出版者・発行元：Construction and Building Materials  

This study aims to synthesize geopolymer/zeolite-P (GP-ZP) materials as a building material for environmental clean-up. High-CaO fly ash (FA), biomass ash (BMA), and metakaolin (MK) are designed as starting materials to generate geopolymeric and zeolitic materials simultaneously through geopolymerization and zeolitization using hydrothermal treatment at only 100 °C. This study explores that CaO can be quarantined in the geopolymeric structure using SiO<inf>2</inf>/Al<inf>2</inf>O<inf>3</inf> molar ratios of 6.0 and 8.0 while at lower SiO<inf>2</inf>/Al<inf>2</inf>O<inf>3</inf> molar ratios, CaO tends to precipitate various calcium compounds. Various SiO<inf>2</inf>/Al<inf>2</inf>O<inf>3</inf>, Na<inf>2</inf>O/Al<inf>2</inf>O<inf>3</inf>, CaO/Al<inf>2</inf>O<inf>3</inf>, and CaO/SiO<inf>2</inf> molar ratios are investigated using different ratios of FA and BMA mixes to explore the geopolymeric binding characteristics and evaluate the types of zeolites formed. Unmilled and milled MK are also used to partly replace FA to improve the development of porous zeolite-P materials in geopolymeric matrix. Furthermore, the differences in the material characteristics obtained from the powdered and bulk materials are compared in terms of the mineralogical composition, surface morphology, specific surface area, and cation exchange capacity. The mechanical properties of the materials are also investigated to understand the relationship between the phase development and binding properties. Hydrothermal treatment improves the mechanical properties when the FA and BMA system is used with an SiO<inf>2</inf>/Al<inf>2</inf>O<inf>3</inf> ratio of 8.0, or when the FA, BMA, and MK system is used with an SiO<inf>2</inf>/Al<inf>2</inf>O<inf>3</inf> ratio of 6.0, showing the better development of geopolymeric gel composited with zeolite-P. The environmental clean-up capability is determined using powdered and bulk material dosages of 1.0 g and 10.0 g, respectively, to remove nearly 100 % of 20 mg/L methyl orange dye.

DOI： 10.1016/j.conbuildmat.2024.139255

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記述言語：日本語   出版者・発行元：公益社団法人 日本顕微鏡学会  

<p>厚い試料の内部を可視化するのに，走査型透過型電子顕微鏡法（STEM）は結像レンズ系の色収差によって解像度が制限される透過型電子顕微鏡法と比べて優れている．そのため，走査型透過型電子顕微鏡法（STEM）は電子線トモグラフィーによる三次元構造解析にしばしば用いられる．しかし，特にフレームあたりミリ秒オーダーまたはそれ以上の高速イメージングを追求する場合，STEMの画質はノイズやアーチファクトによって顕著に劣化する．本稿では深層学習に基づくデノイズが高速STEM撮像に有効であること，また高速STEMトモグラフィーに応用できることを報告する．高速STEMトモグラフィーでは，わずか5秒の連続傾斜像収録で厚さ300 nmの鉄鋼試料からでも三次元転位配置が十分な精度で求まる．液体セルを含む比較的厚い媒質中の試料のその場観察またはオペランド観察に応用できると期待される．</p>

DOI： 10.11410/kenbikyo.59.2_52

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出版者・発行元：Microscopy and Microanalysis  

DOI： 10.1093/mam/ozae044.841

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担当区分：最終著者   記述言語：英語   出版者・発行元：Microscopy  

In-situ observation has expanded the application of transmission electron microscopy (TEM) and has made a significant contribution to materials research and development for energy, biomedical, quantum, etc. Recent technological developments related to in-situ TEM have empowered the incorporation of three-dimensional observation, which was previously considered incompatible. In this review article, we take up heating as the most commonly used external stimulus for in-situ TEM observation and overview recent in-situ TEM studies. Then, we focus on the electron tomography (ET) and in-situ heating combined observation by introducing the authors’ recent research as an example. Assuming that in-situ heating observation is expanded from two dimensions to three dimensions using a conventional TEM apparatus and a commercially available in-situ heating specimen holder, the following in-situ heating-and-ET observation procedure is proposed: (i) use a rapid heating-and-cooling function of a micro-electro-mechanical system holder; (ii) heat and cool the specimen intermittently and (iii) acquire a tilt-series dataset when the specimen heating is stopped. This procedure is not too technically challenging and can have a wide range of applications. Essential technical points for a successful 4D (space and time) observation will be discussed through reviewing the authors’ example application.

DOI： 10.1093/jmicro/dfae008

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その他リンク： https://academic.oup.com/jmicro/article-pdf/73/2/133/57186420/dfae008.pdf

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Nano Letters  

Time-resolved or time-correlation measurements using cathodoluminescence (CL) reveal the electronic and optical properties of semiconductors, such as their carrier lifetimes, at the nanoscale. However, halide perovskites, which are promising optoelectronic materials, exhibit significantly different decay dynamics in their CL and photoluminescence (PL). We conducted time-correlation CL measurements of CsPbBr<inf>3</inf> using Hanbury Brown-Twiss interferometry and compared them with time-resolved PL. The measured CL decay time was on the order of subnanoseconds and was faster than PL decay at an excited carrier density of 2.1 × 10¹⁸ cm^-3. Our experiment and analytical model revealed the CL dynamics induced by individual electron incidences, which are characterized by highly localized carrier generation followed by a rapid decrease in carrier density due to diffusion. This carrier diffusion can play a dominant role in the CL decay time for undoped semiconductors, in general, when the diffusion dynamics are faster than the carrier recombination.

