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Element distribution and difusion behavior in Q&P steel during partitioning

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International Journal of Minerals,Metallurgy and Materials 2013年第11期20卷 1050-1059页

作者： Hai-tao Jiang Bao-tong zhuang xiao-ge Duan Yan-xin Wu Zheng-xu Cai National Engineering Research Center for Advanced Rolling Technology University of Science and Technology Beijing

Carbon, manganese, and silicon distribution in quenching and partitioning （Q＆P） steel during partitioning process was investigated to reveal the diffusion behavior. The microstructure and chemical composition were analyzed by means of scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, and three-dimensional atom probe. It is shown that the studied Q＆P steel consisted of martensite laths and thin, film-like retained austenite showing extraordinary phase transformation stability. Carbon atoms mostly diffused to the retained austenite from martensite at a higher partitioning temperature. In the experimental steel partitioned at 400℃ for 10-60 s, carbides or cementite formed through carbon segregation along martensite boundaries or within the martensite matrix. As a result of carbon atom diffusion from martensite to austenite, the carbon content in martensite could be ignored. When the partitioning process completed, the constrained carbon equilibrium （CCE） could be simplified. Results calculated by the simplified CCE model were similar to those of CCE, and the difference between the two optimum quenching temperatures, where the maximum volume fraction of the retained austenite can be obtained by the Q＆P process, was little.

关键词： steel heat treatment quenching partitioning element distribution diffusion microstructure

Transient liquid-phase bonding of superalloy K465 using a Ni-Cr-Fe-B-Si amorphous interlayer alloy

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Rare Metals 2020年第4期39卷 408-412页

作者： Ji-De Liu Bo Li Yuan Sun Tao Jin xiao-Feng Sun zhuang-Qi Hu Department of Superalloys Institute of Metal ResearchChinese Academy of ScienceShenyang 110016China

A kind of Ni-Cr-Fe-B-Si system amorphous alloy was used as interlayer in transient liquid-phase bonding(TLP bonding)of polycrystalline superalloy *** bonding behavior,microstructure feature and the tensile properties of the joints were *** are B-rich phase and Si-rich phase formed in the center of the seam after bonding at 1210℃for 30 *** isothermal solidification is complete after bonding at 1210℃for 4 *** relationship of the average width of the remnant eutectic zone and bonding time at 1210℃is *** tensile strength of the bonded joint at room temperature and 900℃is comparable to that of K465 alloy.

关键词： Interlayer alloy Transient liquid-phase bonding Superalloy K465 Alloy

Portevin–Le Chatelier Effect in Nimonic 263 Superalloy

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Acta Metallurgica Sinica(English Letters) 2015年第5期28卷 542-549页

作者： Guo-Ming Han Cheng-Gang Tian Chuan-Yong Cui zhuang-Qi Hu xiao-Feng Sun Institute of Metal Research Chinese Academy of Sciences

The Portevin-Le Chatelier （PLC） effect in the Nimonic 263 superalloy was investigated by tensile test at a wide temperature ranges from 293 to 1033 K and strain rates between 0.1 and 6.25 × 10^-6 s-1. Simple binary alloys Ni- 0.4C, Ni-24Cr and Ni-5（8）Mo were also tested in order to identify which elements were responsible for the PLC effect in the Nimonic 263 alloy. The results demonstrated that for Nimonic 263 alloy, PLC effect occurred at certain temperatures and low strain rates. Normal PLC effect exhibiting type-A and -（A ＋ B） serrations was attributed to the enhanced solute diffusion with increasing temperature, while inverse PLC effect with type-C serration was caused by unlocking process. The activation energy for the normal PLC effect was calculated to be 68 kJ/mol, and diffusion of substitutional solutes such as Cr and Mo was identified to be responsible for the PLC effect. In comparison with the PLC effect in simple binary alloys, solute atmospheres formed by different kinds of atoms in Nimonic 263 alloy work more effectively, increasing locking strength and corresponding mean stress drop magnitude.

