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Recent advancements in thermal conductivity of magnesium alloys

journal of Magnesium and Alloys 2024年第5期12卷 1687-1708页

作者： Hao Lv jun Tan Qian Yuan Fanglei Wang Yunxuan Zhou Quan Dong Aitao Tang jürgen eckert Bin jiang Fusheng Pan National Engineering Research Center for Magnesium Alloys College of Materials Science and EngineeringChongqing UniversityChongqing 400044China National Key Laboratory of Advanced Casting Technologies Chongqing UniversityChongqing 400044China Department of Materials Science Chair of Materials PhysicsMontanuniversität LeobenJahnstraße 12Leoben A-8700Austria Erich Schmid Institute of Materials Science Austrian Academy of SciencesJahnstraße 12Leoben A-8700Austria

As highly integrated circuits continue to advance,accompanied by a growing demand for energy efficiency and weight reduction,materials are confronted with mounting challenges pertaining to thermal conductivity and lightweight *** virtue of numerous intrinsic mechanisms,as a result,the thermal conductivity and mechanical properties of the Mg alloys are often inversely related,which becomes a bottleneck limiting the application of Mg *** on several effective modification methods to improve the thermal conductivity of Mg alloys,this paper describes the law of how they affect the mechanical properties,and clearly indicates that peak aging treatment is one of the best ways to simultaneously enhance an alloy's thermal conductivity and mechanical *** the most frequently used Mg alloy,cast alloys exhibit substantial potential for achieving high thermal ***,recent reports indicate that hot deformation can significantly improve the mechanical properties while maintaining,and potentially slightly enhancing,the alloy's thermal *** presents a meaningful way to develop Mg alloys for applications in the field of small-volume heat dissipation components that require high *** comprehensive review begins by outlining standard testing and prediction methods,followed by the theoretical models used to predict thermal conductivity,and then explores the primary influencing factors affecting thermal *** review summarizes the current development status of Mg alloys,focusing on the quest for alloys that offer both high thermal conductivity and high *** concludes by providing insights into forthcoming prospects and challenges within this field.

关键词： Mg alloy Thermal conductivity Mechanical properties Solute atom Second phase

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Selective Laser Melting of Al-7Si-0.5Mg-0.5Cu:Effect of Heat Treatment on Microstructure Evolution,Mechanical Properties and Wear Resistance

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Acta Metallurgica Sinica(English Letters) 2022年第3期35卷 389-396页

作者： Pei Wang Sijie Yu jaskarn Shergill Anil Chaubey jürgen eckert Konda Gokuldoss Prashanth Sergio Scudino Additive Manufacturing Institute College of Mechatronics and Control EngineeringShenzhen UniversityShenzhen 518060China Institute for Complex Materials IFW DresdenHelmholtzstraBe 2001069 DresdenGermany Institute of Minerals and Materials Technology(IMMT) Bhubaneshwar 751013OrissaIndia Erich Schmid Institute of Materials Science Austrian Academy of SciencesJahnstraBe 128700 LeobenAustria Department of Materials Science Chair of Materials PhysicsMontanuniversitat LeobenJahnstraBe 128700 LeobenAustria Department of Mechanical and Industrial Engineering Tallinn University of TechnologyEhitajete tee 519086 TallinnEstonia CBCMT School of Mechanical EngineeringVellore Institute of TechnologyVellore.Tamil Nadu 632014India Adjunct With National University of Science and Technology aMISi Sa Leninsky Prosp..4.119049 MoscowRussia

Al-7Si-0.5Mg-0.5Cu alloy specimens have been fabricated by selective laser melting(SLM).In this study,the effects of solution treatment,quenching,and artifi cial aging on the microstructural evolution,as well as mechanical and wear properties,have been *** as-prepared samples show a heterogeneous cellular microstructure with two different cell sizes composed ofα-Al and Si *** solution-treated and quenched(SQ)heat treatment,the cellular microstructure disappears,and coarse and lumpy Si phase precipitates and a rectangular Cu-rich phase were *** aging after solution-treated and quenched(SQA)heat treatment causes the formation of nanosized Cu-rich *** asprepared SLMs sample has good mechanical properties and wear resistance(compressive yield strength:215±6 MPa and wear rate 2×10^(-13)m^(3)/m).The SQ samples with lumpy Si particles have the lowest strength of 167±13 MPa and the highest wear rate of 6.18×10^(1-13)m^(3)/*** formation of nanosized Cu-rich precipitates in the SQA samples leads to the highest compressive yield strength of 233±6 MPa and a good wear rate of 5.06×10^(-13)m^(3)/m.

