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Journal of Magnesium and Alloys 2024年第2期12卷 815-824页

作者： Tangpeng Ma Jin Wang Kaiming Cheng Chengwei Zhan Jixue Zhou jingyu qin Guochen Zhao Xinfang Zhang Shandong Provincial Key Laboratory of High Strength Lightweight Metallic Materials Advanced Materials InstituteQilu University of Technology(Shandong Academy of Sciences)Jinan 250014China Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials Ministry of EducationShandong UniversityJinan 250061China School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China

In an effort to clarify the formation mechanism of LPSO structure in Mg-Y-Zn alloy,the chemical environment and structural ordering in liquid Mg-rich Mg-Y-Zn system are investigated with the aid of ab-initio molecular dynamics *** liquid Mg-rich Mg-Y alloys,the strong Mg-Y interaction is determined,which promotes the formation of fivefold symmetric local *** Mg-Zn alloys,the weak Mg-Zn interaction results in the fivefold symmetry weakening in the liquid *** to the coexistence of Y and Zn,the strong attractive interaction is introduced in liquid Mg-Y-Zn ternary alloy,and contributes to the clustering of Mg,Y,Zn launched from *** is more,the distribution of local structures becomes closer to that in pure Mg compared with that in binary Mg-Y and Mg-Zn *** results should relate to the origins of the Y/Zn segregation zone and close-packed stacking mode in LPSO structure,which provides a new insight into the formation mechanism of LPSO structure at atomic level.

关键词： Mg-Y-Zn Chemical environment Structural ordering ab-initio molecular dynamics

The Nanoscale Density Gradient as a Structural Stabilizer for Glass Formation

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Engineering 2023年第10期29卷 120-129页

作者： Shaoxiong Zhou Bangshao Dong Yanguo Wang jingyu qin Weihua Wang China Iron and Steel Research Institute Group Beijing 100081China Institute of Advanced Materials North China Electric Power UniversityBeijing 102206China Jiangsu JITRI Advanced Energy and Materials Research Institute Changzhou 213032China Beijing National Laboratory of Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China Key Laboratory for Liquid–Solid Structural Evolution and Processing of Materials(Ministry of Education) Shandong UniversityJinan 250061China

The rapid cooling of a metallic liquid(ML)results in short-range order(SRO)among the atomic arrangements and a disordered structure in the resulting metallic glass(MG).These phenomena cause various possible features in the microscopic structure of the MG,presenting a puzzle about the nature of the MGs’microscopic structure beyond *** this study,the nanoscale density gradient(NDG)originating from a sequential arrangement of clusters with different atomic packing densities(APDs),representing the medium-range structural heterogeneity in Zr_(60)Cu_(30)Al_(10)MG,was characterized using electron tomography(ET)combined with image simulations based on structure *** coarse polyhedrons with distinct facets identified in the three-dimensional images coincide with icosahedron-like clusters and represent the spatial positions of clusters with high *** of the different clusters according to descending APD order in the glass-forming process are responsible for the NDG that stabilizes both the supercooled ML and the amorphous states and acts as a hidden rule in the transition from ML to MG.

关键词： Rapid cooling Amorphous solid Density gradient Electron tomography Atomic clusters

Investigation on structure and dynamic property of liquid Pd-Cu-Ni-P alloys using ab initio molecular dynamics simulation

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Science China(Technological Sciences) 2013年第2期56卷 376-386页

作者： qin jingyu GU TingKun PAN ShaoPeng BIAN XiuFang ZHANG Tao The Key Laboratory of Liquid Structure and Heredity of Materials Ministry of EducationShandong UniversitySouthern Campus Department of Materials Science and Engineering Beijing University of Aeronautics and Astronautics

Based on the short-range order,it is found that the abundance of the P-centered P-transition-metal clusters are the common feature among the liquid Pd-Cu-Ni-P alloys,and hence this feature alone could not uncover the underlying mechanisms of the variation of glass forming ability among the liquid *** the so called similar elements such as Cu and Ni,their behaviors are significantly different when interacting with Pd or P *** has weak bonding with both Pd and P while Ni has very strong bonding with P but nearly no bonding with *** different bonding characters thus underlie the phenomenon that in the best glass formers the ratio of the two similar elements often deviates from 1:*** if the parameters of chemical short-range order of Cu and Ni around P become closest to each other the best glass forming ability is *** is also illustrated that the calculated dynamic properties are very helpful to locate the composition of the best glass former.

