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Acta Metallurgica sinica(English Letters) 2021年第2期34卷 265-277页

作者： L.B.Tong j.h.Chu D.N.Zou q.sun s.Kamado h.G.Brokmeier M.Y.Zheng school of Metallurgical Engineering Xi'an University of Architecture and TechnologyXi'an 710055China school of Materials science and Engineering.harbin Institute of Technology Harbin 150001China College of Materials science and Engineering.jilin University Changchun 130025China Department of Mechanical Engineering Nagaoka University of TechnologyNagaoka 940-2188Japan Institute of Materials science and Engineering Clausthal University of TechnologyAgricolastrasse 638678 Clausthal-Zellerfeld.Germany

In this study,the mechanical properties and damping capacities of cast Mg-5.5 Zn-0.6 Zr(weight percent,ZK60)alloys have been simultaneously improved by a facile multi-directional forging(MDF)processing,and the mechanisms of microstructure evolution and texture modification are systematically *** activation of tension twinning occurs during the initial MDF stage,due to the coarse-grained structure of the as-cast *** increasing MDF passes,the continuous dynamic recrystallization(CDRX)results in a fine equiaxed-grain *** typical non-basal texture is formed in the as-MDFed alloy for 6 passes,with the(0001)planes inclined 60°–70°to forged direction and 10°–20°to transverse direction,respectively.A good balance between the strength(~194.9 MPa)and ductility(~24.9%)has been achieved,which can be ascribed to the grain refinement,non-basal texture and fine precipitate *** damping capacity is remarkably improved after MDF processing,because the severe deformation increases the dislocation density,which effectively enlarges the sweep areas of mobile dislocations.

关键词： Mg alloy Multi-directional forging Microstructure Texture evolution Mechanical properties Damping capacity

Many-objective optimization for coordinated operation of integrated electricity and gas network

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journal of Modern Power systems and Clean Energy 2017年第3期5卷 350-363页

作者： Y.N.KOU j.h.ZhENG Zhigang LI q.h.WU school of Electric Power Engineering South China University of TechnologyGuangzhou 510640China Department of Electrical Engineering and Electronics The University of LiverpoolLiverpool L693GJUK

This paper develops a many-objective optimization model, which contains objectives representing the interests of the electricity and gas networks, as well as the distributed district heating and cooling units, to coordinate the benefits of all parties participated in the integrated energy system(IEs). In order to solve the many-objective optimization model efficiently, an improved objective reduction(IOR) approach is proposed, aiming at acquiring the smallest set of objectives. The IOR approach utilizes the spearman’s rank correlation coefficient to measure the relationship between objectives based on the Pareto-optimal front captured by the multi-objective group search optimizer with adaptive covariance and Lévy flights algorithm, and adopts various strategies to reduce the number of objectives gradually. simulation studies are conducted on an IEs consisting of a modified IEEE 30-bus electricity network and a 15-node gas network. The results show that the many-objective optimization problem is transformed into a bi-objective formulation by the IOR. Furthermore,our approach improves the overall quality of dispatch solutions and alleviates the decision making burden.

关键词： Integrated energy system Gas network Electricity network Many-objective optimization Objective reduction

hetero-deformation promoted strengthening and toughening in BCC rich eutectic and near eutectic high entropy alloys

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journal of Materials science & Technology 2023年第15期146卷 1-9页

作者： D.h.Chung j.Lee q.F.he Y.K.Kim K.R.Lim h.s.Kim Y.Yang Y.s.Na Department of special Alloys Extreme Materials Research InstituteKorea Institute of Materials ScienceChangwonThe Republic of Korea Department of Mechanical Engineering City University of Hong KongKowloon TongKowloonHong KongChina Graduate Institute of Ferrous Technology Pohang University of Science and TechnologyPohangThe Republic of Korea Center for heterogenic Metal Additive Manufacturing Pohang University of Science and TechnologyPohangThe Republic of Korea Department of Materials science and Engineering City University of Hong KongKowloon TongKowloonHong KongChina

heterostructured eutectic high-entropy alloys(EhEAs)have attracted significant attention owing to their novel properties,such as balanced combinations of strength and fracture ***,the toughening/strengthening mechanisms of these EhEAs have not been thoroughly *** this study,we developed a series of dual-phase Al_((18–2x))Co_(30)Cr_((11+x))Fe_((11+x))Ni_(3)0(x=-1,0,1)eutectic and neareutectic hEAs containing face-centered cubic(FCC)and body-centered cubic(BCC)*** the high amount of BCC,which is referred to as the brittle phase,newly developed EhEAs exhibited superior fracture ***,we discovered that a fully eutectic hEA exhibited further improvements in both yield stress and fracture toughness,outperforming our off-eutectic and other previously reported *** combining experiments and theoretical models,we demonstrated that the synergistic increase in both strength and toughness in our fully eutectic hEA was derived from the high hetero-deformationinduced(hDI)strengthening/toughening associated with a high misorientation angle at the grain/phase boundaries.