关键词： Selective laser melting Al-Si-Cu-Mg alloy Heat treatment Microstructure Mechanical properties Wear properties

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Experimental and theoretical studies on two-dimensional vanadium carbide hybrid nanomaterials derived from V_(4)AlC_(3) as excellent catalyst for MgH_(2)

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journal of Magnesium and Alloys 2023年第10期11卷 3790-3799页

作者： Zhiqiang Lan Huiren Liang Xiaobin Wen jiayang Hu Hua Ning Liang Zeng Haizhen Liu jun Tan jürgen eckert jin Guo Guangxi Novel Battery Materials Research Center of Engineering Technology Guangxi Colleges and Universities Key Laboratory of Novel Energy Materials and Related TechnologySchool of Physical Science and TechnologyGuangxi UniversityNanning 530004PR China College of mathematics and Physics Guangxi Minzu UniversityNanning 530006PR China College of Materials Science and Engineering Chongqing UniversityChongqing 400044PR China Erich Schmid Institute of Materials Science Austrian Academy of SciencesJahnstraße 12Leoben A-8700Austria Department Materials Physics Montanuniversität LeobenJahnstraße 12Leoben A-8700Austria National University of Science and Technology«MISiS» LeninskyProsp.4Moscow 119049Russia

Hydrogen is considered one of the most ideal future energy *** safe storage and convenient transportation of hydrogen are key factors for the utilization of hydrogen *** the current investigation,two-dimensional vanadium carbide(VC) was prepared by an etching method using V_(4)AlC_(3) as a precursor and then employed to enhance the hydrogen storage properties of MgH_(2).The studied results indicate that VC-doped MgH_(2) can absorb hydrogen at room temperature and release hydrogen at 170℃. Moreover,it absorbs 5.0 wt.%of H_(2) within 9.8 min at 100℃ and desorbs 5.0 wt.% of H_(2) within 3.2 min at 300℃.The dehydrogenation apparent activation energy of VC-doped MgH_(2) is 89.3 ± 2.8 kj/mol,which is far lower than that of additive-free MgH_(2)(138.5 ± 2.4 kj/mol),***-initio simulations showed that VC can stretch Mg-H bonds and make the Mg-H bonds easier to break,which is responsible for the decrease of dehydrogenation temperature and conducive to accelerating the diffusion rate of hydrogen atoms,thus,the hydrogen storage properties of MgH_(2) are remarkable improved through addition of VC.

关键词： MgH_2 Two-dimensional Hydrogen storage material Density functional theory

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Mechanical behavior and deformation mechanism of shape memory bulk metallic glass composites synthesized by powder metallurgy

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journal of Materials Science & Technology 2022年第19期114卷 42-54页

作者： Tianbing He Tiwen Lu Daniel Sopu Xiaoliang Han Haizhou Lu Kornelius Nielsch jürgen eckert Nevaf Ciftci Volker Uhlenwinkel Konrad Kosiba Sergio Scudino Leibniz IFW Dresden Institute for Complex MaterialsHelmholtzstraße 2001069 DresdenGermany Guangdong Key Laboratory for Advanced Metallic Materials Processing South China University of TechnologyGuangzhou 510640China Erich Schmid Institute of Materials Science Austrian Academy of SciencesJahnstraße 12Leoben A-8700Austria Leibniz IFW Dresden Institute for Metallic MaterialsHelmholtzstraße 2001069 DresdenGermany TU Dresden Institute of Materials Science01062 DresdenGermany TU Dresden Institute of Applied Physics01062 DresdenGermany Department Materials Physics Montanuniversität LeobenJahnstraße 12A-8700 LeobenAustria Leibniz Institute for Materials Engineering IWT 28359 BremenGermany University of Bremen Faculty of Production Engineering28359 BremenGermany

The synthesis of martensitic or shape-memory bulk metallic glass composites(BMGCs)via solidification of the glass-forming melts requires the meticulous selection of the chemical composition and the proper choice of the processing parameters in order to ensure that the glassy matrix coexists with the desired amount of austenitic ***,a relatively limited number of such systems,where austenite and glassy matrix coexist over a wide range of compositions,is ***,we study the effective-ness of powder metallurgy as an alternative to solidification for the synthesis of shape memory ***_(48)Cu_(36)Al_(8)Ag_(8)matrix composites with different volume fractions of Ni_(50.6)Ti_(49.4)are fabricated using hot pressing and their microstructure,mechanical properties and deformation mechanism are investigated employing experiments and *** results demonstrate that shape-memory BMGCs with tun-able microstructures and properties can be synthesized by hot *** phase stability of the glass and austenitic components across a wide range of compositions allows us to examine fundamental as-pects in the field of shape memory BMGCs,including the effect of the confining stress on the martensitic transformation exerted by the glassy matrix,the contribution of each phase to the plasticity and the mechanism responsible for shear band *** present method gives a virtually infinite choice among the possible combinations of glassy matrices and shape memory phases,expanding the range of accessible shape memory BMGCs to systems where the glassy and austenitic phases do not form simul-taneously using the solidification route.

