检索结果-南通市图书馆

Journal of Materials Science & Technology 2023年第7期138卷 117-128页

作者： Zhifeng Huang jian-feng nie Department of Materials Science and Engineering Monash UniversityMelbourneVIC 3800Australia

Interactions of solute atoms in biodegradable zinc alloys and their effect on alloy mechanical properties have been less *** this work,the interactions between the common solutes(Li,Mg,Mn,Cu,and Ag)used in the biodegradable Zn alloys,including a solute-solute pair with the same element or with two different elements,are investigated based on first-principles *** is found that the energetically favorable configuration is the third nearest-neighboring for most solute-solute pairs in the bulk lattice because of the relatively strong electronic interaction between solute and Zn atoms or the relatively small local elastic deformation associated with the *** that interfacial cleavage is a key fracture mode of zinc,the segregation ability of these solutes and their effect on the{1012}twin boundary cohesion are also *** result shows that Li tends to fully occupy its preferred site in the twin boundary,while Mg,Mn,Cu,or Ag has a concentration limitation in the twin *** twin boundary cohesion can be significantly enhanced by the segregation of Mn,followed by Cu and Ag,because of the contribution of their d states close to the Fermi ***,the co-segregation ability of two solute atoms in the twin boundary increases with increasing the binding tendency of these two solute atoms in the *** and Li or Mg show a relatively strong co-segregation ability in the twin *** Mn to Zn-Li or Zn-Mg alloys can significantly enhance the resistance to fracture of twin boundaries.

关键词： Zinc alloys Twin boundary Solute-solute interaction Co-segregation Interfacial fracture

Twin-solute, twin-dislocation and twin-twin interactions in magnesium

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2023年第10期11卷 3427-3462页

作者： Yuan Yue jian Wang jian-feng nie Department of Materials Science and Engineering Monash UniversityVictoria 3800Australia Department of Mechanical&Materials Engineering University of Nebraska-LincolnLincolnNE 68583USA

Magnesium alloys have received considerable research interest due to their lightweight,high specific strength and excellent ***,their plastic deformation is more complicated compared to cubic materials,primarily because their low-symmetry hexagonal closepacked(hcp) crystal *** twinning is a crucial plastic deformation mechanism in magnesium,and twins can affect the evolution of microstructure by interacting with other lattice defects,thereby affecting the mechanical *** paper provides a review of the interactions between deformation twins and lattice defects,such as solute atoms,dislocations and twins,in magnesium and its *** review starts with interactions between twin boundaries and substitutional solutes like yttrium,zinc,silver,as well as interstitial solutes like hydrogen and *** is followed by twin-dislocation interactions,which mainly involve those between {10■2} tension or {10■1} compression twins and , or type *** following section examines twin-twin interactions,which occur either among the six variants of the same {10■2} or {10■1} twin,or between different types of *** resulting structures,including twin-twin junctions or boundaries,tension-tension double twin,and compression-tension double twin,are discussed in ***,this review highlights the remaining research issues concerning the interactions between twins and lattice defects in magnesium,and provides suggestions for future work in this area.

关键词： Magnesium alloys Twin-solute interactions Twin-dislocation interactions Twin-twin interactions Microstructure Mechanical properties

Electron beam irradiation induced metastable phase in a Mg-9.8 wt%Sn alloy

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第25期84卷 133-138页

作者： Chaoqiang Liu Houwen Chen Min Song jian-feng nie State Key Laboratory of Powder Metallurgy Central South UniversityChangsha410083China College of Materials Science and Engineering Chongqing UniversityChongqing400044China Electron Microscopy Center Chongqing UniversityChongqing400044China Department of Materials Science and Engineering Monash UniversityVictoria3800Australia

Aberration-corrected scanning transmission electron microscopy has been used to study a novel metastable phase,designated asβ’’phase,induced to form by electron beam irradiation in a Mg-9.8 wt.%Sn *** phase is spherical in three dimensions,having a D019 structure with the lattice parameters of a=0.642 nm,c=0.521 nm and space group of P63/*** chemical formula is Mg_(3)Sn,like theβ’metastable precipitate *** orientation relationship between theβ’’phase and theα-Mg matrix is such that■_(β)’’//■_(α)and(0001)_(β)’’//(0001)_(α).Its formation involves solely the ordering of Sn atoms in the solid solution magnesium ***-principles calculations indicate that the formation of theβ’’phase is energetically favored.