关键词： Eutectic high entropy alloy Fracture toughness heterogeneous structure hetero deformation induced strengthening Misorientation angle

Novel ternary Ag/CeVO_4/g-C_3N_4 nanocomposite as a highly efficient visible-light-driven photocatalyst

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journal of Advanced Ceramics 2018年第1期7卷 50-57页

作者： j.REN Y.Z.WU j.M.PAN X.h.YAN M.ChEN j.j.wang D.F.wang C.ZhOU q.wang X.N.ChENG school of Materials science and Engineering Jiangsu University Institute for Advanced Materials Jiangsu University Institute of Green Materials and Metallurgy Jiangsu University

The CeVO_4/graphitic C_3N_4 composites have exhibited much enhanced photocatalytic property for degrading methylene blue(MB) pollutant under visible light irradiation compared with single-phase g-C_3N_4 or CeVO_4. The composite s5 obtained from an optimized mass ratio(5%) of CeVO_4 to dicyanamide(DCDA) exhibits the highest photocatalytic activity. here, ternary Ag/CeVO_4/g-C_3N_4 composites denoted as X%Ag/s5 were prepared by an ultrasonic precipitation method to improve the photocatalytic property of s5. The TEM images show that CeVO_4 and Ag nanoparticles are well distributed on the layered g-C_3N_4, which agree well with the XRD results. The UV spectra show that the 7%Ag/s5 sample has the widest absorption range and the enhanced absorption intensity under visible light irradiation. The corresponding band gap of 7%Ag/s5(2.5 eV) is much lower than that of s5(2.65 eV). The corresponding k value of 7%Ag/s5 is much higher than those of g-C_3N_4 and CeVO_4. The degradation experiments for MB solution suggest that the 7%Ag/s5 sample has the optimal photocatalytic performance, which can degrade MB solution completely within 120 min. The enhanced photocatalytic property of the composites is ascribed to not only the effect of heterojunction structure, but also the surface plasma resonance effect of Ag nanoparticles.

关键词： g-C3N4 CeVO4 Ag nanocomposites photocatalytic performance

A FLOW sTREss MODEL FOR AZ61 MAGNEsIUM ALLOY

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Acta Metallurgica sinica(English Letters) 2004年第2期17卷 155-160页

作者： h.T.Zhou X.q.Zeng q.D wang W.j.Ding state Key Laboratory of Metal Matrix Composite,shanghai jiaotong University,shanghai 200030,China state Key Laboratory of Metal Matrix Composite Shanghai Jiaotong University Shanghai 200030 China

The flow stress behaviors of AZ61 alloy has been investigated at temperature rangefrom 523 to 673K with the strain rates of 0.001-1s^(-1). It is found that the averageactivation energy, strain rate sensitive exponent and stress exponent are different atvarious deformation conditions changing from 143.6 to 176.3kj/mol, 0.125 to 0.167and 6 to 8 respectively. A flow stress model for AZ61 alloy is derived by analyzingthe stress data based on hot compression test. It is demonstrated that the flow stressmodel including strain hardening exponent and strain softening exponent is suitableto predicate the flow stress. The prediction of the flow stress of AZ61 alloy has shownto be good agreement with the test data. The maximum differences of the peak stressescalculated by the model and obtained by experiment is less than 8%.

关键词： magnesium alloy flow stress model hot deformation straion softening

Effect of nitrogen on deposition and field emission properties of boron-doped micro-and nano-crystalline diamond films

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Nano-Micro Letters 2010年第3期2卷 154-159页

作者： L.A.Li s.h.Cheng h.D.Li q.Yu j.W.Liu X.Y.Lv state Key Laboratory of superhard Materials Jilin University

In this paper,we report the effect of nitrogen on the deposition and properties of boron doped diamond films synthesized by hot filament chemical vapor *** diamond films consisting of micro-grains(nano-grains) were realized with low(high) boron source flow rate during the growth *** transition of micro-grains to nano-grains is speculated to be strongly(weekly) related with the boron(nitrogen) flow *** grain size and Raman spectral feature vary insignificantly as a function of the nitrogen introduction at a certain boron flow *** variation of electron field emission characteristics dependent on nitrogen is different between microcrystalline and nanocrystalline boron doped diamond samples,which are related to the combined phase composition,boron doping level and texture *** is an optimum nitrogen proportion to improve the field emission properties of the boron-doped films.