DOI： 10.1021/acs.nanolett.4c00483

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： doi.org/10.1021/acs.nanolett.4c00483

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： https://doi.org/10.1093/jmicro/dfae008

記述言語：日本語   出版者・発行元：日本結晶成長学会  

<p>  Metal nanoparticles undertake sintering at a lower temperature compared to their bulk counterparts, attracting great attention in industrial applications such as printed electronics. Since nanoparticles are easy to aggregate, the three-dimensional (3D) visualization of their sintering process plays a vital role in quantifying the morphological changes during heating. However, the nanoparticles are sensitive to surface contamination, resulting in poor affinity to the 3D visualization with conventional electron beam intensity because the visualization technique requires a long beam exposure time, potentially making beam induced contamination significant. In this paper, we demonstrate our developed 3D observation scheme, including advanced image processing techniques. A sample transfer system, which enables to prevent nanoparticles from being exposed to air, and an ultra-low-electron dose observation protocol prevents surface contamination during the observation. The low-signal-to-noise ratio of acquired images is compensated by the advanced image processing techniques. The obtained 3D images of nanoparticles enable to measure the neck growth and variation of particle distance in 3D during the sintering in a quantitative way.</p>

DOI： 10.19009/jjacg.51-1-03

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

<p>Deformation-induced martensitic transformation (DIMT) can achieve both high strength and high ductility in steel materials, but the nucleation mechanism has not been clarified yet. In this study, an atomic model of the crystal orientation of materials in which DIMT was observed by in-situ transmission electron microscopy (TEM) was created and analyzed by molecular dynamics simulation to investigate the generality of the obtained dominant factors of nucleation in our previous molecular dynamics (MD) studies. As a result, it was confirmed that the nucleation sites obtained by MD simulation generally corresponded to those observed in in-situ TEM. It was also confirmed that the transformation strain is an important dominant factor in variant selection, which is consistent with the results of the previous MD studies.</p>

DOI： 10.1299/jsmecmd.2024.37.os-181920

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担当区分：最終著者   記述言語：日本語   出版者・発行元：公益社団法人 日本材料学会  

DOI： 10.2472/jsms.72.631

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Materials Science and Engineering A  

Strong attentions have been paid to low-carbon multi-phased steels showing transformation induced plasticity (TRIP) effect as good candidates for automotive applications due to their good mechanical balance between strength and ductility. However, details of complicated microstructural evolutions during thermo-mechanical processing and the roles of constituent phases on mechanical properties have not yet been fully clarified. In the present study, the formation process of multi-phased microstructures in a low alloy steel (Fe-0.2C-1.6Mn-1.4Si-1.0Ni-0.5Al: wt.%) during intercritical annealing in austenite + ferrite temperature (830 °C) and subsequent partitioning heat-treatment at lower temperature (400 °C) were systematically investigated. The phase fraction of ferrite (F), martensite (M), and retained austenite (A) significantly changed with increasing the holding time at 400 °C. It was observed that austenite transformed into ferrite during the heat-treatment at 400 °C to form newly formed ferrite having different characteristics. The ferrite in the final microstructures was categorized into four types (Type I, II, III and IV), based on their morphologies and other features. The ferrite newly formed at 400 °C (Type II, III, IV) were concluded to be formed by massive or bainitic transformation from their characteristics, i.e., morphologies, existence of surface relief, dislocations and misorientations, chemical compositions, and thermodynamic considerations. Long-range diffusion of substitutional elements did not occur in the phase transformation, but interstitial carbon diffused and enriched into austenite, resulting in large fractions of retained austenite at room temperature. Tensile mechanical properties of the obtained multi-phase steel were systematically clarified by in-situ synchrotron X-Ray diffraction. Tensile elongation increases with increasing the holding time at 400 °C, because the amount of retained austenite increased with the partitioning heat-treatment and they showed the TRIP effect through deformation-induced martensitic transformation during tensile deformation. On the other hand, the best strength-ductility balance was obtained in the specimen experienced the shortest heat-treatment at 400 °C.

DOI： 10.1016/j.msea.2023.145214

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Scripta Materialia  

The current study reveals the Hall-Petch relationship, or mean grain size control, and flow properties of equiatomic FeCoNi alloy having different grain sizes at room temperature (298 K) and cryogenic temperature (77 K). For the first time, various mean grain sizes ranging from the ultra-fine regime (0.7 μm) to the coarse grain regime (145.3 μm) were achieved in a FeCoNi alloy by high-pressure torsion and subsequent annealing. The tensile yield strength depends strongly on temperature and grain size. Hall-Petch plots demonstrate that the grain boundary strength coefficient is insensitive to the temperature, whereas friction stress increases as the temperature decreases. For all the grain sizes both strength and ductility were increased with decreasing the temperature down to 77 K. Dislocation slip is responsible for the room temperature mechanical properties. At cryogenic temperature, on the other hand, nano twinning appears as an additional deformation mechanism in addition to the dislocation slip.