关键词： PLC effect Dynamic strain aging Nickel-base alloys Solute atom

Offsetting the thermal expansion mismatch:a new way to high-performance solid oxide fuel cell cathodes

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Science China Chemistry 2021年第6期64卷 877-878页

作者： Lin zhuang College of Chemistry and Molecular Sciences Hubei Key Lab of Electrochemical Power SourcesWuhan UniversityWuhan 430072China The Institute for Advanced Studies Wuhan UniversityWuhan 430072China

On the cutting-edge of developing high-performance solid oxide fuel cells(SOFC),high activity and durability cathodes are required[1,2].However,the thermo-mechanical mismatch between SOFC cathode and electrolyte is the most hindering disadvantage of traditional highly active cathode materials(cobalt-containing perovskites)which usually yield higher thermal-expansion coefficient(TEC)than electrolytes[3].

关键词： expansion mismatch performance

Bonding Interface Imaging and Shear Strength Prediction by Ultrasound1

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Chinese Physics Letters 2010年第6期27卷 118-121页

作者： LI Yong-An MAO Jie LI Ming-Xuan WANG xiao-Min AN Zhi-Wu zhuang Qiao State Key Laboratory of Acoustics Institute of Acoustics Chinese Academy of Sciences Beijing 100190

The propagation of a longitudinal ultrasonic wave normally incident upon an adhesively bonded structure is stud- ied. The structure consists of adherend and adhesive layers with finite thickness. Interfaces between adherend and adhesive are regarded as distributed springs. Theoretical and experimental results show that resonant frequencies of the bonded structure vary sensitively with the interface stiffness constants and adhesive thickness, and these interface characteristics are inversed by the simulation annealing （SA） method. Furthermore, the distribution image of interface stiffnesses is compared with the state of fracture interface, and quantitative prediction of shear strength is achieved based on the distribution of interface stiffnesses and adhesive thicknesses by using a back- propagation neutral network. The average relative error of the shear strength from prediction to real value is 10.7%.

关键词： Ultrasonics Fractures Waves Adhesives Ultrasound imaging Numerical simulations

Synthesis of boron nitride nanotube films with a nanoparticle catalyst

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Chinese Chemical Letters 2016年第6期27卷 871-874页

作者： Cui-Cui zhuang Jia Feng Hong Xu Ling Li xiao-Wei Liu MEMS Center Harbin Institute of Technology

Boron nitride nanotube（BNNT） films were synthesized by combining ball milling and thermal chemical vapor deposition（CVD） using nano-Fe3O4 as a catalyst. The as-produced BNNTs have a bamboo-like structure and have a diameter in the range of 50~200 nm with an average length of more than 40 ***, BNNT nanojunction structures were synthesized. The structure and morphology of the BNNTs were characterized by XRD, SEM, TEM and HRTEM. The possible growth mechanism of BNNTs and BNNT nanojunction structures were proposed. Though the BNNT films were observed, out of our expectation,BNNTs with thin tube wall and small average diameter have not been achieved, and this could be mainly ascribed to the aggregation of the nanoparticle catalyst, resulting in greater catalyst particles during the process of BNNT growth. This result will provide a promising approach to obtain the desired shape of BNNTs and produce branched junctions of BNNTs.

关键词： BNNT films Nano-Fe3O4 Nanoparticle catalyst Ball milling Microstructure

Effect of Screw-Dislocation on Electrical Properties of Spiral-Type Bi2Se3 Nanoplates

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Chinese Journal of Chemical Physics 2016年第6期29卷 687-692,I0001页

作者： Yu-kun Wu A-wei zhuang Chun-miao Ye Jie Zeng Nan Pan xiao-ping Wang HefeiNationalLaboratoryforPhysicalSciencesattheMicroscaleandDepartmentofPhysics UniversityofScienceandTechnologyofChinaHefei230025China

We systematically investigated the electrical nanoplates through field effect transistor and properties of spiral-type and smooth Bi2Se3 conductive atomic force microscopy （CAFM） measurement. It is observed that both nanoplates possess high conductivity and show metallic-like behavior. Compared to the smooth nanoplate, the spiral-type one exhibits the higher carrier concentration and lower mobility. CAFM characterization reveals that the conductance at the screw-dislocation edge is even higher than that on the terrace, implying that the dislocation can supply excess carriers to compensate the low mobility and achieve high conductivity. The unique structure and electrical properties make the spiral-type Bi2 Se3 nanoplates a good candidate for catalysts and gas sensors.

