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comparison of microstructure and mechanical behavior of ti-35Nb manufactured by laser powder bed fusion from elemental powder mixture and prealloyed powder

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Journal of Materials science & technology 2022年第10期105卷 1-16页

作者： J.c.wang y.J.liu s.X.liang y.s.zhang l.Q.wang t.B.sercombe l.c.zhang school of Engineering Edith Cowan University270 Joondalup DriveJoondalupPerthWA 6027Australia school of Engineering M050The University of Western Australia35 Stirling HighwayCrawleyPerthWA 6009Australia Northwest Institute for Nonferrous Metal Research Xi’an 710016China state Key laboratory of Metal Matrix composites School of Material Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Although different types of powder feedstock are used for additive manufacturing via laser powder bed fusion(l-PBF),limited work has attempted to directly compare the microstructure and mechanical behavior of components manufactured from those powder *** work investigated the microstructure,phase composition,melt pool morphology,and mechanical properties of a prealloyed ti-35Nb alloy manufactured using l-PBF and compared these to their counterparts produced from elemental powder *** samples manufactured from the powder mixture are composed of randomly distributed undissolved Nb in theα/βmatrix,resulting from the unstable melt pool during the melting of the powder *** contrast,parts produced from prealloyed powder display a homogeneous microstructure withβandαphases,owing to the full melting of prealloyed powder,therefore,a more stable melt pool to achieve a homogeneous *** ti-35Nb manufactured from prealloyed powder exhibits large tensile ductility(about 10 times that of the counterparts using mixed powder),attributed to the high homogeneity in microstructure and chemical composition,strong interface bonding,relatively low oxygen content,and the existence of a large amount ofβ*** work sheds insights into understanding the effect of powder feedstock on the melt pool stability therefore the microstructure and mechanical behavior of the resultant parts.

关键词： titanium-niobium Powder bed fusion Additive manufacturing Melt pool stability Microstructure Mechanical properties

MIcROBRIDGE tEstING OF yOUNG's MODUlUs AND REsIDUAl stREss OF NIcKEl FIlM ElEctROPlAtED ON sIlIcON wAFER

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Acta Metallurgica sinica(English letters) 2004年第3期17卷 247-254页

作者： y.Zhou c.s.yang J.A. chen G.F. Ding l. wang M.J wang y.M zhang t.h zhang Key laboratory for thin Film and Microfabrication of Ministry of Education Research Institute of Micro/Nanometer Science and Technology Shanghai Jiaotong University Shanghai 200030 China state Key laboratory of Nonlinear Mechanics (lNM) Institute of Mechanics The Chinese Academy of Sciences Beijing 100080 China.

Microbridge testing is used to measure the young's modulus and residual stresses of metallic *** film microbridges with widths of several hundred microns are fabricated by Microelectromechanical *** order to measure the mechanical properties of nickel film microbridges,special shaft structure is designed to solve the problem of getting the load--deflection curves of metal film microbridge by Nanoin--denter XP system with normal Berkovich *** analysis of the micro--bridge load--deflection curve is proposed to evaluate the young's modulus and residual stress of the films *** calculated results based on the experimental measurements show that the average young's modulus and residual stress are around 190GPa and 175MPa respectively,while the young's modulus measured by Nano-hardness method on nickel film with silicon substrate is 186.8±7.34GPa.

关键词： nickel film microbridge MEMs mechanical property loadeflection measurement

Effect of trace Ni addition on microstructure,mechanical and corrosion properties of the extruded Mg-Gd-y-Zr-Ni alloys for dissoluble fracturing tools

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Journal of Magnesium and Alloys 2021年第5期9卷 1649-1660页

作者： J.wang t.li h.X.li y.Z.Ma K.N.Zhao c.l.yang J.s.zhang state Key laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China Department of Petroleum Equipment of RIPED PetroChinaBeijing 100083China state Key laboratory of solidification Processing Northwestern Polytechnical UniversityXi'an 710072China

Magnesium alloys,a novel functional material for the fabrication of fracturing tools,are being paid more and more attentions recently due to their relatively high mechanical properties and fast dissolubility ability after *** this study,the novel extruded Mg-10Gd-3y-0.3Zr-xNi alloys will be reported and their microstructure,mechanical and corrosion behaviors will be also *** results show that Ni contents influence phase precipitation *** adding 0.2 wt%Ni,a large amount of Zr_(7)Ni_(10)phases will be precipitated insidesα-Mg matrix,directly leading to degradation of strength and large corrosion *** further increasing Ni contents,the precipitation phases can be changed from Mg_(5)RE to 18R-lPsO structure,resulting in higher mechanical properties and faster corrosion ***,adding Ni element also change the texture orientation by influencing the precipitation behavior of the *** alloys invented in this paper have attained the highest compressive and tensile properties among all the reported dissoluble magnesium *** work is beneficial in understanding the role of Ni in the magnesium alloys and provides more materials alternatives for the fabrication of dissoluble fracturing tools.