DOI： 10.1016/j.scriptamat.2023.115392

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Nanoscale  

The nanoscale characterization of thermally activated solid reactions plays a pivotal role in products manufactured by nanotechnology. Recently, in situ observation in transmission electron microscopy combined with electron tomography, namely four-dimensional observation for heat treatment of nanomaterials, has attracted great interest. However, because most nanomaterials are highly reactive, i.e., oxidation during transfer and electron beam irradiation would likely cause fatal artefacts; it is challenging to perform the artifact-free four-dimensional observation. Herein, we demonstrate our development of a novel in situ three-dimensional electron microscopy technique for thermally activated solid-state reaction processes in nanoparticles (NPs). The sintering behaviour of Cu NPs was successfully visualized and analyzed in four-dimensional space-time. An advanced image processing protocol and a newly designed state-of-the-art MEMS-based heating holder enable the implementation of considerably low electron dose imaging and prevent air exposure, which is of central importance in this type of observation. The total amount of electron dose for a single set of tilt-series images was reduced to 250 e⁻ nm⁻², which is the lowest level for inorganic materials electron tomography experiments. This study evaluated the sintering behaviour of Cu NPs in terms of variations in neck growth and particle distance. A negative correlation between the two parameters is shown, except for the particle pair bound by neighbouring NPs. The nanoscale characteristic sintering behavior of neck growth was also captured in this study.

DOI： 10.1039/D3NR00992K

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Materials Science and Engineering A  

Deformation-induced martensitic transformation is a key phenomenon to manage both high strength and large ductility in low alloy multi-phase steels. Significant enhancement of strain hardening ability could be achieved by the phase transformation from soft austenite to hard martensite during deformation, which is known as transformation induced plasticity (TRIP) effect. The occurrence of TRIP effect can be controlled by austenite characteristics like carbon content, grain size and morphology. Additionally, the mechanical interaction with other phases surrounding each austenite grain during deformation would affect the stability of austenite, which has not been clarified. The current study has clarified how surrounding phases affect the mechanical stability of austenite against deformation-induced martensitic transformation. Two types of multi-phase microstructures composed of three different phases, i.e., ferrite (α) + austenite (γ) + martensite (M) and two phases of ferrite (α) + austenite (γ) were fabricated in Fe-1.6Mn-1.4Si-1.0Ni-0.5Al-0.2C, maintaining the characteristics of retained austenite nearly the same. It was found that the α+γ+M specimen exhibited slower rate of deformation-induced martensitic transformation during tensile deformation than the α+γ specimen, indicating higher austenite stability in the α+γ+M specimen. The in-situ synchrotron XRD measurements during tensile deformation revealed that there was significant stress partitioning between austenite and adjacent phases (ferrite, martensite and deformation-induced martensite), which influenced the phase transformation rate of austenite into deformation-induced martensite. Furthermore, it was also clarified by the in-situ synchrotron XRD that the austenite in the α+γ+M specimen always had higher stress than that in the α+γ specimen due to higher dislocation density in austenite introduced by martensitic transformation to form pre-existing martensite, so that higher stress was required for deformation-induced martensitic transformation in the α+γ+M specimen during tensile deformation than the α+γ specimen.

DOI： 10.1016/j.msea.2023.145089

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記述言語：英語  

DOI： 10.1186/s12916-023-02862-2

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Scientific Reports  

Abstract

Tungsten heavy alloys have been proposed as plasma facing material components in nuclear fusion reactors and require experimental investigation in their confirmation. For this purpose, a 90W–7Ni–3Fe alloy has been selected and microstructurally manipulated to present a multiphase brick-and-mortar structure of W-phase ‘bricks’ surrounded by a ductile ‘mortar’. This work draws inspiration from nature to artificially imitate the extraordinary combination of strength and stiffness exhibited by mollusks and produce a nacre-mimicking metal matrix composite capable of withstanding the extremely hostile environment of the reactor interior and maintaining structural integrity. The underlying mechanisms behind this integrity have been probed through high-resolution structural and chemical characterization techniques and have revealed chemically diffuse phase boundaries exhibiting unexpected lattice coherency. These features have been attributed to an increase in the energy required for interfacial decohesion in these systems and the simultaneous expression of high strength and toughness in tungsten heavy alloys.

DOI： 10.1038/s41598-022-26574-4

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その他リンク： https://www.nature.com/articles/s41598-022-26574-4

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Materials Science and Engineering A  

While leading a great strain hardening capability, carbon-containing twinning-induced plasticity (TWIP) steels exhibit serrations on their stress-strain curves, resulting in barriers to commercial development. Although grain refinement is believed to suppress the serrations, how the grain size, particularly in the ultrafine-grained (UFG) range, and its orientation impacting on the serrations and plastic deformation mechanism are overlooked. Here, we compared the plastic deformation behavior in fine-grained (2 μm) and ultrafine-grained (0.86 μm) specimens, in both macroscopic and microscopic behavior, using digital image correlation (DIC) and scanning transmission and transmission electron microscopy (S/TEM) techniques. Our results showed that the dominant plastic deformation mode was changed from dislocation gliding and tangling to stacking faults and deformation twinning in the grains equal to or smaller than 1 μm (ultrafine grains). This alteration is also strongly influenced by the grain orientation, i.e., the maximum resolved shear stress for slip versus twinning. The enhancement of strain localization and the inhibition of the serrations in the UFG specimens are discussed.