关键词： liquid alloys molecular dynamics simulation short-range order self-diffusion coefficient viscosity

Atomic model of liquid pure Fe

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Chinese Science Bulletin 2001年第4期46卷 300-303页

作者： Huanrong Wang Yifu Ye Weimin Wang jingyu qin Shandong Univ Technol Coll Mat Sci & Engn Jinan 250061 Peoples R China

Using a θ-θ X-ray diffractometer, the liquid structure of pure Fe was investigated and the diffraction intensity, structure factor, pair distribution function as well as the coordination number and atomic distance were obtained. The experimental results showed that there was also a pre-peak on the curve of the structure factor of liquid pure Fe. The pre-peak is a mark of medium-range order in melts. According to the characteristics of pre-peak, an atomic model of liquid pure Fe is constructed, namely, the structure of liquid pure Fe is a combination of clusters consisting of bcc cells with shared vertexes and other atoms with random dense atom distribution.

关键词： liquid metal structure factor pre-peak X-ray diffraction.

Metastable liquid properties and rapid crystal growth of Ti-Ni-Al alloy investigated by electrostatic levitation and molecular dynamics simulation

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Science China(Technological Sciences) 2021年第10期64卷 2200-2210页

作者： XIAO RuiLin RUAN Ying LIN MaoJie qin jingyu LI Hui HU Liang WEI BingBo MOE Key Laboratory of Materials Physics and Chemistry under Extraordinary Conditions School of Physical Science and TechnologyNorthwestern Polytechnical UniversityXi’an 710072China Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials Ministry of EducationShandong UniversityJinan 250061China

Electrostatic levitation technique and molecular dynamics simulation were performed to investigate the thermophysical properties,liquid structure and crystal growth dependence on undercooling of Ti_(85)Ni_(10)Al_(5) *** liquid Ti_(85)Ni_(10)Al_(5) alloy was substantially undercooled up to 335 K(0.18T_(L)).As undercooling increased,the potential energy of the liquid alloy decreased and the alloy entered into a high metastable *** this state,the atoms tended to bond with each other and the clusters were inclined to convert into high-coordinated clusters,as confirmed by the fraction of the high-coordinated clusters *** enlarged clusters and enhanced local structure stability contributed to the increase of the thermophysical parameters and crystal growth velocity,and eventually dendrite *** density,the specific heat and the surface tension of liquid alloy exhibited a linear relation with temperature and the shear viscosity of liquid alloy showed exponential variation which showed good agreement with the calculation results by molecular dynamics *** growth velocity first increased slowly and then dramatically once the undercooling exceeded the *** achieved maximum crystal growth velocity was 12.4 m s^(−1) and it was up to 326 times of the value at 94 K undercooling.

关键词： electrostatic levitation thermophysical properties liquid structure crystal growth molecular dynamics

STRUCTURAL TRANSFORMATION AND ITS REVERSIBILITY IN LIQUID Al-13%Si ALLOY AT HIGH TEMPERATURES

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中国有色金属学会会刊：英文版 1998年第2期8卷 55-59页

作者： Wang Weimin Bian Xiufang qin jingyu Ye Yifu S.I.Sljusarenko College of Mater ials Science and Engineering Shandong University of TechnologyJi'nan 250061P.R.China Institute for Metal Physics Ukraine Academy of ScienceKievUkraine

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关键词： Al-13%Si alloy structural transformation X-ray diffraction analysis

Smart ionic liquid/water mixture system with dual stimuli-response to temperature and CO_(2)

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Nano Research 2023年第3期16卷 4152-4159页

作者： Xiaoqing Yuan Ju Liu jingyu qin Weili Ma Guangyong Liu Yanlei Wang Hongyan He Beijing Key Laboratory of Ionic Liquids Clean Process State Key Laboratory of Multiphase Complex SystemsCAS Key Laboratory of Green Process and EngineeringInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Innovation Academy for Green Manufacture Chinese Academy of SciencesBeijing 100190China

Stimuli-responsive materials have important applications in chemistry and chemical ***,we synthesized five different polyetheramine-fatty acids(PEFA)ionic liquids(ILs),possessing the dual stimuli-responsive ability to temperature and CO_(2).These PEFA ILs have reversible lower critical solution temperature(LCST)phase behavior over a wide temperature range of 37-91℃,and reversible heterogeneous-homogeneous phase transition towards the addition and removal of CO_(2).Furthermore,the droplet size of the IL-water mixture system increased from 6.5 to 21.0 nm as the temperature increased from 25 to 56℃,and then recovered to 6.5 nm when the temperature decreased to 25℃.The addition and removal of CO_(2)also reversibly modulated the droplet size of the *** from nuclear magnetic resonance(NMR)and Fourier transform infrared(FTIR)spectra further showed that the temperature-dependent conformation of polyether amine chain in the cation dominates the temperature response,while the reversible formation of bicarbonate and fatty acids(FA)from CO_(2)and anion controls the CO_(2)-based reversible phase *** simulations revealed a microscopic response mechanism of the IL-water system to temperature and CO_(2),and a synergistic effect between the dual stimuli of temperature and CO_(2).These findings may provide a basis for the rational design and understanding of ILs-based stimuli-responsive materials and nanoreactors.

