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single crystal of Lanthanum Hydroxide La（OH）3： Controlled Synthesis by High Pressure Flux Method and Its Growth Mechanism

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Chemical Research in Chinese Universities 2013年第5期29卷 825-827页

作者： LI Ben-xian LIU Xiao-yang CHU Qing-xin LI Guang-hua WANG Xiao-feng ZHAO Xu-dong State Key Laboratory of lnorganic Synthesis and Preparative Chemistry College of Chemistry Jilin University Changehun 130012 P. R. China College of Earth Science Jilin University Changehun 130061 P R. China

High pressure synthesis of solid material tends to increase the density, coordination number, symmetry of material and shorten bond length. The solid synthesized at a high pressure and decompressed to ambient pressure often exhibits a meta- stable ＂stretched＂ state, within the high pressure stability field. The crystal grown at a high pressure is of great importance with the development of high pressure technology. crystal growth is an important factor in the material synthesis. And many me- thods including gas, solid and solution methods have been used to obtain various single crystalstl]. Especially, flux method is an important method for crystal growth, where the components of the desired substance dissolved in a solvent（flux） grow in the process of deposit.

关键词： Lanthanum hydroxide High pressure Flux method single crystal

single crystal growth and electrochemical studies of garnet-type fast Li-ion conductors

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Tungsten 2022年第4期4卷 263-268页

作者： Yi-Tian Wang Xi Chen Department of Electrical and Computer Engineering University of CaliforniaRiversideCA92521USA

All-solid-state batteries have attracted much attention due to their improved safety and higher energy density as compared to the conventional *** to the excellent chemical stability against lithium metal and relatively high ionic conductivity at room-temperature,garnet-type fast lithium ion conductors with three-dimensional lithium ion transport channels are promising solid electrolytes for all-solid-state *** order to better understand the intrinsic lithium-ion transport mechanisms and prevent lithium dendrite formation,it is desired to investigate single-crystal solid *** this perspective,we review several methods reported to grow single crystals of garnet-type *** and cons of different growth methods are ***,we introduce some case studies on electrochemical properties of garnet-type single *** addition,we provide some perspectives about potential research directions of single-crystal solid electrolytes for all-solid-state batteries.

关键词： Solid electrolyte single crystal Garnet-type lithium-ion conductor All-solid-state battery crystal growth

A self-power photodetector based on controlled growth of single crystal MAPbBr_(3)/WO_(3) heterojunction

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Science China(Technological Sciences) 2023年第9期66卷 2660-2668页

作者： YAO JianFeng ZHANG Hu LU JunZheng YANG LiangPan LIU DuanWangDe HU YaLi ZENG Wei GUI PengBin CHEN ZhiLiang REN XinGang Information Materials and Intelligent Sensing Laboratory of Anhui Province Anhui UniversityHefei 230039China Anhui Province Key Laboratory of Target Recognition and Feature Extraction Lu’an 237009China Hefei Comprehensive National Science Center Hefei 230601China School of Physics and Electronic Engineering Hubei University of Arts and ScienceXiangyang 441053China

Compared with polycrystalline films, perovskite single crystal is considered as a promising photoelectric material due to its unique advantages in quantum efficiency and carrier diffusion length. In this work, the micron-thickness MAPbBr_(3) single crystal was prepared through a highly repeatable process based on the crystal seed dissolution-growth method. A heterojunction of MAPbBr_(3)/WO_(3) single crystal was realized through a simple thermal evaporation process, and the integrated C/MAPbBr_(3)/WO_(3)/C device demonstrated self-powered characteristics and high photoelectric performance, which showed good responsivity of about 111 mA/W, detectivity of 9.64×10^(11) Jones and fast response speed(0.11/0.56 ms). Meanwhile, the device exhibited good rectification performance(ratio of 125 at ±2 V) and reduced dark current due to the built-in electric field formed in the heterojunction. This study provides a facile, flexible, and highly repeatable method for the preparation of high-performance photodetectors based on MAPbBr_(3) single crystals with micrometer thickness.