DOI： 10.1016/j.msea.2022.144506

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記述言語：日本語   出版者・発行元：公益社団法人 日本金属学会  

DOI： 10.2320/materia.61.870

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： https://doi.org/10.1038/s41598-022-17360-3

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Scientific Reports  

Abstract

Application of scanning transmission electron microscopy (STEM) to in situ observation will be essential in the current and emerging data-driven materials science by taking STEM’s high affinity with various analytical options into account. As is well known, STEM’s image acquisition time needs to be further shortened to capture a targeted phenomenon in real-time as STEM’s current temporal resolution is far below the conventional TEM’s. However, rapid image acquisition in the millisecond per frame or faster generally causes image distortion, poor electron signals, and unidirectional blurring, which are obstacles for realizing video-rate STEM observation. Here we show an image correction framework integrating deep learning (DL)-based denoising and image distortion correction schemes optimized for STEM rapid image acquisition. By comparing a series of distortion corrected rapid scan images with corresponding regular scan speed images, the trained DL network is shown to remove not only the statistical noise but also the unidirectional blurring. This result demonstrates that rapid as well as high-quality image acquisition by STEM without hardware modification can be established by the DL. The DL-based noise filter could be applied to in-situ observation, such as dislocation activities under external stimuli, with high spatio-temporal resolution.

DOI： 10.1038/s41598-022-17360-3

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その他リンク： https://www.nature.com/articles/s41598-022-17360-3

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： https://doi.org/10.1038/s41598-022-13878-8

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Scientific Reports  

Abstract

Observation of dynamic processes by transmission electron microscopy (TEM) is an attractive technique to experimentally analyze materials’ nanoscale phenomena and understand the microstructure-properties relationships in nanoscale. Even if spatial and temporal resolutions of real-time TEM increase significantly, it is still difficult to say that the researchers quantitatively evaluate the dynamic behavior of defects. Images in TEM video are a two-dimensional projection of three-dimensional space phenomena, thus missing information must be existed that makes image’s uniquely accurate interpretation challenging. Therefore, even though they are still a clustering high-dimensional data and can be compressed to two-dimensional, conventional statistical methods for analyzing images may not be powerful enough to track nanoscale behavior by removing various artifacts associated with experiment; and automated and unbiased processing tools for such big-data are becoming mission-critical to discover knowledge about unforeseen behavior. We have developed a method to quantitative image analysis framework to resolve these problems, in which machine learning and particle filter estimation are uniquely combined. The quantitative and automated measurement of the dislocation velocity in an Fe-31Mn-3Al-3Si autunitic steel subjected to the tensile deformation was performed to validate the framework, and an intermittent motion of the dislocations was quantitatively analyzed. The framework is successfully classifying, identifying and tracking nanoscale objects; these are not able to be accurately implemented by the conventional mean-path based analysis.

DOI： 10.1038/s41598-022-13878-8

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その他リンク： https://www.nature.com/articles/s41598-022-13878-8

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Scripta Materialia  

A combination electron backscattered diffraction and transmission electron microscopy based approach has been implemented to study the effects of purposefully introduced anisotropy in a tungsten heavy alloy (WHA) through hot-rolling. Particular attention has been paid to changes in number and proportion of various boundary types from a quantitative standpoint; incorporating qualitative behavioral observations from prior analyses to generate experimentally-validated bases for the examination and application of a microstructure which exhibits an optimal balance of strength and ductility. It is asserted that a combination of increased temperatures during rolling and additional isothermal hold time for the post-rolling annealing steps may lead to a reduction in unfavorable textural components due to rolling in the W-phase and a decrease in premature fracture due to W-W microcracking respectively. This is expected to further increase the proportion of interphase boundaries and improve the ductility of these rolled structures, producing a superior rolled WHA microstructure.

DOI： 10.1016/j.scriptamat.2022.114587

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Aluminum (Al) and titanium (Ti) are superconducting materials but their superconducting transition temperatures (𝑇c) are quite low as 1.20 and 0.39 K, respectively, while magnesium (Mg) never exhibits superconductivity. In this study, we explored new superconductors with higher 𝑇c in the Al–Mg–Ti ternary system, along with the prediction using machine learning. High-pressure torsion (HPT) is utilized to produce the superconducting states. While performing AC magnetization measurements, we found, for the first time, superconducting states with 𝑇c=4.0 and 7.3 K for a composition of Al:Ti = 1:2. The magnetic anomalies appeared more sharply when the sample was processed by HPT at 573 K than at room temperature, and the anomalies exhibited DC magnetic field dependence characteristic of superconductivity. Magnetic anomalies also appeared at ∼55 and ∼93 K, being supported by the prediction using the machine learning for the Al–Ti–O system, and this suggests that Al–Ti oxides play an important role in the advent of such anomalies but that the addition of Mg could be less effective.

