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Investigation into Deformation of three-dimensional microstructures via Surface Tension of a Rinsing Material During a Developing Process

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TRANSACTIONS OF THE KOREAN SOCIETY OF MECHANICAL ENGINEERS A 2008年第4期32卷 303-309页

作者： Park, Sang-Hu Yang, Dong-Yol

Dense and fine polymer patterns often collapse, as they come into contact with each other at their protruding tips. Resist pattern collapse depends on the aspect ratio of patterns and the surface tension of rinsing materials. The pattern collapse is a very serious problem in microfabrication, because it is one of the factors which limit the device dimensions. The reasons for the pattern collapse are known as the surface tension of rinse liquid, centrifugal force and rinse liquid flow produced in the developing process. In this work, we tried to evaluate the pattern collapse of three-dimensional microstructures that were fabricated by two-photon induced photopolymerization, and showed the way how to reduce the deformation of microstructures.

关键词： Two-Photon Polymerization 3D Pattern Collapse three-dimensional microstructure Surface Tension

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Effect of Solidification Condition and Carbon Content on the Morphology of MC Carbide in Directionally Solidified Nickel-base Superalloys

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Journal of Materials Science & Technology 2014年第12期30卷 1296-1300页

作者： X.W.Li L.Wang J.S.Dong L.H.Lou Superalloys Division Institute of Metal Research Chinese Academy of Sciences

Evolution of the morphology of MC carbides with the change of cooling rate and carbon content in two kinds of nickel-base superalloys, K417 G and DD33, has been investigated. The morphology of MC carbides evolves from faceted to script-like with increasing cooling rate. Varying the carbon content from 40X10-6 to 320X10-6, the morphology of carbides changes from blocky, rod-like into script-like. Scanning electron microscopy observation of deep-etched samples indicates that these carbides evolve from octahedral to dendritic and then into welldeveloped dendrites accordingly in a three-dimensional manner. The morphology evolution is discussed from the viewpoint of the preferential growth orientation of fcc crystals and the carbide growth rate during directional solidification.

关键词： Carbides morphology Directional solidification three-dimensional microstructure Nickel-base superalloys

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Deriving grain boundary character distributions and relative grain boundary energies from three-dimensional EBSD data

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MATERIALS SCIENCE AND TECHNOLOGY 2010年第6期26卷 661-669页

作者： Rohrer, G. S. Li, J. Lee, S. Rollett, A. D. Groeber, M. Uchic, M. D. Carnegie Mellon Univ Dept Mat Sci & Engn Pittsburgh PA 15213 USA USAF Res Lab Mat & Mfg Directorate MLLMD Wright Patterson AFB OH 45433 USA

three-dimensional electron backscatter diffraction data, obtained by serial sectioning a nickel base superalloy, has been analysed to measure the geometric arrangement of grain boundary planes at triple junctions. This information has been used to calculate the grain boundary character distribution (GBCD) and the grain boundary energy distribution (GBED). The twin content from the three-dimensional GBCD calculation compares favourably with the twin content estimated by stereology. Important factors in the analysis are the alignment of the parallel layers, the ratio of the out-of-plane to in-plane spacing of the discrete orientation data and the discretisation of the domain of grain boundary types. The results show that grain boundaries comprised of (111) planes occur most frequently and that these grain boundaries have a relatively low energy. The GBCD and GBED are inversely correlated.

关键词： Grain boundaries Grain boundary energy Superalloy EBSD Serial sectioning three-dimensional microstructure

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Reconstruction and visualization of complex 3D pore morphologies in a high-pressure die-cast magnesium alloy

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MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES microstructure AND PROCESSING 2006年第1-2期427卷 92-98页

作者： Lee, S. G. Gokhale, A. M. Sreeranganathan, A. Georgia Inst Technol Sch Mat Sci & Engn Atlanta GA 30332 USA