关键词： Chemical vapor deposited diamond film Nitrogen effect Boron doping Microcrystalline Nanocrystalline Electron field emission

Recent progresses on designing and manufacturing of bulk refractory alloys with high performances based on controlling interfaces

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journal of Materials science & Technology 2020年第17期52卷 29-62页

作者： T.Zhang h.W.Deng Z.M.Xie R.Liu j.F.Yang C.s.Liu X.P.wang q.F.Fang Y.Xiong school of Physics and Electronic Engineering Guangzhou UniversityGuangZhou 510006China Key Laboratory of Materials Physics Institute of Solid State PhysicsChinese Academy of SciencesHefei 230031China state Key Laboratory of Environment Friendly Energy Materials West South University of Sciences and TechnologyMianYang 621010China

Refractory alloys such as tungsten and molybdenum based alloys with high strength,thermal/electrical conductivity,low coefficient of thermal expansion and excellent creep resistances are highly desirable for applications in nuclear facilities,critical components in aerospace and defense ***,the serious embrittlement limits the engineering usability of some refractory alloys.A lot of research results indicate that the performances of refractory alloys are closely related to the physical/chemical status,such as the interface dimension,interface type,interface composition of their grain boundaries(GBs),phase boundaries(PBs)and other interface *** paper reviewed the recent progress of simulations and experiments on interface design strategies that achieve high performance refractory *** strategies include GB interface purifying/strengthening,PB interface strengthening and PB/GB synergistic *** details are provided on the design/fabrication strategy such as GB interface controlling,PB interface controlling and synergistic control of multi-scaled *** corresponding performances such as the mechanical property,thermal conductivity,thermal load resistance,thermal stability,irradiation resistance,and oxidation resistance are reviewed in the aspect to the effect of *** addition,the relationships between these interfaces and material properties are ***,future developments and potential new research directions for refractory alloys are proposed.

关键词： Interface controlling Designing and manufacturing Refractory alloys structure and performance

sTUDY ON TEMPERATURE FIELD INDUCED IN hIGh FREqUENCY INDUCTION hEATING

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Acta Metallurgica sinica(English Letters) 2006年第3期19卷 190-196页

作者： h. shen Z.q. Yao Y.j. shi j. hu school of Mechanical Engineering Shanghai Jiaotong University Shanghai 200030 China

A mathematical model was established for the temperature field developed during high frequency induction heating （hFIh） by Maxwell＇s equations. It required solving the coupled equations of the electromagnetic and temperature fields. The numerical simudation was performed using FEMLAB. The comparison of the calculations using the proposed model with experimental results showed a very good correlation. The effects of the heating parameters in high frequency induction such as the distance between the plate and the coil, the applied current, the frequency, and the turns of the coil on the temperature profiles developed in the plate were also discussed using the established model.

关键词： high frequency induction temperature field numerical simudation

Tuning the morphologies of siC nanowires via the change of the Co_xsi_y melts

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Nano-Micro Letters 2010年第1期2卷 11-17页

作者： j.j.Chen Y.Pan W.h.Tang q.shi Department of Physics Center for Optoelectronics Materials and Devices Zhejiang Sci-Tech University Department of Materials science and Engineering Zhejiang University Key Laboratory of Advanced Textile Materials and Manufacturing Technology (Zhejiang sci-Tech University) Ministry of education

siC nanowires and siC/siO2 core-shell structural nanowires were synthesized via a simple thermal evaporation of Coxsiy melts at the temperature of 1500?C. The morphologies and yields of those siC nanowires can be tuned by altering the composition of Coxsiy. Nanowires obtained by thermal evaporation of Co si are composed of siC/siO2 core-shell nanostructures with lengths up to several hundreds of micrometers, diameters of 4050 nm, and the thickness of amorphous siO2 wrapping shell about 20 nm. siC nanowires prepared by thermal evaporation of Co si2 and Co2 si melt are found to be hexagonal-prism-shaped nanorods, and the diameter of those nanorods is about 150 nm and the length is about 10 microns. All the siC nanowires obtained possess [111] preferred growth direction with a high density stacking faults and twin defects. Taking into consideration the binary alloy diagram of Co si and the participation of oxygen, we propose the vapor-solid growth mechanism of siC nanowires and discuss the effect of the supersaturation of si O on the morphology and yields of siC nanowires.

关键词： silicon carbide Nanowires Morphology

TOTAL ENERGIEs AND ELECTRONIC sTRUCTUREs OF CO_3Ti AND hYDROGENIZED Co_3Ti

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Acta Metallurgica sinica(English Letters) 1998年第3期11卷 197-201页

作者： s.q.Duan s.j.Liu B.K.Ma Beijing Normal Univ Beijing China

Electronic structure calculations using the tighting-binding linear muffin-tin orbital (TB-LMTO) method have been performed for Co3Ti and its hydride CO3Ti. The computed values of lattice constants and bulk moduli agree with the experiment values. The theoritical excess enerpy and lattice staid due to hydrogen absorption consequently obtained hem the ab initio results indicate that h has the tendency to stay in Co3Ti and the ionicities of Co atomic spheres due to hydmpen absorption change from the canons to the ations. On the other hand, the changes of band structures due to hydrogenation are found to be remarkable.

关键词： total enerpy electronic structure hydrogenized Co3Ti