关键词： Metallic glass composites Niti alloys Mechanical properties Shear bands Martensitic transformation

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Enhanced mechanical performance of gradient-structured CoCrFeMnNi high-entropy alloys induced by industrial shot-blasting

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Rare Metals 2023年第3期42卷 982-993页

作者： Ming-Zhi Zhang Kun Zhang Kai-Kai Song Xiao-Yu Zou Wei-Dong Song Ke-Feng Li Li-Na Hu Ze-Qun Zhang jürgen eckert Shenzhen Research Institute of Shandong University Shenzhen 518057China CAS Key Laboratory of Microgravity(National Microgravity Laboratory) Institute of MechanicsChinese Academy of SciencesBeijing100190China State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China School of Mechanical Electrical and Information EngineeringShandong UniversityWeihai 264209China Guangdong Institute of Materials and Processing Guangdong Academy of SciencesGuangzhou 510650China Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials(Ministry of Education) Shandong UniversityJinan 250061China Erich Schmid Institute of Materials Science Austrian Academy of SciencesLeoben 8700Austria Department of Materials Science Montanuniversitat LeobenLeoben 8700Austria

In this study,CoCrFeMnNi high-entropy alloys(HEAs)with a surface gradient nanostructure were produced using industrial shot blasting,which improved their mechanical properties compared to the untreated *** severely plastically deformed(SPD)surface layer had a multi-scale hierarchical structure with a high density of stacking faults,deformation nanotwins,and amorphous *** depth of the SPD layer steadily increased as the shot-blasting time *** differences in the microhardness and tensile strength before and after shotblasting demonstrated the significant effect of the SPD layer on the mechanical *** microhardness of the homogenized HEA was~5 *** comparison,the maximum microhardness of the specimens after 20 min of shot blasting was~8.0 GPa at the *** yield strength also improved by 178%,and a large ductility of~36%was *** nanograin boundary,stacking fault,and twin strengthening within the gradientnanostructured surface layer caused the strength to *** tensile deformation,strain concentration began at the surface of the specimen and gradually spread to the ***,the gradient-nanostructured surface layer with improved strain hardening can prevent early necking and ensure steady plastic deformation so that high toughness is achieved.

关键词： High-entropy alloy Shot blasting Gradient structure Mechanical property Deformation mechanism

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Accelerating matrix/boundary precipitations to explore high-strength and high-ductile Co_(34)Cr_(32)Ni_(27)Al_(3.5)Ti_(3.5) multicomponent alloys through hot extrusion and annealing

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journal of Materials Science & Technology 2023年第12期143卷 62-83页

作者： Xiaoming Liu Zongde Kou Ruitao Qu Weidong Song Yijia Gu Changshan Zhou Qingwei Gao jiyao Zhang Chongde Cao Kaikai Song Vladislav Zadorozhnyy Zequn Zhang jürgen eckert Shenzhen Research Institute of Shandong University Shenzhen 518057China State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China School of Mechanical Electrical&Information EngineeringShandong UniversityWeihai 264209China School of Material Science and Engineering Nanjing University of Science and TechnologyNanjing 210094China School of Materials Science and Engineering Northwestern Polytechnical UniversityXi’an 710072China Department of Materials Science and Engineering Missouri University of Science and TechnologyRollaMO 65409USA Research and Development Institute of Northwestern Polytechnical University in Shenzhen Shenzhen 518057China National University of Science and Technology«MISIS» Moscow 119049Russia Erich Schmid Institute of Materials Science Austrian Academy of SciencesLeoben A-8700Austria Department of Materials Science Montanuniversität LeobenLeoben A-8700Austria