关键词： perovskite single crystal heterojunction self-powered photodetectors

Prediction of Primary Dendrite Arm Spacing in Pulsed Laser Surface Melted single crystal Superalloy

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Acta Metallurgica Sinica(English Letters) 2021年第4期34卷 485-494页

作者： Shiwei Ci Jingjing Liang Jinguo Li Haiwei Wang Yizhou Zhou Xiaofeng Sun Hongwei Zhang Yutian Ding Xin Zhou Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang110016China Space Manufacturing Technology(CAS Key Lab) Beijing100094China Taizhou Xinma Technology Industry Develepment Co.Ltd Taizhou318000China State Key Laboratory of Advanced Processing and Recycling of Non-Ferrous Metal Lanzhou University of Technology287 Langongping RoadLanzhou730000China Science and Technology On Plasma Dynamics Laboratory Air Force Engineering UniversityXi’an710000China

Primary dendritic arm spacing(PDAS)is an important microstructure feature of the nickel-base single crystal *** this paper,a numerical model predicting the PDAS evolution with additive manufacturing parameters using pulsed laser is established,which combines the theoretical PDAS models with the temperature field calculation model during pulsed laser *** on this model,processing maps that related process parameters to the evolution of PDAS are *** obtain more accurate prediction model,the parameters of different solidification conditions,G^(-0.5)V^(-0.25) and G^(-0.5)V^(-0.25),are selected to calculate *** simulation results show that the PDAS increases as the arise of P and *** processmgPDAS map can accurately predict the evolution of PDAS with pulsed laser process parameters,which is well in accordance with the experimental ***,the PDAS values calculated by the G^(-0.5)V^(-0.25) are more in line with the experimental results than those calculated by the G^(-0.5)V^(-0.25).

关键词： Additive manufacturing Nickel-base superalloy single crystal Pulsed laser Primary dendritic arm spacing

A Comparative Investigation of single crystal and Polycrystalline Ni-Rich NCMs as Cathodes for Lithium-Ion Batteries

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Energy & Environmental Materials 2023年第3期6卷 1-7页

作者： Xianming Deng Rui Zhang Kai Zhou Ziyao Gao Wei He Lihan Zhang Cuiping Han Feiyu Kang Baohua Li Shenzhen Key Laboratory of Power Battery Safety and Shenzhen Geim Graphene Center Tsinghua Shenzhen International Graduate SchoolTsinghua UniversityShenzhen 518055China School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China EVE Energy Co. Ltd.No.38Hui Feng 7th RoadZhongkai Hi-Tech ZoneHuiZhou Guangdong 516006China Shenzhen Key Laboratory of Energy Materials for Carbon Neutrality and Faculty of Materials Science and Engineering Shenzhen Institutes of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China

Nickel-rich LiNi_(1-x-y)Co_(x)Mn_(y)O_(2)(NCM,1-x-y≥0.6)is known as a promising cathode material for lithium-ion batteries since its superiority of high voltage and large ***,polycrystalline Ni-rich NCMs suffer from poor cycle stability,limiting its further ***,single crystal and polycrystalline LiNi_(0.84)Co_(0.07)Mn_(0.09)O_(2)cathode materials are compared to figure out the relation of the morphology and the electrochemical storage *** to the Li^(+)diffusion coefficient,the lower capacity of single crystal samples is mainly ascribed to the limited Li+diffusion in the large *** situ XRD illustrates that the polycrystalline and single crystal NCMs show a virtually identical manner and magnitude in lattice contraction and expansion during ***,the electrochemically active surface area(ECSA)measurement is employed in lithium-ion battery study for the first time,and these two cathodes show huge discrepancy in the ECSA after the initial *** results suggest that the single crystal sample exhibits reduced cracking,surface side reaction,and Ni/Li mixing but suffers the lower Li^(+)diffusion *** work offers a view of how the morphology of Ni-rich NCM effects the electrochemical performance,which is instructive for developing a promising strategy to achieve good rate performance and excellent cycling stability.

关键词： cathodes electrochemically active surface area Li^(+)diffusion coefficient lithium-ion batteries single crystal

Effect of solidification rate on MC-type carbide morphology in single crystal Ni-base superalloy AM3

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Transactions of Nonferrous Metals Society of China 2010年第10期20卷 1835-1840页

作者：余竹焕刘林赵新宝张卫国张军傅恒志 State Key Laboratory of Solidification Processing Northwestern Polytechnical University Material Science and Engineering Department Xi'an Un iversity of Science and Technology

In order to study the effect of the withdrawing rate on carbide morphology,MC-type carbide in single crystal superalloy AM3 was systematically investigated with sample growth rates from 3.5 μm/s to 500 μm/*** carbide morphologies were investigated by scanning electron microscopy(SEM),and the electron probe microanalysis(EPMA) was used to characterize the carbide *** results indicate that the solidification rate is the important factor governing MC carbide growth morphology,size and distribution,composition and growth *** the increase of withdrawing rate,nodular,rod-like,Chinese script types of carbide morphology are *** the low withdrawing rate,with the increase of withdrawing rate,the carbide size becomes *** the case of dendritic interface,the carbide size becomes smaller with refinement of dendrites as withdrawing rate *** volume fraction of carbides increases with the withdrawing rate increasing.