DOI： https://doi.org/10.1063/5.0086694

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Journal of Applied Physics  

Aluminum (Al) and titanium (Ti) are superconducting materials but their superconducting transition temperatures (T c) are quite low as 1.20 and 0.39 K, respectively, while magnesium (Mg) never exhibits superconductivity. In this study, we explored new superconductors with higher T c in the Al-Mg-Ti ternary system, along with the prediction using machine learning. High-pressure torsion (HPT) is utilized to produce the superconducting states. While performing AC magnetization measurements, we found, for the first time, superconducting states with T c = 4.0 and 7.3 K for a composition of Al:Ti = 1:2. The magnetic anomalies appeared more sharply when the sample was processed by HPT at 573 K than at room temperature, and the anomalies exhibited DC magnetic field dependence characteristic of superconductivity. Magnetic anomalies also appeared at ∼55 and ∼93 K, being supported by the prediction using the machine learning for the Al-Ti-O system, and this suggests that Al-Ti oxides play an important role in the advent of such anomalies but that the addition of Mg could be less effective.

DOI： 10.1063/5.0086694

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記述言語：日本語   出版者・発行元：公益社団法人 日本金属学会  

DOI： 10.2320/materia.61.84

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その他リンク： https://www.jstage.jst.go.jp/article/materia/61/2/61_84/_pdf

記述言語：英語   掲載種別：研究論文（学術雑誌）  

その他リンク： https://doi.org/10.1016/j.jnoncrysol.2021.121227

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Journal of Non Crystalline Solids  

Relaxation processes during heating of both ribbon and bulk FeMo<inf>14</inf>C<inf>15</inf>B<inf>6</inf>Er<inf>x</inf>(x = 0∼2) metallic glasses were examined using valence electron energy loss spectroscopy (VEELS). The plasmon energy was decreased with increasing temperature due to thermal expansion and chemical reordering in the glasses. The chemical reordering stimulates a specific solute cluster formation; M<inf>23</inf>(CB)<inf>6</inf> solute clusters began to form above about 200 °C in both ribbon and bulk FeMo<inf>14</inf>C<inf>15</inf>B<inf>6</inf>Er<inf>x</inf> (x = 0, 0.5, 1) metallic glasses. The M<inf>23</inf>(CB)<inf>6</inf> solute clusters were only formed above 400 °C in the ribbon FeMo<inf>14</inf>C<inf>15</inf>B<inf>6</inf>Er<inf>2</inf> metallic glass, indicating inhibition of the M<inf>23</inf>(CB)<inf>6</inf> formation occurred owing to the Er-(C, B) complexes/clusters formation. The Er-(C, B) complexes/clusters were formed in the cooling process of the sample fabrication. In contrast to the ribbon sample, the M<inf>23</inf>(CB)<inf>6</inf> formation did not occur in the bulk FeMo<inf>14</inf>C<inf>15</inf>B<inf>6</inf>Er<inf>2</inf> metallic glass during heating. The amount of the Er-(C, B) complexes/clusters in the bulk sample was larger than that in the ribbon sample because of the slow cooling rate in the bulk sample fabrication. Because the solute carbon and boron atoms were mostly consumed by forming Er-(C, B) complexes/clusters in the bulk FeMo<inf>14</inf>C<inf>15</inf>B<inf>6</inf>Er<inf>2</inf> metallic glass, the M<inf>23</inf>(CB)<inf>6</inf> formation was suppressed.

DOI： 10.1016/j.jnoncrysol.2021.121227

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

A powder mixture of Al-Ti-Mg with an equal atomic fraction was subjected to severe plastic deformation using high-pressure torsion (HPT) under 6 GPa at room temperature for full consolidation. Microstructural evolution with respect to straining and annealing was examined by X-ray diffraction (XRD) analysis and high-resolution transmission electron microscopy. The XRD analysis revealed that Ti prevails in the consolidated sample and a phase transformation occurs from α phase to ω phase during HPT processing while the total fraction of the ω phase increases with straining. Grain refinement to ~100 nm was achieved through the HPT processing for 100 revolutions as well as the formation of nanograined intermetallics such as Al3Ti, AlTi3 and TiAl. The hardness gradually increases with straining, and further increases by annealing at 573 K for 1.5 h due to the formation of an Al12Mg17 phase despite the fact that the harder ω phase was reversely-transformed to the softer α phase and grains were coarsened to ~450 nm. First-principles calculations show that Al and Mg elements are dissolved into the ω − Ti during HPT processing.