关键词： Dissoluble magnesium alloys Microstructure Mechanical properties corrosion behaviors Fracturing tools

Applicability of large-ion lithophile and high field strength element basalt discrimination diagrams

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International Journal of Digital Earth 2018年第7期11卷 752-760页

作者： X.l.liu Q.zhang w.c.li F.c.yang y.Zhao Z.li s.t.Jiao J.R.wang N.zhang s.s.wang w.F.chen Z.J.Pan J.yang X.l.Du Faculty of land and Resource Engineering Kunming University of Science and TechnologyKunmingPeople’s Republic of China Institute of Geology and Geophysics Chinese Academy of SciencesBeijingPeople’s Republic of China chengdu Geological survey center of china Geological survey ChengduPeople’s Republic of China school of Earth science Lanzhou UniversityLanzhouPeople’s Republic of China

Basalt discriminant diagrams have been used to identify the tectonic setting of basaltic magmatism since the 1970s and have played an important role in reconstructing paleotectonic ***,the significant increase in the availability of geochemical data has led to a reassessment of these diagrams,suggesting that some of the tectonic settings indicated by these diagrams are not ***,we use a database of global ocean island basalt(OIB),mid-ocean ridge basalt(MORB),and island arc basalt(IAB)geochemistry to propose a series of new tectonic discriminant diagrams based on the ratios of large-ion lithophile elements(lIlEs)to high field strength elements(hFsEs).these new diagrams indicate that the lIlE can be used to differentiate OIB,MORB,and IAB samples,meaning that lIlE/hFsE ratios can discriminate between these basalts that form in different tectonic *** new diagrams can correctly assign samples to OIB,MORB,and IAB categories more than 85%of the time,with the discrimination between OIB and MORB having an accuracy of slightly less than 85%.

关键词： Basalt lIlE hFsE discrimination diagram geochemistry

the lobster Eye Imager for Astronomy Onboard the sAtech-01 satellite

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Research in Astronomy and Astrophysics 2023年第9期23卷 66-78页

作者： Z.X.ling X.J.sun c.zhang s.l.sun G.Jin s.N.zhang X.F.zhang J.B.chang F.s.chen y.F.chen Z.w.cheng w.Fu y.X.han h.li J.F.li y.li Z.D.li P.R.liu y.h.lv X.h.Ma y.J.tang c.B.wang R.J.Xie y.l.Xue A.l.yan Q.zhang c.y.Bao h.B.cai h.Q.cheng c.Z.cui y.F.Dai D.w.Fan h.B.hu J.w.hu M.h.huang Z.Q.Jia c.c.Jin D.y.li J.Q.li h.y.liu M.J.liu y.liu h.w.Pan y.l.Qiu M.sugizaki h.sun w.X.wang y.l.wang Q.y.wu X.P.Xu y.F.Xu h.N.yang X.yang B.zhang M.zhang w.D.zhang Z.zhang D.h.Zhao X.Q.cong B.w.Jiang l.h.li X.B.Qiu J.N.sun D.t.su J.wang c.wu Z.Xu X.M.yang s.K.zhang Z.zhang N.zhang y.F.Zhu h.y.Ban X.Z.Bi Z.M.cai w.chen X.chen y.h.chen y.cui X.l.Duan Z.G Feng y.Gao J.w.he t.he J.J.huang F.li J.s.li t.J.li t.t.li h.Q.liu l.liu R.liu s.liu N.Meng Q.shi A.t.sun y.M.wang y.B.wang h.c.wu D.X Xu y.Q yang y.yang X.s.yu K.X.zhang y.l.zhang y.h.zhang y.t.zhang h.Zhou X.c.Zhu J.s.cheng l.Qin l.wang Q.l.wang M.Bai R.l.Gao Z.Ji y.R.liu F.l.Ma y.J.shi J.su y.y.tan J.Z.tong h.t.Xu c.B.Xue G.F.Xue w.yuan National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China school of Astronomy and space science University of Chinese Academy of SciencesBeijing 100049China shanghai Institute of technical Physics Chinese Academy of SciencesShanghai 200083China North Night Vision technology co. LTDNanjing 211106China Institute of high Energy Physics Chinese Academy of SciencesBeijing 100049China science and technology on low-light-level Night Vision laboratory Xi'an 710065China Innovation Academy for Microsatellites Chinese Academy of SciencesShanghai 201204China Institute of Electrical Engineering Chinese Academy of ScienceBeijing 100190China National space science center Chinese Academy of ScienceBeijing 100190China