关键词： single crystal Ni-base superalloy carbide morphology withdrawing rate

Improved mechanical properties of Ni-rich Ni3Al coatings produced by EB-PVD for repairing single crystal blades

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Rare Metals 2017年第7期36卷 556-561页

作者： Jing-Yong Sun Yan-Ling Pei Shu-Suo Li Hu Zhang Sheng-Kai Gong School of Materials Science and Engineering Beihang UniversityBeijing 100191China

Active control of turbine blade tip clearance for aircraft engine continues to be a concern in engine opera- tion, because turbine blades are subjected to wear and therefore cause an increasing tip clearance between the rotating blades and the shroud and also reduce the engine efficiency. In this work, a Ni-rich Ni3A1 coating with γ＇/γ two-phase microstructure was deposited by electron beam physical vapor deposition （EB-PVD）, which worked as repairing the worn blade tips of single crystal blades. Nb molten pool was used to increase the molten pool tem- perature and thus to enhance the deposition rate. The microstructures and mechanical properties can be modified by the deposition temperatures and the following heat treatments. All coatings consist of γ＇ and γ phases. At deposition temperature of 600 ℃, a dense microstructure can be achieved to produce a coating with grain size of 1 μm and microhardness of -HV 477. After being heated for 4 h at a temperature of 1,100 ℃, the coatings have a more uniform microstructure, and microhardness maintains at a high level of -HV 292. Effect of Hf and Zr on EB-PVD Ni3Al repair coating will be further investigated.

关键词： Repair coating Ni3A1 Electron beamphysical vapor deposition Blades tips single crystal Heat treatment

Numerical Simulation of Solidification Process on single crystal Ni-Based Superalloy Investment Castings

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Journal of Materials Science & Technology 2007年第1期23卷 47-54页

作者： Jing YU Qingyan XU Kai CUI Baicheng LIU Akihiko KIMATSUKA Key Laboratory for Advanced Materials Processing Technology Ministry of Education Department of Mechanical Engineering Tsinghua University Beijing 100084 China Ishikawajima-Harima Heavy Industries Co. Ltd. Isogo-Ku Yokohama 235-8501 Japan

Bridgman directional solidification of investment castings is a key technology for the production of reliable and highly efficient gas turbine blades. In this paper, a mathematical model for three-dimensional （3D） simulation of solidification process of single crystal investment castings was developed based on basic heat transfer equations. Complex heat radiation among the multiple blade castings and the furnace wall was considered in the model. Temperature distribution and temperature gradient in superalloy investment castings of single blade and multiple ones were investigated, respectively. The calculated cooling curves were compared with the experimental results and agreed well with the latter. It is indicated that the unsymmetrical temperature distribution and curved liquid-solid interface caused by the circle distribution of multiple turbine blades are probably main reasons why the stray grain and other casting defects occur in the turbine blade.

关键词： Directional solidification single crystal Investment casting Numerical simulation

Increasing high-temperature fatigue resistance of polysynthetic twinned TiAl single crystal by plastic strain delocalization

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Journal of Materials Science & Technology 2021年第34期93卷 53-59页

作者： Yang Chen Yuede Cao Zhixiang Qi Guang Chen MIT Key Laboratory of Advanced Metallic and Itermetalic Materials Techmology Engineering Research Center of Materials Behavior and Design Ministry of EducotionNanjing University of Science and TechnologyNanjing 210094Chind

Polysynthetic twinned(PST)TiAl single crystal possesses great potentials for high-temperature applications due to its excellent combination of strength,ductility and creep ***,a critical property for high-temperature application of such material involving high-temperature fatigue properties remains ***,the high-temperature high-cycle fatigue performance of PST TiAl single crystal has been *** result shows that PST TiAl single crystal can withstand more than 107 cyclic loadings at 975℃ under a stress amplitude of 270 MPa,which is significantly higher than traditional TiAl *** observations and atomistic simulations indicate that the improvement of fatigue resistance is attributed to the plastic strain delocalization in uniform lamellar structure,and the plastic deformation is well-distributed and sufficient in each *** in theα2 lamella with difficult slippage,a large number of stacking fault structures can be ***{c+a}dislocations inα2 tend to dissociate into a Frank partial with b=1/6,forming a ribbon of I1 fault which ensures the continuity of deformation.

关键词： TiAl single crystal Fatigue High temperature Strain delocalization