关键词： stimuli-responsive ionic liquids phase transitions temperature CO_(2)

Pre-peak on the structure factor of liquid hypoeutectic Al-Fe alloy

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Chinese Science Bulletin 1998年第14期43卷 1219-1224页

作者： jingyu qin Xiufang Bian Weimin Wang Jiaji Ma Changye Xu Shandong Univ Technol Coll Mat Sci & Engn Jinan 250061 Peoples R China Shandong Univ Technol Dept Math & Phys Jinan 250061 Peoples R China

Using a θ-θ X ray diffractometer the structure of liquid hypoeutectic Al Fe alloy at 675℃ and its change with different thermal histories are investigated . Liquid Al is used as a reference system. It is found that a pre peak appears on the small angle part of the structure factor of the nonsuperheated hypoeutectic Al Fe alloy, but disappears after superheating whereas the structure factors of liquid Al hardly change with the different thermal histories, and no pre peak can be observed on them. The appearance of a pre peak is a mark of the intermediate range order (IRO). The pre peak is taken as the correlation between Fe atoms on the IRO length scale. Assume that the crystalline structure is the first order approximation of the liquid structure. A model structure is constructed. The basic unit is a cube formed by 8 Al atoms on its corner and one Fe atom occupying its center. The translation of such a unit along its fourbody diagonals by the length of a diagonal can meet the requirement of the Fe_Fe distance and gives a DO 3 like structure. If the vacancy among the units is filled with fcc like Al cells, the composition of the entity is about Al 7Fe, close to that of the metastable phase Al 6Fe from rapid solidification. It is speculated that there are Al 6Fe like clusters in the liquid hypoeutectic Al Fe alloy.

关键词： liquid hypoeutectic Al Fe alloy structure factor pre peak X ray diffraction.

The hidden disintegration of cluster heterogeneity in Fe-based glass-forming alloy melt

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Progress in Natural Science:Materials International 2018年第6期28卷 696-703页

作者： Bangshao Dong Shaoxiong Zhou jingyu qin Ying Li Hui Chen Yanguo Wang Advanced Technology & Materials Co. Ltd. Central Iron & Steel Research Institute Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education) Shandong University Nanjing Tengyuan Soft Magnetics Co.Ltd.

The evolution of liquid metal at high temperature is known much less than their solid states. This is partially due to that the message concerning clusters, metastable phase or heterogeneity in liquid is usually too slight to be traced. Here, we shed some light on the nature of structural evolution of Fe-based glass-forming alloy during overheating process by the investigation of high-temperature melt viscometry and first principles simulations. It was found that a structural transition around 1400 ℃ occurred in the melts of initial homogeneous ingot, heterogeneous ingot and amorphous ribbons jointly, and was confirmed by the results from differential scanning calorimeter(DSC), and ab initio molecular dynamics(AIMD). Combining these results with Fe-Si-B ternary phase diagram and the melting characteristics of Fe-B compounds, it is safe to conclude that the disintegration of Fe2B type clusters to Fe3B-type clusters leads to the observed transition. These results offer a significant reference for the preparation and property control of Fe-based amorphous alloys.

关键词： Fe-based glass-forming alloys Alloy melt Cluster heterogeneity Structural transition Viscosity

Influence of clusters in melt on the subsequent glass-formation and crystallization of Fe–Si–B metallic glasses

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Progress in Natural Science:Materials International 2015年第2期25卷 137-140页

作者： Shaoxiong Zhou Bangshao Dong Rui Xiang Guangqiang Zhang jingyu qin Xiufang Bian Advanced Technology & Materials Co. Ltd. Central Iron & Steel Research Institute Key Laboratory for Liquid–Solid Structural Evolution and Processing of Materials (Ministry of Education) Shandong University

The liquid structure of seven representative Fe–Si–B alloys has been investigated by ab initio molecular dynamics simulation focusing on the role of clusters in terms of glass-forming ability(GFA) and crystallization. It is demonstrated that the type of primary phase precipitated from amorphous state under heat treatment is determined by the relative fraction and role of various clusters in melt. The alloy melt shows higher stability and resultantly larger GFA when there is no dominant cluster or several clusters coexist, which explains the different GFAs and crystallization processes at various ratios of Si and B in the Fe–Si–B system. The close correlation among clusters, crystalline phase and GFA is also studied.

关键词： Metallic glasses Clusters Glass-forming ability Primary phase ab initio molecular dynamics