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Journal of Alloys and Compounds  

A powder mixture of Al-Ti-Mg with an equal atomic fraction was subjected to severe plastic deformation using high-pressure torsion (HPT) under 6 GPa at room temperature for full consolidation. Microstructural evolution with respect to straining and annealing was examined by X-ray diffraction (XRD) analysis and high-resolution transmission electron microscopy. The XRD analysis revealed that Ti prevails in the consolidated sample and a phase transformation occurs from alpha phase to omega phase during HPT processing while the total fraction of the omega phase increases with straining. Grain refinement to similar to 100 nm was achieved through the HPT processing for 100 revolutions as well as the formation of nanograined intermetallics such as Al3Ti, AlTi3 and TiAl. The hardness gradually increases with straining, and further increases by annealing at 573 K for 1.5 h due to the formation of an Al12Mg17 phase despite the fact that the harder omega phase was reversely-transformed to the softer alpha phase and grains were coarsened to similar to 450 nm. First-principles cal-culations show that Al and Mg elements are dissolved into the omega - Ti during HPT processing. (C) 2021 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jallcom.2021.161815

Scopus

記述言語：英語   掲載種別：研究論文（学術雑誌）  

A powder mixture of Al-Ti-Mg with an equal atomic fraction was subjected to severe plastic deformation using high-pressure torsion (HPT) under 6 GPa at room temperature for full consolidation. Microstructural evolution with respect to straining and annealing was examined by X-ray diffraction (XRD) analysis and high-resolution transmission electron microscopy. The XRD analysis revealed that Ti prevails in the consolidated sample and a phase transformation occurs from α phase to ω phase during HPT processing while the total fraction of the ω phase increases with straining. Grain refinement to ~100 nm was achieved through the HPT processing for 100 revolutions as well as the formation of nanograined intermetallics such as Al3Ti, AlTi3 and TiAl. The hardness gradually increases with straining, and further increases by annealing at 573 K for 1.5 h due to the formation of an Al12Mg17 phase despite the fact that the harder ω phase was reversely-transformed to the softer α phase and grains were coarsened to ~450 nm. First-principles calculations show that Al and Mg elements are dissolved into the ω − Ti during HPT processing.

DOI： https://doi.org/10.1038/s41598-021-99914-5

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Scanning transmission electron microscopy (STEM) is suitable for visualizing the inside of a relatively thick specimen than the conventional transmission electron microscopy, whose resolution is limited by the chromatic aberration of image forming lenses, and thus, the STEM mode has been employed frequently for computed electron tomography based three-dimensional (3D) structural characterization and combined with analytical methods such as annular dark field imaging or spectroscopies. However, the image quality of STEM is severely suffered by noise or artifacts especially when rapid imaging, in the order of millisecond per frame or faster, is pursued. Here we demonstrate a deep-learning-assisted rapid STEM tomography, which visualizes 3D dislocation arrangement only within five-second acquisition of all the tilt-series images even in a 300 nm thick steel specimen. The developed method offers a new platform for various in situ or operando 3D microanalyses in which dealing with relatively thick specimens or covering media like liquid cells are required.

DOI： 10.1038/s41598-021-99914-5

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/acsabm.1c00826

記述言語：英語   掲載種別：研究論文（学術雑誌）  

その他リンク： https://doi.org/10.1021/acsabm.1c00826

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The underlying mechanism of discontinuous yielding behavior in an ultrafine-grained (UFG) Fe-31Mn-3Al-3Si (wt.%) austenitic TWIP steel was investigated by the use of advanced TEM technique with taking the plastic deformation mechanisms and their correlation with grains size near the macroscopic yield point into account. Typical yield drop mechanisms such as the dislocation locking by the Cottrell atmosphere due to the presence of interstitial impurities cannot explain the origin of this phenomenon in the UFG high-Mn austenitic TWIP steel. Here, we experimentally revealed that the plastic deformation mechanisms in the early stage of deformation, around the macroscopic yield point, show an obvious association with grain size. More specifically, the main mechanism shifts from the conventional slip in grain interior to twinning nucleated from grain boundaries with decreasing the grain size down to less than 1 μm. Our observation indicates that the grain size dependent deformation mechanisms transition is also deeply associated with the discontinuous yielding behavior as it could govern the changes in the grain interior dislocation density of mobile dislocations around the macroscopic yield point.

DOI： https://doi.org/10.1016/j.jmst.2021.01.031

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Some of ultrafine-grained (UFG) metals including UFG twinning induced plasticity (TWIP) steels have been found to overcome the paradox of strength and ductility in metals benefiting from their unique deformation modes. Here, this study provides insights into the atomistic process of deformation twin nucleation at Σ3{111} twin boundaries, the dominant type of grain boundary in this UFG high manganese TWIP steel. In response to the applied tensile stresses, grain boundary sliding takes place which changes the structure of coherent Σ3{111} twin boundary from atomistically smooth to partly defective. High resolution transmission electron microscopy demonstrates that the formation of disconnection on Σ3{111} twin boundaries is associated with the motion of Shockley partial dislocations on the boundaries. The twin boundary disconnections act as preferential nucleation sites for deformation twin that is a characteristic difference from the coarse-grained counterpart, and is likely correlated with the lethargy of grain interior dislocation activities, frequently seen in UFG metals. The deformation twin nucleation behavior will be discussed based on in-situ TEM deformation experiments and nanoscale strain distribution analyses results.

DOI： 10.1038/s41598-021-98875-z

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The underlying mechanism of discontinuous yielding behavior in an ultrafine-grained (UFG) Fe-31Mn-3Al-3Si (wt.%) austenitic TWIP steel was investigated by the use of advanced TEM technique with taking the plastic deformation mechanisms and their correlation with grains size near the macroscopic yield point into account. Typical yield drop mechanisms such as the dislocation locking by the Cottrell atmosphere due to the presence of interstitial impurities cannot explain the origin of this phenomenon in the UFG high-Mn austenitic TWIP steel. Here, we experimentally revealed that the plastic deformation mechanisms in the early stage of deformation, around the macroscopic yield point, show an obvious association with grain size. More specifically, the main mechanism shifts from the conventional slip in grain interior to twinning nucleated from grain boundaries with decreasing the grain size down to less than 1 μm. Our observation indicates that the grain size dependent deformation mechanisms transition is also deeply associated with the discontinuous yielding behavior as it could govern the changes in the grain interior dislocation density of mobile dislocations around the macroscopic yield point.

