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Journal of Materials Science & Technology 2012年第7期28卷 666-672页

作者： S.q. Deng z.P. Xue Y.H. Yang q. Yang Y.L. Liu Department of Chemistry Jinan University Guangzhou 510632 China

Well dispersed and homogeneous Y2O2S：Sm3＋ hollow submicrospheres were successfully achieved by a template- free solvothermal method combining with a postcalcining process. The crystalstructure and particle morphology were investigated by the X-ray diffraction （XRD）, Fourier transform infrared （FT-IR） spectra, scanning and transmission electron microscopy （SEM and TEM）, respectively. A possible growth mechanism was proposed to reveal the formation process. Luminescence properties of the Y202S：Sm3＋ long-lasting phosphor were an- alyzed by measuring the excitation spectra, emission spectra, afterglow decay curve and thermoluminescence curve. The excitation spectra indicated that the phosphor could be excited effectively by the ultraviolet-light emitting diode （UV-LED） or blue LED, and the emission spectra showed that the phosphor could emit red light from 600 to 650 nm.

关键词： Yttrium oxysulfide Hollow submicrosphere Luminescence Long-lasting phosphor

EFFECT OF MODIFICATION ON CARBIDE GRANULATION AND ITS MECHANISM

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Acta Metallurgica Sinica(English Letters) 1999年第2期12卷 167-172页

作者： Wang, S.q. Jiang, q.C. Cui, X.H. He, z.M. Jilin Univ of Technology Changchun China

By the modification, network carbide is disconnected at 1100 degree C through uneven dissolution at higher energy places in carbide, where there is twin or lattice distortion, and is granulated at 1130 degree C through element diffusion. The stability of M//7C//3 carbide is decreased because of the modification reducing the segregation of Cr and Mo, thus the temperature, at which uneven dissolution of carbide commenced, is decreased. Also lattice distortion or defect such as twin in carbide is increased by the modification, which prompts widespread disconnections in carbide. In addition, the modification prompts element diffusion to accelerate the kinetics process of carbide granulation. (Edited author abstract) 6 Refs.

关键词： Carbides Chromium alloys Granulation Modification Morphology

KINETIC STUDY OF SPINEL LiMn_2O_4 SYNTHESIzED BY SOLID REACTION WITH SOFT-CHEMICAL METHOD

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Acta Metallurgica Sinica(English Letters) 2005年第4期18卷 512-518页

作者： C.q. Xu Y. W. Tian Y. C. zhai z.J. Guo z. q. Huang School of Materials and Metallurgy Northeastern University Shenyang 110004 China

The differential thermal analysis （DTA） curves were measured at different heating rates in flowing air for studying the synthesis of the spinel LiMn2O3 with Li2CO3 and MnO2, The reaction began at about 503K, and finished at about 873K. The apparent activation energy of Kissinger method was about ***^-1, the reaction orderwas 1.67, the frequency factor was 7.81×10^9, and therefore the dinetic epuation was dδ/dt=A·exp（- E/RT）·（1-δ）^n=7.81×10^9, exp（-122770/RT）·（l-δ）^1.67 . Coats-Redfem integral method was used to analyze the DTA curves of the samples at different heating rates, and the calculated apparent activation energy and frequency factor were 112. 13kJ· mol^-1 and 1.18 × 10^9, respectively, rather close to that of Kissinger method. X-ray diffraction （XRD） and scanning electron microscope （SEM） results shown that the synthesized LiMn2O3 possesses pure phase, regular shape and normal particle distribution.

关键词： lithium manganese oxides synthesized kinetics Kissinger method,Coats-Redfern integral method

Active{1121}and{1012}extension twinning in a WE43 Mg alloy

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Journal of Materials Science & Technology 2023年第13期144卷 93-101页

作者： W.q.Chen S.Deng X.J.zhao S.N.luo Key Laboratory of Advanced Technologies of Materials Ministry of EducationSouthwest Jiaotong UniversityChengdu 610031China The Peac Institute of Multiscale Sciences Chengdu 610031China

Deformation twinning in a WE43 alloy subjected to uniaxial compression at room temperature is ***{1121}and{1012}extension twinning is *** activation of{1121}twinning in a certain grain is influenced not only by its own Schmid factor,but also by that of the basal ***-twin interactions of the co-zone{1121}twin variants are commonly observed and systematically studied,including the crystallographic characteristics of the four typically observed twin-twin junctions(TTJs)and the associated twin-twin *** the quilted-looking TTJs formed by the interaction of co-zone{1012}twin variants,crossing-like TTJs of co-zone{1121}twin variants are observed and their formation mechanisms are ***-like TTJs are also formed by the interaction of{1121}and{10¯12}*** morphology and thickening rate of{1121}and{1012}twins vary markedly due to the difference in twinning *** needle-like{1121}twins thicken more slowly than the lenticular{1012}*** nucleation is observed on the previously formed{1121}twin boundary due to the relatively large strain concentration on such interface,while twin nucleation on{1012}twin boundary is rarely observed.