Visualization and representation of three-dimensional (313) pore morphologies in the high-pressure die-cast Mg alloys are of significant interest for understanding and modeling processing-microstructure-properties relationships. In this contribution, an efficient and unbiased montage serial sectioning technique is applied for reconstruction of large volume (similar to 1.24 x 10(9) mu m(3)) high-resolution (similar to 1 mu m) 3D microstructure of a high-pressure die-cast AM50 Mg alloy containing gas (air) and shrinkage pores. The reconstruction of 3D microstructure from montage serial sections enables visualization and characterization of detailed 3D morphologies and spatial correlations of gas (air) and shrinkage pores. The reconstructed 3D microstructure is implemented in a 3D finite elements (FE) computational framework to illustrate how realistic complex microstructural feature morphologies can be incorporated in the simulations of micromechanical response of these high-pressure die-cast cast microstructures. (c) 2006 Elsevier B.V. All rights reserved.

关键词： AM50 magnesium alloys porosity three-dimensional microstructure finite elements based simulations

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Fabrication of three-dimensional Flower-like Heterogeneous Fe3O4/Fe Particles with Tunable Chemical Composition and Microwave Absorption Performance

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ACS APPLIED MATERIALS & INTERFACES 2019年第21期11卷 19267-19276页

作者： Li, Xueai Qu, Xiangyan Xu, Zhan Dong, Wenqi Wang, Fengyan Guo, Wanchun Wang, Haiyan Du, Yunchen Yanshan Univ Coll Environm & Chem Engn Qinhuangdao 066004 Hebei Peoples R China Harbin Inst Technol Sch Chem & Chem Engn MIIT Key Lab Crit Mat Technol New Energy Convers Harbin 150001 Heilongjiang Peoples R China

Heterogeneous Fe3O4 and Fe composites are highly desirable for microwave absorption application because of their complementary electromagnetic (EM) properties. With three-dimensional (3D) Fe2O3 as a sacrificing template, we realize the construction of Fe3O4/Fe composites with tunable chemical composition, and more importantly, these composites inherit the unique 3D microstructure from their precursor. The change in chemical composition produces significant impacts on the EM functions of these composites. On the one hand, dielectric loss can be improved greatly through positive interfacial polarization and reach the peak when the mass contents of Fe3O4 and Fe are 72.1 and 27.9 wt %, respectively. On the other hand, high Fe content slightly pulls down magnetic loss in the low-frequency range but favors strong magnetic loss in the high-frequency range because of the breakthrough of Snoek's limitation. The attenuation constant reveals that dielectric loss dominates overall consumption of incident EM waves. As a result, the optimized composite, F-350 (the reduction of Fe2O3 is conducted at 350 degrees C), shows the best microwave absorption performance, whose strongest reflection loss is -56.0 dB at 17.5 GHz and the effective bandwidth can cover the frequency range of 12.0-15.5 GHz with the thickness of 1.5 mm. Furthermore, an ultrawide effective bandwidth of 15.3 GHz can be achieved with the integrated thickness of 1.0-5.0 mm. Such a performance is superior to those of many reported Fe3O4/Fe composites, and a comparative analysis manifests that good microwave absorption of F-350 is also benefited from its unique 3D architecture.

关键词： Fe3O4/Fe composites three-dimensional microstructure chemical composition interfacial polarization microwave absorption

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microstructure characteristics and effect of aging process on the mechanical properties of squeeze-cast AZ91 alloy

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JOURNAL OF ALLOYS AND COMPOUNDS 2015年 641卷 56-63页

作者： Han, G. M. Han, Z. Q. Luo, A. A. Liu, B. C. Tsinghua Univ Sch Mat Sci & Engn Key Lab Adv Mat Proc Technol Minist Educ Beijing 100084 Peoples R China Ohio State Univ Dept Mat Sci & Engn Columbus OH 43210 USA Ohio State Univ Dept Integrated Syst Engn Columbus OH 43210 USA Tsinghua Univ Dept Automot Engn State Key Lab Automot Safety & Energy Beijing 100084 Peoples R China