DOI： 10.1016/j.jmst.2021.01.031

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Some of ultrafine-grained (UFG) metals including UFG twinning induced plasticity (TWIP) steels have been found to overcome the paradox of strength and ductility in metals benefiting from their unique deformation modes. Here, this study provides insights into the atomistic process of deformation twin nucleation at Σ3{111} twin boundaries, the dominant type of grain boundary in this UFG high manganese TWIP steel. In response to the applied tensile stresses, grain boundary sliding takes place which changes the structure of coherent Σ3{111} twin boundary from atomistically smooth to partly defective. High resolution transmission electron microscopy demonstrates that the formation of disconnection on Σ3{111} twin boundaries is associated with the motion of Shockley partial dislocations on the boundaries. The twin boundary disconnections act as preferential nucleation sites for deformation twin that is a characteristic difference from the coarse-grained counterpart, and is likely correlated with the lethargy of grain interior dislocation activities, frequently seen in UFG metals. The deformation twin nucleation behavior will be discussed based on in-situ TEM deformation experiments and nanoscale strain distribution analyses results.

DOI： https://doi.org/10.1038/s41598-021-98875-z

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Tensile mechanical properties of fully recrystallized TWIP steel specimens having various grain sizes (d) ranging from 0.79 μm to 85.6 μm were investigated. It was confirmed that the UFG specimens having the mean grain sizes of 1.5 μm or smaller abnormally showed discontinuous yielding characterized by a clear yield-drop while the specimens having grain sizes larger than 2.4 μm showed normal continuous yielding. In-situ synchrotron radiation XRD showed dislocation density around yield-drop in the UFG specimen quickly increased. ECCI observations revealed the nucleation of deformation twins and stacking faults from grain boundaries in the UFG specimen around yielding. Although it had been conventionally reported that the grain refinement suppresses deformation twinning in FCC metals and alloys, the number density of deformation twins in the 0.79 μm grain-sized specimen was much higher than that in the specimens with grain sizes of 4.5 μm and 15.4 μm. The unusual change of yielding behavior from continuous to discontinuous manner by grain refinement could be understood on the basis of limited number of free dislocations in each ultrafine grain. The results indicated that the scarcity of free dislocations in the recrystallized UFG specimens changed the deformation and twinning mechanisms in the TWIP steel.

DOI： https://doi.org/10.1038/s41598-021-94800-6

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Tensile mechanical properties of fully recrystallized TWIP steel specimens having various grain sizes (d) ranging from 0.79 μm to 85.6 μm were investigated. It was confirmed that the UFG specimens having the mean grain sizes of 1.5 μm or smaller abnormally showed discontinuous yielding characterized by a clear yield-drop while the specimens having grain sizes larger than 2.4 μm showed normal continuous yielding. In-situ synchrotron radiation XRD showed dislocation density around yield-drop in the UFG specimen quickly increased. ECCI observations revealed the nucleation of deformation twins and stacking faults from grain boundaries in the UFG specimen around yielding. Although it had been conventionally reported that the grain refinement suppresses deformation twinning in FCC metals and alloys, the number density of deformation twins in the 0.79 μm grain-sized specimen was much higher than that in the specimens with grain sizes of 4.5 μm and 15.4 μm. The unusual change of yielding behavior from continuous to discontinuous manner by grain refinement could be understood on the basis of limited number of free dislocations in each ultrafine grain. The results indicated that the scarcity of free dislocations in the recrystallized UFG specimens changed the deformation and twinning mechanisms in the TWIP steel.

DOI： 10.1038/s41598-021-94800-6

記述言語：英語   掲載種別：研究論文（学術雑誌）  

In polycrystalline materials, grain boundaries are known to be a critical microstructural component controlling material’s mechanical properties, and their characters such as misorientation and crystallographic boundary planes would also influence the dislocation dynamics. Nevertheless, many of generally used mechanistic models for deformation twin nucleation in fcc metal do not take considerable care of the role of grain boundary characters. Here, we experimentally reveal that deformation twin nucleation occurs at an annealing twin (Σ3{111}) boundary in a high-Mn austenitic steel when dislocation pile-up at Σ3{111} boundary produced a local stress exceeding the twining stress, while no obvious local stress concentration was required at relatively high-energy grain boundaries such as Σ21 or Σ31. A periodic contrast reversal associated with a sequential stacking faults emission from Σ3{111} boundary was observed by in-situ transmission electron microscopy (TEM) deformation experiments, proving the successive layer-by-layer stacking fault emission was the deformation twin nucleation mechanism, different from the previously reported observations in the high-Mn steels. Since this is also true for the observed high Σ-value boundaries in this study, our observation demonstrates the practical importance of taking grain boundary characters into account to understand the deformation twin nucleation mechanism besides well-known factors such as stacking fault energy and grain size.