关键词： Bi2Se3 nanoplates Screw-dislocation Electrical properties Field effect tran-sistor Conductive atomic force microscopy

Highly two-photon and X-ray excited long-persistent luminescence in a crystalline host-guest aggregate

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Aggregate

Aggregate 2024年第2期5卷 328-335页

作者： Qiang-Sheng Zhang xiao-Dong Zhang Jia-Yi zhuang Mei Pan MOE Laboratory of Bioinorganic and Synthetic Chemistry Lehn Institute of Functional MaterialsIGCMEGBRCE for Functional Molecular EngineeringSchool of ChemistrySun Yat-Sen UniversityGuangzhouP.R.China Hainan Provincial Key Laboratory of Fine Chem School of Chemistry and Chemical EngineeringHainan UniversityHaikouP.R.China

As a unique type of supramolecular self-assemblies,crystalline host-guest aggregates have attracted extensive interests in multiple application ***,a crystalline host-guest aggregate LIFM-HG1 was obtained with curcubit[8]uril as the host and carboxypyridinium salt as the ***-crystal structural analysis indicates that the presence of abundant weak interactions in LIFM-HG1 provides a rigid environment for the guest molecule and effectively blocks the external *** analysis and theoretical calculations confirm the presence of robust triplet energy levels in *** more impressively,the intersystem crossing channels of the guest molecules are greatly opened up after the formation of the crystalline host-guest aggregate,resulting in a large k_(isc)of 6.70×10^(7)s^(−1)at room temperature for LIFM-HG1(which is∼0 for pure guest),leading to fascinatingmultichannel(including one-photon,two-photon,and X-ray)excited LPL *** addition,the crystalline LIFM-HG1 has a much higher triplet state luminescence efficiency under X-ray and two-photon excitation than that under single-photon excitation(A_(P)/A_(F)=86.8,44.8,10.7 under the three circumstances,respectively).And the phosphorescent emission intensity of LIFM-HG1 is 27.6 times higher than that of the crystalline guest under X-ray *** a result,LIFM-HG1 shows a long afterglow retention time under both single-and two-photon excitation,and an impressive afterglow retention time of 1 s under X-ray ***,the excellent lysosomal targeting and low cytotoxicity by the formation of host-guest aggregate makes LIFM-HG1 promising to be used as a novel lysosomal-targeted two-photon excited phosphorescent tracer.

关键词： crystalline host-guest aggregate long-persistent luminescence two-photon X-ray excited

Studies on GIS Based Tracing and Traceability of Safe Crop Product in China

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Agricultural Sciences in China 2007年第6期6卷 724-731页

作者： QU xiao-hui zhuang Da-fang QIU Dong-sheng Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 P.R.China

The safety of safe crop products （SCP） is critical to maintain people＇s health and living standard. With the global efforts on the improvement of the traceability of food products, it is inevitable to establish corresponding traceability systems to monitor the safety of crop products in China. In this article, the supply chain pattern of SCP in China has been analyzed and its spatial characters have been described in detail. The study deals with on how to relate traceability technology with GIS, and on how to trace and retrace the safety of SCP using the function of excellent spatial representation, spatial locating, and spatial analysis provided in GIS, which has been discussed from several aspects, such as coding technique of traceability information, transferring technique of traceability information, spatialization of traceability information, and application integration of traceability system. A pilot study was carried out to present the basic functions of the system, which provided an efficient and credible way to trace and retrace the safety of SCP in a real supply chain. An innovative idea has been brought forward for how to establish an efficient, credible, applied traceability system of SCP.

关键词： safe crop products (SCP) tracing and traceability GIS traceability code information transformation