关键词： Mg alloy Plastic deformation Twinning Twin-twin interaction Twin-twin junction

An Analytical Solution of Melting around a Moving Elliptical Heat Source

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Journal of Thermal Science 1994年第1期3卷 23-27页

作者： W.z. Chen S.M. Cheng z. luo H.q. zhu(Huazhong University of Science and Technology,Wuhan 430074, China) 1. Huazhong University of Science and Technology 430074 Wuhan China

This paper studies the close-contact melting around a moving, horizontal elliptical heat source thatmelts its way through a phase change material under its own weight. The heat source velocity andthe volume of the material melted are obtained by analysis. The effects of compression coefficient andtemperature distribution in the melt are investigated. The results include that for melting around amoving cylindrical heat source.

关键词： phase change close contact melting moving heat source analytical solution

Influencing mechanism of pre-existing nanoscale Al5Fe2 phase on Mg-Fe interface in friction stir spot welded Al-free zK60-q235 joint

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Journal of Materials Science & Technology 2020年第7期42卷 220-228页

作者： R.z.Xu q.Yang D.R.Ni B.L.Xiao C.z.Liu z.Y.Ma Institute of Metal Research Chinese Academy of SciencesShenyang110016China College of Material Science and Engineering Shenyang Aerospace UniversityShenyang110136China Department of Materials Science and Engineering University of Illinois at Urbana-Champaign1304 W Green StUrbanaIL61801United States Fredrick Seitz Materials Research Laboratory University of Illinois at Urbana-Champaign104 S Goodwin AveUrbanaIL61801United States

Al-free zK60 magnesium (Mg) alloy sheet was selected as substrate material of Mg-steel pinless friction stir spot welding (FSSW), avoiding the effect of the Al element in the substrate on the alloying reaction of Mg-iron (Fe) interface. The sound FSSW joint of zK60 Mg alloy and q235 steel with a hot-dipped aluminum (Al)-containing zinc (zn) coating was successfully realized. The detailed microstructural examinations proved that Al5Fe2 phase at the Mg-Fe interface came from the pre-existing Al5Fe2 phase in the coating and acted as the transition layer for promoting the metallurgical bonding of Mg and Fe. The interfaces with well-matched lattice sites among Fe, Al5Fe2 and Mg were formed during FSSW. A low energy interface with good match of lattice sites ((002)Al5Fe2//(110)Fe, [110]Al5Fe2//[113]Fe) between Al5Fe2 and Fe was identified. For the interface between Al5Fe2 and Mg, an orientation relationship of (622)Al5Fe2//(3112)Mgand[158]Al5Fe2//[2423]Mg was observed. The tensile-shear load of the zK60-steel joint could reach 4.6 kN. Moreover, the joint fracture occurred at the interface between the Al5Fe2 layer and the Mg alloy substrate, suggesting the brittle fracture characteristic.

关键词： Dissimilar welding Friction stir spot welding Magnesium alloys Steels zinc coating

Tizr-base Bulk Metallic Glass with over 50 mm in Diameter

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Journal of Materials Science & Technology 2010年第6期26卷 481-486页

作者： M. q. Tang H.F. zhang z. W. zhu H.M. Fu A.M. Wang H. Li z.q. Hu Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences 72Wenhua Road Shenyang 110016 China

Low-cost Tizr-base bulk metallic glasses （BMGs）（Ti36.1zr33.2Ni5.8Be24.9）100-xCux （x=5, 7 and g） with a maximum size of over 50 mm in diameter were developed by optimizing the alloy composition. The idea is initiated by selecting a particular microstructure comprising primary β-Ti dendrite and amorphous phase. Afterwards, based on this composition of amorphous phase, a class of Tizr-base bulk metallic glasses was designed step by step to reach the optimum composition range. The glass transition temperature （Tg）, initial crystallization temperature （Tx） and width of supercooled region （AT） of （***33.2Nis.8Be24.9）91Cu9 BMG are 611, 055 and 44 K, respectively. The （Ti36.1zr33.2Ni5.8Be24.9）91Cu9 BMG exhibits low density of 5.541 g·cm-3 and high compressive fracture strength of 1800 MPa, which promises the potential application as structural materials.