关键词： Mg-Sn alloys Metastable phase Irradiation HAADF-STEM Density functional theory

Heat-treatable Mg-9Al-6Sn-3Zn extrusion alloy

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2018年第2期34卷 284-290页

作者： Chaoqiang Liu Chenglong Liu Houwen Chen jian-feng nie College of Materials Science and Engineering Chongqing University Electron Microscopy Center of Chongqing University Chongqing University Department of Materials Science and Engineering Monash University

Mg-9Al-6Sn-3Zn （wt%） alloy was extruded and heat treated in T5 and T6 conditions, and its mechanical properties and microstructures were investigated. The extruded product can be slightly strengthened by the T5 treatment as a result of sparse and heterogeneous precipitation. Significant increase in strength is achieved by the T6 treatment, and this is mostly attributed to the formation of lamellar discontinuous Mg17Al12 precipitates. The segregation of Al and Zn at grain boundaries is responsible for the discontinuous Mg17Al12 nucleation. The T6-treated alloy exhibits a tensile yield strength of 341 MPa and an ultimate tensile strength of 409 MPa, together with an elongation to fracture of 4%.

关键词： Magnesium alloys Extrusion Mechanical property Precipitation Electron microscopy

Symmetric or asymmetric glide resistance to twinning disconnection?

在线全文

学校读者我要写书评

暂无评论

npj Computational Materials 2022年第1期8卷 1615-1621页

作者： Mingyu Gong Houyu Ma Kunming Yang Yue Liu jian-feng nie jian Wang State Key Lab of Metal Matrix Composites School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai200240P.R.China Department of Materials Science and Engineering Monash UniversityClaytonVIC3800Australia Department of Mechanical&Materials Engineering University of Nebraska-LincolnLincolnNE68583USA

Successive gliding of twinning disconnections(TDs)creates three-dimensional twins in parent crystal and accommodates shear *** is generally recognized that TD is subject to the same Peierls stress as it glides forward or backward because of its dislocation character and the twofold rotation symmetry of the twin *** on atomistic simulations,we demonstrate that the glide of TDs may be subject to a symmetric or asymmetric resistance corresponding to step character,symmetric resistance for A/A type steps but asymmetric resistance for A/B type steps,where A and B represent crystallographic planes in twin and ***,we experimentally demonstrate that the asymmetric resistance results in asymmetric propagation and growth of twins in Mg alloys.

关键词： resistance deformation. steps

Ordered Sn distribution adjacent to the precipitate-matrix interface in a Mg-9.8wt.%Sn alloy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2022年第7期10卷 1909-1914页

作者： Chaoqiang Liu Houwen Chen Min Song jian-feng nie State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China International Joint Laboratory for Light Alloys(MOE) College of Materials Science and EngineeringChongqing UniversityChongqing 400044China Department of Materials Science and Engineering Monash UniversityVictoria 3800Australia

The major interface betweenβ-Mg_(3)Sn precipitate plate and theα-Mg matrix in a Mg-9.8wt.%alloy has been investigated using aberrationcorrected scanning transmission electron microscopy and first-principles *** is found that Sn atoms orderly distribute in the single layer of theα-Mg matrix immediately adjacent to the broad surface ofβat the early stage of *** Sn atoms substitute Mg atoms located at the centers of equilateral triangles constituted by three Mg columns in the outmost layer ofβ.First-principles calculations suggest that the ordered Sn distribution is energetically favored and it not only decreases the interfacial energy of theβ-matrix interface but also hinders the occurrence of 1/3αshear that thickens theβplate.

关键词： Mg-Sn alloys Ordered distribution of solute atom HAADF-STEM First-principles calculations

Nucleation of recrystallization in magnesium alloy grains of varied orientation and the impacts on texture evolution

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2022年第11期10卷 3041-3053页

作者： Victoria M.Miller jian-feng nie Tresa M.Pollock Department of Materials Science and Engineering University of FloridaGainesvilleFL 32611USA Department of Materials Science and Engineering Monash UniversityVictoria 3800Australia Materials Department University of California Santa BarbaraSanta BarbaraCA 93106-5050USA

Selection of appropriate thermomechanical processing parameters is crucial for control of the crystallographic texture and grain size distribution in wrought magnesium alloys, which in turn dictate their mechanical properties. In this work, the recrystallization behavior of binary Mg-Zn alloys are examined after warm rolling as a function of alloy content and heat treatment temperature. The Avrami exponent increased with increasing heat treatment temperature up to the Mg Zn solvus, while the strength of the recrystallization texture *** the Avrami exponent nor the qualitative trends in texture evolution were sensitive to the Zn alloying content in the examined *** and transmission electron microscopy observations revealed that the changes in texture and recrystallization kinetics could be attributed to differences in the nucleation behavior of basal and off-basal orientations.