Quantitative microstructure information is critical to modeling and prediction of mechanical properties of structural components. In this study, the microstructure characteristics of aged squeeze-cast AZ91 alloy were investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM) analyses. Particularly, a study of the three-dimensional morphology of continuous precipitation during heat treatment was carried out using a combination of TEM and AFM. The results showed that a typical precipitate consisted of three kinds of faces, namely, broad, side, and end faces. The precipitate also presented a lath-shaped morphology with lozenge ends. Combined SEM and TEM analyses revealed quantitative information on the sizes and area number densities of precipitates after aging at different temperatures with different times. In general, the length and width of precipitates increased more rapidly than thickness during aging. The area number density initially increased and then slowly decreased because of coarsening. Furthermore, a special microstructure characteristic of the non-uniform continuous precipitation during aging was investigated using electron probe microanalysis (EPMA). The relationship between hardness response and yield strength was established. (C) 2015 Elsevier B.V. All rights reserved.

关键词： AZ91 three-dimensional microstructure Non-uniform precipitation Hardness Mechanical properties Magnesium alloy

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Synchrotron micro-computed tomography analysis of neutron-irradiated U-Mo fuel

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JOURNAL OF NUCLEAR MATERIALS 2024年 597卷

作者： Bengoa, Alejandro Figueroa Thomas, Jonova Hunter, James Kenesei, Peter Miller, Brandon D. Almer, Jonathan Okuniewski, Maria A. Purdue Univ Sch Mat Engn W Lafayette IN 47907 USA Los Alamos Natl Lab Los Alamos NM 87545 USA Argonne Natl Lab Lemont IL 60439 USA Idaho Natl Lab Idaho Falls ID 83415 USA

The three-dimensional (3D) microstructure of neutron-irradiated uranium-10 wt.% molybdenum (U-10Mo) fuel with a burn-up of 9.8 x 1021 fissions/cm3 was characterized using a novel, multi-modal synchrotron microcomputed tomography approach combining propagation-based phase-contrast enhanced and absorption contrast techniques. The porosity development, porosity interconnectedness, swelling, composition, local thickness of the zirconium (Zr) diffusion barrier, and the influence of the fuel-cladding interaction on the local composition and pore morphology, were uniquely determined in 3D. Two cuboids were produced using a focused ion beam-scanning electron microscope at the Zr diffusion barrier-fuel interface and in the bulk fuel. The bulk fuel sample swelled by 53.3 [+9.7/- 3.1]%, while the fuel near the Zr-fuel interface swelled by 63.3 [+14.7/ - 7.2]%. The average local thickness of the Zr diffusion barrier decreased by 53 %, compared to the expected preirradiated thickness. Four pore morphology regions were identified initiating parallel to the fuel-Zr interaction region: (1) an interaction layer of suppressed porosity, (2) a layer of elongated and interconnected porosity, (3) a transition zone of low porosity, and (4) a layer of unoriented porosity representative of the bulk fuel behavior. The increase in porosity near the diffusion barrier corresponded to a higher U concentration compared to that in the bulk fuel. The interconnected porosity in the fuel near the diffusion barrier was extensive and oriented parallel to the diffusion barrier, while the bulk fuel had more compact and isolated pore networks. The interaction layer, despite having suppressed porosity, was nearly 100 wt.% U. Porosity suppression at the diffusion barrier corresponds to the expected reduction in radiation -driven diffusion of Xe at the interface despite the anticipated increase in fission product nucleation originating from a higher U concentration. The novel 3D insights of the porosity, swe

关键词： Synchrotron micro-computed tomography U-Mo Swelling Porosity three-dimensional microstructure Zr diffusion barrier

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Modelling the microstructure of martensitic steels

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COMPUTATIONAL MATERIALS SCIENCE 2015年第PA期96卷 102-107页

作者： Rahnama, A. Qin, R. S. Univ London Imperial Coll Sci Technol & Med Dept Mat London SW7 2AZ England

A method based on the kinetics of crystal growth has been developed and applied to the computation of three-dimensional microstructure in austenite-martensite steels. The detailed crystallography of the transformation is used to model a realistic martensitic microstructure during the transformation without an external system of stresses. The interaction energy based on the plastic work model is taken into account to compute the variant selection in an austenitic stainless steel and formation of martensite under externally applied stress. (C) 2014 Elsevier B. V. All rights reserved.