关键词： Tizr-base alloy Bulk metallic glass (BMG) Fracture strength

Soft computing approach for prediction of surface settlement induced by earth pressure balance shield tunneling

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Underground Space 2021年第4期6卷 353-363页

作者： W.G.zhang H.R.Li C.z.Wu Y.q.Li z.q.Liu H.L.Liu Key Laboratory of New Technology for Construction of Cities in Mountain Area Chongqing UniversityChongqing 400045China National Joint Engineering Research Center of Geohazards Prevention in the Reservoir Areas Chongqing UniversityChongqing 400045China School of Civil Engineering Chongqing UniversityChongqing 400045China Norwegian Geotechnical Institute(NGI) Sognsveien 720855 OsloNorway

Estimating surface settlement induced by excavation construction is an indispensable task in tunneling,particularly for earth pressure balance(EPB)shield *** this study,predictive models for assessing surface settlement caused by EPB tunneling were established based on extreme gradient boosting(XGBoost),artificial neural network,support vector machine,and multivariate adaptive regression *** from three tunnel construction projects in Singapore were used,with main input parameters of cover depth,advance rate,earth pressure,mean standard penetration test(SPT)value above crown level,mean tunnel SPT value,mean moisture content,mean soil elastic modulus,and grout *** performances of these soft computing models were evaluated by comparing predicted deformation with measured *** demonstrate the acceptable accuracy of the model in predicting ground settlement,while XGBoost demonstrates a slightly higher *** addition,the ensemble method of XGBoost is more computationally efficient and can be used as a reliable alternative in solving multivariate nonlinear geo-engineering problems.

关键词： EPB Surface settlement Soft computing XGBoost Multivariate adaptive regression spline

Recent development of chemically complex metallic glasses: from accelerated compositional design, additive manufacturing to novel applications

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Materials Futures 2022年第1期1卷 9-31页

作者： J Y zhang z q zhou z B zhang M H Park q Yu z Li J Ma A D Wang H G Huang M Song B S Guo q Wang Y Yang Department of Mechanical Engineering College of EngineeringCity University of Hong KongKowloon TongKowloonHong KongPeople’s Republic of China Shenzhen Key Laboratory of High Performance Nontraditional Manufacturing College of Mechatronics and Control EngineeringShenzhen UniversityShenzhenGuangdong 518060People’s Republic of China School of Materials Science and Engineering Dongguan University of TechnologyDongguanGuangdong 523808People’s Republic of China Institute of Materials China Academy of Engineering PhysicsJiangyouSichuan 621907People’s Republic of China State Key Laboratory of Powder Metallurgy Central South UniversityChangshaHunan 410083People’s Republic of China Institute of Advanced Wear&Corrosion Resistant and Functional Materials Jinan UniversityGuangzhouGuangdong 510632People’s Republic of China Institute of Materials Laboratory for MicrostructuresShanghai UniversityShanghai 200444People’s Republic of China Department of Materials Science and Engineering College of EngineeringCity University of Hong KongKowloon TongKowloonHong KongPeople’s Republic of China Department of Advanced Design and System Engineering College of EngineeringCity University of Hong KongKowloon TongKowloonHong KongPeople’s Republic of China

Metallic glasses(MGs)or amorphous alloys are an important engineering material that has a history of research of about 80–90 *** different fast cooling methods were developed for multi-component MGs between 1960s and 1980s,1990s witnessed a surge of research interest in the development of bulk metallic glasses(BGMs).Since then,one central theme of research in the metallic-glass community has been compositional design that aims to search for MGs with a better glass forming ability,a larger size and/or more interesting properties,which can hence meet the demands from more important *** this review article,we focus on the recent development of chemically complex MGs,such as high entropy MGs,with new tools that were not available or mature yet until recently,such as the state-of-the-art additive manufacturing technologies,high throughput materials design techniques and the methods for big data analyses(*** learning and artificial intelligence).We also discuss the recent use of MGs in a variety of novel and important applications,from personal healthcare,electric energy transfer to nuclear energy that plays a pivotal role in the battle against global warming.

关键词： metallic glasses amorphous alloys alloy design additive manufacturing machine learning high throughput materials design