the lobster Eye Imager for Astronomy(lEIA),a pathfinder of the wide-field X-ray telescope of the Einstein Probe mission,was successfully launched onboard the sAtech-01 satellite of the chinese Academy of sciences on2022 July *** this paper,we introduce the design and on-ground test results of the lEIA *** stateof-the-art Micro-Pore Optics(MPO),a wide field of view of 346 square degrees(18.6°×18.6°)of the X-ray imager is *** optical assembly composed of 36 MPO chips is used to focus incident X-ray photons,and four large-format complementary metal-oxide semiconductor(cMOs)sensors,each of size 6 cm×6 cm,are used as the focal plane *** instrument has an angular resolution of 4’-8’(in terms of FwhM)for the central focal spot of the point-spread function,and an effective area of 2-3 cm^(2) at 1 keV in essentially all the directions within the field of *** detection passband is 0.5-4 keV in soft X-rays and the sensitivity is2-3×10^(-11) erg s^(-1) cm^(-2)(about 1 millicrab)with a 1000 s *** total weight of lEIA is 56 kg and the power is 85 *** satellite,with a design lifetime of 2 yr,operates in a sun-synchronous orbit of 500 km with an orbital period of 95 *** is paving the way for future missions by verifying in flight the technologies of both novel focusing imaging optics and cMOs sensors for X-ray observation,and by optimizing the working setups of the instrumental *** addition,lEIA is able to carry out scientific observations to find new transients and to monitor known sources in the soft X-ray band,albeit with limited useful observing time available.

关键词： instrumentation detectors-space vehicles instruments-telescopes-X-rays genera

Epitaxial growth and air-stability of monolayer cu2te

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chinese Physics B 2020年第1期29卷 99-102页

作者： K Qian l Gao h li s zhang J h yan c liu J O wang t Qian h Ding y y zhang X lin s X Du h-J Gao Institute of Physics&University of chinese Academy of sciences Chinese Academy of SciencesBeijing 100190China Institute of high Energy Physics Chinese Academy of SciencesBeijing 100049China cAs center for Excellence in topological Quantum computation University of Chinese Academy of SciencesBeijing 100190China

A new two-dimensional atomic crystal, monolayer cuprous telluride（cu2te） has been fabricated on a graphenesi c（0001） substrate by molecular beam epitaxy（MBE）. the low-energy electron diffraction（lEED） characterization shows that the monolayer cu2te forms ■ superstructure with respect to the graphene substrate. the atomic structure of the monolayer cu2te is investigated through a combination of scanning tunneling microscopy（stM） experiments and density functional theory（DFt） calculations. the stoichiometry of the cu2te sample is verified by x-ray photoelectron spectroscopy（XPs） measurement. the angle-resolved photoemission spectroscopy（ARPEs） data present the electronic band structure of the sample, which is in good agreement with the calculated results. Furthermore, air-exposure experiments reveal the chemical stability of the monolayer cu2te. the fabrication of this new 2D material with a particular structure may bring new physical properties for future applications.

关键词： cuprous telluride(cu2te) scanning tunneling microscopy(stM) density functional theory(DFt) chemical stability

Embedding laser-generated cdte nanocrystals into ultrathin ZnIn_(2)s_(4) nanosheets with sulfur vacancies for boosted photocatalytic h_(2) evolution

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Journal of Materials science & technology 2023年第35期166卷 113-122页

