue life prediction

INVESTIGATION OF WO3-DOPED TiO2 FIlM COMPOSITE PHOTOCATAlYST

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Acta Metallurgica Sinica(English letters) 2004年第3期17卷 263-268页

作者： q.F. Meng K.R. liu l. Jiang q. Han J.S. Chen x.J. Wei School of Materials & Metallurgy Northeastern University Shenyang 110004 ChinaSchool of Materials & MetallurgyNortheastern University Shenyang 110004 ChinaSchool of Materials & MetallurgyNortheastern University Shenyang 110004 ChinaSchool of Materials & MetallurgyNortheastern University Shenyang 110004 ChinaSchool of Materials & MetallurgyNortheastern University Shenyang 110004 ChinaSchool of Materials & MetallurgyNortheastern University Shenyang 110004 China

The nano--crystal composite WO_3-TiO_2 photocatalyst was prepared by ultrasonic as-sisted sol--gel process. The effects of various factors, such as the crystal form, thesubstrates, the pH, the dissolved oxygen and the ultrasonic on the photocatalytic ac-tivity were investigated in view of the photodegradation of Rhodamine B. The resultsshow that the crystal form of WO_3-TiO_2 film with highest photocatalytic activity isrutile. The introduction of ultrasonic to the course of preparation can accelerate thedeposit time of the sol and increase the photocatalytic activity significantly in view ofthe highest photodegradation of Rhodamine B being 72.7% in 5 hours. The poroustitanium plate is the most suitable substrate in four kinds of investigated materials.Meanwhile the smaller the pH and the higher the concentration of the dissolved oxygenin the solution is, the higher the photodegradation is.

关键词： ultrasonic sol-gel process photocatalytic photodegradation

FEM SIMUlATION FOR lASER FORMING PROCESSING

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Acta Metallurgica Sinica(English letters) 2004年第3期17卷 317-322页

作者： l.q.li Y.B.Chen x.Y Wang S.Y lin State Key laboratory of Advanced Welding Production Technology Harbin Institute of Technology Harbin 150001 China Harbin Research Institute of Welding Harbin 150001 ChinaState Key Laboratory of Advanced Welding Production Technology Harbin Institute of Technology Harbin 150001 China Harbin Research Institute of Welding Harbin 150001 ChinaHarbin Research Institute of Welding Harbin 150001 ChinaHarbin Research Institute of Welding Harbin 150001 China

laser forming involves heating sheet metal workpiece along a certain path with adefocused laser beam directed irradiate to the surface. During laser forming, a tran-sient temperature fields is caused by the irradiation and travelling of a laser beam.Consequently, thermal expansion and contraction take place, and allows the thermal-mechanical forming of complex shapes. This is a new manufacturing technique thatforming metal sheet only by thermal stress. Therefore, the analysis of temperaturefields and stress fields are very useful for studying the forming mechanism and con-trolling the accuracy of laser forming. The non--liner finite element solver, MARC, isemployed to solve the thermal--mechanical analysis. Using this model, the stress andstrain distribution of pure aluminum plate with different thickness are analyzed. Theinfluence of scanning speed on temperature fields and plastic strain of metal sheet un-der the condition of constant line energy are also presented. Numerical results agreewell with the experimental results.

关键词： laser forming FEM simulation temperature fields stress distributton

Stochastic averaging of quasi integrable and resonant Hamiltonian systems excited by fractional Gaussian noise with Hurst index 1/2

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Acta Mechanica Solida Sinica 2017年第1期30卷 11-19页

作者： q.F.lü M.l.Deng W.q.Zhu Department of Mechanics State Key Laboratory of Fluid Power and Mechatronic SystemsKey Laboratory of Soft Machines and Smart Devices of Zhejiang ProvinceZhejiang University

A stochastic averaging method of quasi integrable and resonant Hamiltonian systems under excitation of fractional Gaussian noise （fGn） with the Hurst index 1/2 〈 H 〈 1 is proposed. First, the definition and the basic property of fGn and related fractional Brownian motion （iBm） are briefly introduced. Then, the averaged fractional stochastic differential equations （SDEs） for the first integrals and combinations of angle variables of the associated Hamiltonian systems are derived. The stationary probability density and statistics of the original systems are then obtained approximately by simulating the averaged SDEs numerically. An example is worked out to illustrate the proposed stochastic averaging method. It is shown that the results obtained by using the proposed stochastic averaging method and those from digital simulation of original system agree well.

关键词： quasi integrable and resonant Hamiltonian system Fractional Brownian motion Fractional Gaussian noise Stochastic averaging method Internal resonant

NANOSIZE EFFECT IN GRAIN BOUNDARY MIGRATION OF COPPER

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Acta Metallurgica Sinica(English letters) 2004年第1期17卷 11-15页

作者： l.Zhou x.q.Wei N.G.Zhou D.G.li School of Materials Science and Engineering Nanchang UniversityNanchang 330047ChinaSchool of Materials Science and EngineeringNanchang UniversityNanchang 330047ChinaSchool of Materials Science and EngineeringNanchang UniversityNanchang 330047ChinaCentral Iron and Steel Research InstituteBeijing 100083China

Molecular dynamics simulations of high temperature annealing of copper bicrystals have been carried out. The bicrystals have planar grain boundaries, and the gain size varies in nano range. An EAM (embedded atom method) potential of FS type is used for calculating the interatomic forces. The results show that in nanocrystalline copper, GB migration driven by inter-GB reaction can take place. A critical grain size is identified, below which the inter-GB reaction becomes strong enough to trigger GB motion, which accelerates rapidly and leads to annihilation of the grain boundaries. The critical size is found to be 16 atomic radii. A "through intermediate grain mechanism" is identified for the nano-grain boundary motion observed, which is never reported for GB migrations of conventional polycrystalline metals.

关键词： grain boundary migration nanocrystal copper

Synergistic O^(2-)/li^(+) Dual Ion Transportation at Atomic Scale

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Research 2019年第1期2019卷 1260-1267页

作者： F.q.Meng q.H.Zhang A.Gao x.Z.liu J.N.Zhang S.Y.Peng x.lu l.Gu H.li Beijing National laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China School of Materials Sun Yat-Sen UniversityGuangzhou 510275China College of Materials Science and Engineering Jiangxi University of Science and TechnologyJiangxi 341000China Songshan lake Materials laboratory DongguanGuangdong 523808China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China

Te ion migration during electrochemical process is a fundamental scientifc issue for phase transition behavior and of technical importance for various functional devices,where cations or anions are active under electrical *** only one type of functional ion,O^(2-)or li^(+),is activated due to their diferent migration energy barriers,cooperated by the valence change of other immobile ions in the host lattice matrix,e.g.,Co^(2+)/Co^(3+)and Mn^(3+)/Mn4+redox couples,owing to the charge *** we select spinel li4Ti5O12 as anode and construct an all-solid-state battery under a transmission electron microscope;a synergistic transportation of O^(2-)and li^(+)driven by an electrical bias was directly observed at the atomic scale.A small amount of oxygen anions was extracted frstly as a result of its lowest vacancy formation energy under 2.2 V,leading to the vertical displacement of *** to 2.7 V,an ordered phase with both li-and O-defciency *** li^(+)and O^(2-)ions are simultaneously extracted out from the[liO_(4)]tetrahedra due to the electroneutrality *** migration paths of O and li have been proposed and verifed by frst-principles *** results reveal a brand new synergistic ion migration manner and may provide up-to-date insights on the transportation process of lithium ion conductors.

关键词： synergistic battery migration