关键词： Magnesium alloys Recrystallization Dislocation substructure Texture

Solute atom segregation to I1 stacking fault and its bounding partial dislocations in a Mg–Bi alloy

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2024年第8期12卷 3135-3141页

作者： Cong He Yong Zhang Zhiqiao Li Houwen Chen jian-feng nie International Joint Laboratory for Light Alloys(Ministry of Education) College of Materials Science and EngineeringChongqing UniversityChongqing 400044PR China Research Center for Magnetic and Spintronic Materials National Institute for Materials ScienceTsukuba 305-0047Japan Department of Materials Science and Engineering Monash UniversityVictoria 3800Australia State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Hunan UniversityChangsha 410082PR China

Stacking faults(SFs)and the interaction between solute atoms and SFs in a Mg–Bi alloy are investigated using aberration-corrected scanning transmission electron *** is found that abundant I_(1)SFs are generated after cold rolling and are mainly distributed inside{1012}*** aging treatment,the formation of single-layer and three-layer Bi atom segregation in the vicinity of I_(1)fault are clearly *** segregation also occurs at the 1/6bounding Frank partial dislocation *** segregation behaviors in I_(1)fault and Frank dislocations are discussed and rationalized using first-principles calculations.

关键词： Mg alloys Suzuki segregation Stacking fault Frank partial dislocation

Atomic-scale investigation of precipitate phases in QE22 Mg alloy

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2024年第10期177卷 114-127页

作者： Xiaojun Zhao Zhiqiao Li Aiping Zhang Longlong Hao Houwen Chen jian-feng nie Key Laboratory of Advanced Technologies of Materials Ministry of EducationSouthwest Jiaotong UniversityChengdu 610031China International Joint Laboratory for Light Alloys(MOE) College of Materials Science and EngineeringChongqing UniversityChongqing 400044China Department of Materials Science and Engineering Monash UniversityVictoria 3800Australia

Precipitation-hardenable commercial Mg alloy QE22(***-0.7Zr,wt.%)has excellent mechan-ical properties,but precipitates in this alloy have not been well *** this work,precipitate phasesγ",γ,andδformed during the isothermal ageing process at 150,200,250,and 300℃have been characterized using atomic-resolution high-angle annular dark-field scanning transmission electron mi-croscopy and atomic-scale energy-dispersive X-ray *** morphology,crystal structure,and orientation relationship of these precipitate phases have been *** boundaries usually exist in a singleγparticle,which can be characterized by a separation vector of[1(1)01]_(α).Theδphase forms in situ from its precursorγphase,consequently leading to the formation of three different variants within a single 8 *** nucleation of theδphase is strongly related to the domain boundaries of the y *** formation of theγphase may be promoted by its precursorγ"*** similarities in atomic structures of theγ",γ,andδphases are described and discussed,indicating that transfor-mations between these precipitate phases can be accomplished through the diffusion of added alloying elements.

关键词： Magnesium alloy Precipitation Phase identification Phase transformation Electron microscopy

Investigating the stress corrosion cracking of a biodegradable Zn-0.8 wt%Li alloy in simulated body fluid

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Bioactive Materials 2021年第5期6卷 1468-1478页

作者： Guan-Nan Li Su-Ming Zhu jian-feng nie Yufeng Zheng Zhili Sun Department of Materials Science and Engineering College of EngineeringPeking UniversityBeijing100871China Department of Materials Science and Engineering Monash UniversityClaytonAustralia International Research Organization for Advanced Science and Technology Kumamoto University2-39-1 KurokamiChuo-KuKumamoto860-8555Japan State Key Laboratory for Turbulence and Complex System College of EngineeringPeking UniversityBeijing100871China

Stress corrosion cracking(SCC)may lead to brittle,unexpected failure of medical ***,available researches are limited to Mg-based biodegradable metals(BM)and pure *** stress corrosion behaviors of newly-developed Zn alloys remain *** the present work,we conducted slow strain rate testing(SSRT)and constant-load immersion test on a promising Zn-0.8 wt%Li alloy in order to investigate its SCC susceptibility and examine its feasibility as BM with pure Zn as control *** observed that Zn-0.8 wt%Li alloy exhibited low SCC *** was attributed to variations in microstructure and deformation mechanism after alloying with *** addition,both pure Zn and Zn-0.8 wt%Li alloy did not fracture over a period of 28 days during constant-load immersion *** magnitude of applied stress was close to physiological condition and thus,we proved the feasibility of both materials as BM.

关键词： Biodegradable metals Zn-0.8 wt%Li alloy Stress corrosion Slow strain rate testing Constant-load immersion test