作者： Z.G.tai G.t.sun X.h.zhang X.B.yang t.wang Z.y.Fang Q.ye l.c.Jia h.Q.wang state Key laboratory of solidification Processing Center for Nano Energy MaterialsSchool of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Research&Development Institute of Northwestern Polytechnical University in shenzhen Shenzhen 518063China school of Materials science and Engineering Shaanxi Normal UniversityXi’an 710119China

to suppress the inner charge recombination and inject vast electrons,cdte nanocrystals are embedded into ultrathin ZnIn_(2)s_(4) nanosheets to construct ZnIn_(2)s_(4)/cdte heterostructures,where the nanocrystals are generated by a laser irradiation *** optimal ZnIn_(2)s_(4)/cdte heterojunction exhibits an excellent catalytic activity of 24.3 mmol/h/g,which is relatively high among the ZnIn_(2)s_(4)-based photocatalysts with-out noble *** enhancement is ascribed to a win-win mechanism of nanoscale heterojunctions and sulfur *** strong electron coupling effect,which is verified by density functional the-ory(DFt)calculations,impels the photo-generated electrons transfer from cdte to ZnIn_(2)s_(4),boosting the charge ***,the sulfur vacancies existing in ZnIn_(2)s_(4) can capture photoelectrons and act as active sites,facilitating the h_(2) generation *** addition,the ZnIn_(2)s_(4) base and the ZnIn_(2)s_(4)/cdte heterojunction also possess an evident photothermal effect and renewable cycle phenomena,enhancing the photocatalytic *** research provides new insights into the regulation of charge transfer through embedding nanocrystals.

关键词： Photocatalysis hydrogen evolution laser irradiation heterostructure sulfur vacancies

two-stage double peaks ageing and its effect on stress corrosion cracking susceptibility of Al-Zn-Mg alloy

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Journal of Materials science & technology 2018年第7期34卷 1250-1257页

作者： y.l.wang h.c.Jiang Z.M.li D.s.yan D.zhang l.J.Rong cAs Key laboratory of Nuclear Materials and safety Assessment Institute of Metal Research Chinese Academy of Sciences school of Materials science and Engineering University of Science and Technology of China

Different artificial two-stage ageing behaviors and their effect on stress corrosion cracking （scc） susceptibility of AI-Zn-Mg alloy have been investigated. the experimental results show that two hardness peaks present on the second-stage ageing-hardening curve when the first-stage ageing is dealt with comparatively lower temperature than the conventional one. the first peak is caused by dispersive and evenly distributed G.P. zones, while η ′phases and coarsened G.P. zones contribute to the second peak. tensile strength of experimental alloy raises 9.6% （33.2 MPa） and scc susceptibility decreases 38.9% by applying the second peak ageing regime instead of conventional t73. AI-Zn-Mg alloy obtains high strength and scc resistance due to its finely dispersive matrix precipitates （MPts）, coarsened and discontinuous grain boundary precipitates （GBPs）, as well as the narrow precipitate free zone （PFZ） in the second peak ageing condition. 2017 Published by Elsevier ltd on behalf of the editorial office of Journal of Materials science ＆ technology.

关键词： Al-Zn-Mg alloy two-stage ageing Double peaks ageing stress corrosion cracking (scc) susceptibility Grain boundary precipitates (GBPs)

New progress of the miniaturized microwave ion source at Peking University

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Radiation Detection technology and Methods 2023年第4期7卷 545-549页

作者： s.X.Peng t.h.Ma w.B.wu B.J.cui A.l.zhang y.X.Jiang Z.y.guo J.E.chen state Key laboratory of Nuclear Physics and technology and Institute of heavy Ion Physics Peking UniversityBeijingChina state Key laboratory of Particle Detection and Electronics Department of Modern PhysicsUniversity of Science and Technology of ChinaHefei230026China

the generation of plasma in a microwave ion source involves confining electrons using a static magnetic field and energizing them with an electromagnetic field that transmitted into the plasma ***,according to electromagnetics theory,there is always a cut-off size in circular wave guides for a given *** a 2.45 Ghz microwave,this dimension is 72 mm,which should theoretically prevent transmission of the microwave into the discharge chamber and no plasma can be *** 2006 Peking University(PKU)has successfully developed a series of permanent magnet 2.45 Ghz microwave ion sources(PKU PMEcRs)with a discharge chamber less than 50 mm,capable of delivering tens of mA beams for *** explain this anomalous phenomenon,a hybrid discharge heating(hDh)mode that combines surface wave plasma and electron cyclotron heating has been *** hDh mode not only successfully explains PKU PMEcRs,but also predicts that the optimized inner diameter of the plasma chamber is 24 mm,which is confirmed by experiments involving different liners in the miniaturized microwave ion source.

关键词： Miniaturized 2.45 Ghz EcR source hybrid discharge mode hydrogen plasma