关键词： Martensitic transformation three-dimensional microstructure Crystallography Variant selection

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three-dimensional microstructural characterization of discontinuously reinforced Ti64-TiB composites produced via blended elemental powder metallurgy

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MATERIALS CHARACTERIZATION 2009年第9期60卷 957-963页

作者： Lieberman, S. I. Gokhale, A. M. Tamirisakandala, S. Bhat, R. B. Georgia Inst Technol Sch Mat Sci & Engn Atlanta GA 30332 USA Exponent Failure Anal Associates Menlo Pk CA 94025 USA FMW Composite Syst Inc Bridgeport WV 26330 USA GE Global Res Niskayuna NY 12309 USA

three-dimensional (3D) microstructures of TiB reinforcement in two discontinuously reinforced Ti-6Al-4V (Ti64) alloy composites produced via blended elemental (BE) powder metallurgy are reconstructed from large-area high-resolution optical montage serial sections. The TiB phase in both composites shows whisker morphology with roughly hexagonal cross-sections, a unimodal size distribution, and uniform random morphological orientations. The TiB whiskers in these composites are significantly coarser compared to similar materials produced via pre-alloyed powder metallurgy but did not contain coarse primary TiB particles. (C) 2009 Elsevier Inc. All rights reserved.

关键词： TiB three-dimensional microstructure Serial sectioning Titanium metal matrix composite

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Redefinition to bilayer osmotic pump tablets as subterranean river system within mini-earth via three-dimensional structure mechanism

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Acta Pharmaceutica Sinica B 2022年第5期12卷 2568-2577页

作者： Abi Maharjan Hongyu Sun Zeying Cao Ke Li Jinping Liu Jun Liu Tiqiao Xiao Guanyun Peng Junqiu Ji Peter York Balmukunda Regmi Xianzhen Yin Jiwen Zhang Li Wu Center for Drug Delivery System Shanghai Institute of Materia MedicaChinese Academy of SciencesShanghai 201203China School of Pharmacy Key Laboratory of Molecular Pharmacology and Drug EvaluationMinistry of EducationYantai UniversityYantai 264005China University of Chinese Academy of Sciences Beijing 100049China NMPA Key Laboratory for Quality Research and Evaluation of Pharmaceutical Excipients National Institutes for Food and Drug ControlBeijing 100050China Shanghai Synchrotron Radiation Facility/Zhangjiang Lab Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China Hefei Lifeon Medication Group Hefei 230088China Center for MOST and Image Fusion Analysis Shanghai Institute of Materia MedicaChinese Academy of SciencesShanghai 201210China Maharajgung Medical Campus Institute of MedicineTribhuvan UniversityKathmandu 44606Nepal

Defining and visualizing the three-dimensional(3 D) structures of pharmaceuticals provides a new and important tool to elucidate the phenomenal behavior and underlying mechanisms of drug delivery systems. The mechanism of drug release from complex structured dosage forms, such as bilayer osmotic pump tablets, has not been investigated widely for most solid 3 D structures. In this study, bilayer osmotic pump tablets undergoing dissolution, as well as after dissolution in a desiccated solid state were examined, and visualized by synchrotron radiation micro-computed tomography(SR-μCT). In situ formed 3 D structures at different in vitro drug release states were characterized comprehensively. A distinct movement pattern of NaCl crystals from the push layer to the drug layer was observed, beneath the semi-permeable coating in the desiccated tablet samples. The 3 D structures at different dissolution time revealed that the pushing upsurge in the bilayer osmotic pump tablet was directed via peripheral“roadways”. Typically, different regions of the osmotic front, infiltration region, and dormant region were classified in the push layer during the dissolution of drug from tablet samples. According to the observed3 D microstructures, a “subterranean river model” for the drug release mechanism has been defined to explain the drug release mechanism.

关键词： Bilayer osmotic pump tablet Synchrotron radiation micro-computed tomography three-dimensional microstructure Release kinetics Void formation Peripheral“roadways” Push-pull model Subterranean river model

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