Annealing-regulated precipitation strengthening combined with cold-working is one of the most efficient strategies for resolving the conflict between strength and ductility in metals and ***,precipitation control and grain refinement are mutually contradictory due to the excellent phase stability of multicomponent *** work utilizes the high-temperature extrusion and annealing to optimize the microstructures and mechanical properties of the Co_(34)Cr_(32)Ni_(27)Al_(3.5)Ti_(3.5) multicomponent *** extrusion effectively reduces grain sizes and simultaneously accelerates the precipitation of coherent L12 nanoparticles inside the face-centered cubic(FCC)matrix and grain boundary precipitations(i.e.,submicron Cr-rich particles and L12-Ni 3(Ti,Al)precipitates),resulting in strongly reciprocal interaction between dislocation slip and hierarchical-scale *** annealing regulates grain sizes,dislocations,twins,and precipitates,further allowing to tailor mechanical *** high yield strength is attributed to the coupled precipitation strengthening effects from nanoscale coherent L12 particles inside grains and submicron grain boundary precipitates under the support of pre-existing *** excellent ductility results from the synergistic activation of dislocations,stacking faults,and twins during plastic *** present study provides a promising approach for regulat-ing microstructures,especially defects,and enhancing the mechanical properties of multicomponent alloys.

关键词： Multicomponent alloys Hot extrusion Microstructure Mechanical properties Precipitation strengthening

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New para-magnetic(CoFeNi)(50)(CrMo)(50-x)(CB)x(x=20,25,30)non-equiatomic high entropy metallic glasses with wide supercooled liquid region and excellent mechanical properties

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journal of Materials Science & Technology 2020年第8期36卷 135-143页

作者： jeong Tae Kim Sung Hwan Hong jin Man Park jürgen eckert Ki Buem Kim Erich Schmid Institute of Materials Science Austrian Academy of Sciences(ÖAW)Jahnstrae 128700LeobenAustria Hybrid Materials Center(HMC) Department of Nanotechnology and Advanced Materials EngineeringSejong University209Neungdong-roGwangjin-guSeoul143-747Republic of Korea Global Technology Center(GTC) Samsung Electronics Co.Ltd129 Samsung-roYeongtong-guSuwonsiGyeonggi-do443-742Republic of Korea Department of Materials Science Chair of Materials PhysicsMontanuniversität LeobenJahnstraße 128700LeobenAustria

In this study,high entropy metallic glasses(HEMGs)were developed through a combination of concepts for designing metallic glasses(main element+transition metal+metalloid element)and high-entropy alloys(more than five elements,each element having an atomic concentration between 5 at.%and 35 at.%).The developed metallic glass alloys are composed of Co-Fe-Ni main elements,transition metals(Cr,Mo)and metalloid elements(C,B).Moreover,the present work reports the thermal,mechanical and magnetic properties of(CoFeNi)(50)(CrMo)(50-x)(CB)x alloys with x=20,25,*** developed as-spun HEMGs exhibit typical paramagnetic properties even for a high amount of ferromagnetic elements(Co,Fe,and Ni)and have high elastic modulus(103–160 GPa)and hardness(14–27 GPa),thus possessing mechanical properties similar to well-known Co-based metallic glasses(Co-Cr-Mo-C-B system).In addition,some of the bulk samples prepared with a diameter of 2 mm form bulk metallic glasses with a high compressive strength around 3.5 *** mechanisms determining the stability of the supercooled liquid,as well as the paramagnetic and mechanical properties for the developed non-equiatomic HEMGs,are discussed.

关键词： Metallic glasses Paramagnetism High entropy alloys Phase stability

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Achieving work hardening by forming boundaries on the nanoscale in a Ti-based metallic glass matrix composite

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journal of Materials Science & Technology 2020年第15期47卷 192-203页

作者： jing Fan Wei Rao junwei Qiao PKLiaw Daniel Sopu Daniel Kiener jürgen eckert Guozheng Kang Yucheng Wu College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan030024China Key Laboratory of Interface Science and Engineering in Advanced Materials Ministry of EducationTaiyuan University of TechnologyTaiyuan030024China Key Laboratory of Advanced Technologies of Materials School of Mechanics and EngineeringSouthwest Jiaotong UniversityMinistry of Education of ChinaChengdu610031China Department of Materials Science and Engineering The University of TennesseeKnoxvilleTN37996-2200USA Technische Universitat Darmstadt Institut fiir MaterialwissenschaftFachgebiet MaterialmodellierungOtto-Bemdt-Strasse 3D-64287DarmstadtGermany Erich Schmid Institute of Materials Science Austrian Academy of SciencesJahnstra'e 12A-8700LeobenAustria Department of Materials Science Montanuniversitat LeobenJahnstra'e 12A-8700LeobenAustria

Achieving work hardening in metallic glass matrix composites(MGMCs) is the key to the extensive use of these attractive materials in structural and functional *** this study,we investigated the formation of nanoscale boundaries resulted from the interaction between matrix and dendrites,which favors the work-hardening deformation in an in-situ Ti41Zr32Ni6 Ta7 Be14 MGMC with β-Ti dendrites in a glassy matrix at room *** microstructures of samples after tension were observed by highresolution transmission electron microscopy(HRTEM) and X-ray diffraction(XRD).The work-hardening mechanism of the present composites involves:(1) appearance of dense dislocation walls(DDWs),(2)proliferation of shear bands,(3) fo rmation of boundaries on the nanoscale,and(4) interactions between hard and soft phases.A theoretical model combined with experimental data reveals the deformation mechanisms in the present work,proving that the in-situ dendrites with outstanding hardening ability in the glass matrix can provide the homogeneous deformation under tensile loading at room temperature.

关键词： Metallic glass matrix composites Plastic deformation Work hardening Dense dislocation walls Nanoscale boundaries

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Structural homology of the strength for metallic glasses

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journal of Materials Science & Technology 2021年第22期81卷 123-130页

作者： Weiming Yang Xinfa Sun Haishun Liu Changfeng Yu Wenyu Li Akihisa Inoue DanielŞopud jürgen eckert Chunguang Tang School of Mechanics and Civil Engineering State Key Laboratory for Geomechanics and Deep Underground EngineeringChina University of Mining and TechnologyXuzhou 221116China Departments of Physics College of ScienceXi’an Polytechnic UniversityXi’an 710048 China International Institute of Green Materials Josai International UniversityTogane283-8555Japan Erich Schmid Institute of Materials Science Austrian Academy of Science8700 LeobenAustria Department of Materials Science Chair of Materials PhysicsMontanuniversität Leoben8700 LeobenAustria Research School of Chemistry Energy Change InstituteAustralian National UniversityCanberra ACT 2601Australia

The structure-property relationship,one of the central themes in materials science,is far from being well understood for metallic glasses(MGs)due to the great complexity of their amorphous *** on the analysis of published experimental data for 165 MGs from more than 15 different alloy systems,the present study reveals a universal dependence of mechanical properties(Young’s moduli,shear moduli and yield strength)on simple structural parameters(the inter-atomic distance and/or valence electron density)originating from the interatomic potential and Fermi sphere-Brillouin zone *** work establishes a structure-property relationship for metallic glasses and provides insights into the fundamentals of the mechanical properties of disordered systems.

关键词： Metallic glasses Structure-property relationship Mechanical properties Inter-atomic distance Valence electron density

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Effect of Powder Particle Shape on the Properties of In Situ Ti–TiB Composite Materials Produced by Selective Laser Melting

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journal of Materials Science & Technology 2015年第10期31卷 1001-1005页

作者： Hooyar Attar Konda G.Prashanth Lai-Chang Zhang Mariana Calin Ilya V.Okulov Sergio Scudino Chao Yang jürgen eckert School of Engineering Edith Cowan University IFW Dresden Institute for Complex Materials TU Dresden Institute of Materials Science National Engineering Research Center of Near-Net-Shape Forming for Metallic Materials South China University of Technology

This work studied the preparation of starting powder mixture influenced by milling time and its effect on the particle morphology （especially the shape） and, consequently, density and compression properties of in situ Ti-TiB composite materials produced by selective laser melting （SLM） technology. Starting powder composite system was prepared by mixing 95 wt% commercially pure titanium （CP-Ti） and 5 wt% titanium diboride （TiB2） powders and subsequently milled for two different times （i.e. 2 h and 4 h）. The milled powder mixtures after 2 h and 4 h show nearly spherical and irregular shape, respectively. Subsequently, the resultant Ti-5 wt% TiB2 powder mixtures were used for SLM processing. Scanning electron microscopy image of the SLM-processed Ti-TiB composite samples show needle-shape TiB phase distributed across the Ti matrix, which is the product of an in-situ chemical reaction between Ti and TiB2 during SLM. The Ti-TiB composite samples prepared from 2 h and 4 h milled Ti-TiB2 powders show different relative densities of 99.5% and 95.1%, respectively. Also, the compression properties such as ultimate strength and compression strain for the 99.5% dense composite samples is 1421 MPa and 17.8%, respectively, which are superior to those （883 MPa and 5.5%, respectively） for the 95.1% dense sample. The results indicate that once Ti and TiB2 powders are connected firmly to each other and powder mixture of nearly spherical shape is obtained, there is no additional benefit in increasing the milling time and, instead, it has a negative effect on the density （i.e. increasing porosity level） of the Ti-TiB composite materials and their mechanical properties.

关键词： Selective laser melting In situ Ti-TiB composite Powder shape Density Mechanical properties

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