DOI： 10.1038/s41598-021-87811-w

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.actamat.2020.116523

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1371/journal.pone.0241603

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1038/s41563-020-00833-z

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1371/journal.pone.0241603

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1246/bcsj.20200134

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The combination of in-situ and three-dimensional (3D) in transmission electron microscopy (TEM) is one of the emerging topics of recent advanced electron microscopy research. However, to date, there have been only handful examples of in-situ 3D TEM for material deformation dynamics. In this article, firstly, the authors briefly review technical developments in fast tilt-series dataset acquisition, which is a crucial technique for in-situ electron tomography (ET). Secondly, the authors showcase a recent successful example of in-situ specimen-straining and ET system development and its applications to the deformation dynamics of crystalline materials. The system is designed and developed to explore, in real-time and at sub-microscopic levels, the internal behavior of polycrystalline materials subjected to external stresses, and not specifically targeted for atomic resolution (although it may be possible). Technical challenges toward the in-situ ET observation of 3D dislocation dynamics are discussed for commercial structural crystalline materials, including some of the early studies on in-situ ET imaging and 3D modeling of dislocation dynamics. A short summary of standing technical issues and a proposed guideline for further development in the 3D imaging method for dislocation dynamics are then discussed.

DOI： 10.1016/j.cossms.2020.100850

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Time-resolved imaging of molecules and materials made of light elements is an emerging field of transmission electron microscopy (TEM), and the recent development of direct electron detection cameras, capable of taking as many as 1,600 fps, has potentially broadened the scope of the time-resolved TEM imaging in chemistry and nanotechnology. However, such a high frame rate reduces electron dose per frame, lowers the signal-to-noise ratio (SNR), and renders the molecular images practically invisible. Here, we examined image noise reduction to take the best advantage of fast cameras and concluded that the Chambolle total variation denoising algorithm is the method of choice, as illustrated for imaging of a molecule in the 1D hollow space of a carbon nanotube with ~1 ms time resolution. Through the systematic comparison of the performance of multiple denoising algorithms, we found that the Chambolle algorithm improves the SNR by more than an order of magnitude when applied to TEM images taken at a low electron dose as required for imaging at around 1,000 fps.

DOI： https://doi.org/10.1017/S1431927620001750[Opens in a new window]

記述言語：英語   掲載種別：研究論文（学術雑誌）  

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DOI： 10.1017/s1431927620001750

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1080/14786435.2020.1741044

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s11661-019-05345-3

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1093/jmicro/dfaa002

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： https://doi.org/10.1080/14786435.2020.1741044

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： https://doi.org/10.1093/jmicro/dfaa002

その他リンク： https://doi.org/10.1093/jmicro/dfaa002

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 185

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.actamat.2019.12.008

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Miniaturized machines have open up a new dimension of chemistry, studied usually as an average over numerous molecules or for a single molecule bound on a robust substrate. Mechanical motions at a single molecule level, however, are under quantum control, strongly coupled with fluctuations of its environment-a system rarely addressed because an efficient way of observing the nanomechanical motions in real time is lacking. Here, we report sub-millisecond sub-A precision in situ video imaging of a single fullerene molecule shuttling, rotating, and interacting with a vibrating carbon nanotube at 0.625 milliseconds(ms)/frame or 1600 fps, using an electron microscope, a fast camera, and a denoising algorithm. We have achieved in situ observation of the mechanical motions of a molecule coupled with vibration of a carbon nanotube with standard error as small as 0.9 millisecond in time and 0.01 nm in space. We have revealed rich molecular dynamics, where motions are non-linear, stochastic and often non-repeatable, and a work and energy relationship at a molecular level previously undetected by time-averaged measurements or microscopy. The molecular video recording at a 1600-fps rate exceeds by 100 times the previous records of continuous recording of molecular motions.

DOI： 10.1246/bcsj.20200134

その他リンク： https://chemrxiv.org/articles/Real-Time_Video_Imaging_of_Mechanical_Motions_of_a_Single_Molecular_Shuttle/10029194

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.jpcs.2019.109139

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s11661-019-05345-3

その他リンク： https://doi.org/10.1007/s11661-019-05345-3

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/acs.macromol.9b02075

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s10853-019-03762-8

記述言語：英語   掲載種別：研究論文（学術雑誌）  

その他リンク： https://doi.org/10.1016/j.gca.2019.05.011

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.gca.2019.05.011

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.2138/am-2019-6848

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/acsmacrolett.9b00136

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1126/science.aau8299

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： https://doi.org/10.1002/aws2.1114

その他リンク： https://awwa.onlinelibrary.wiley.com/doi/abs/10.1002/aws2.1114

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1002/aws2.1114

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：その他   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/acsaem.8b00474

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1038/s41598-018-25122-3

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.commatsci.2017.08.012

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語  

DOI： 10.1002/9783527808465.emc2016.6262

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1093/jmicro/dfw109

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Deformation and dissolution behaviors are important characteristics of soft dispersion particles in steel to improve the deformability of high strength steel sheets by controlling the work hardening/softening and fracture processes associated with particle dispersion strengthening. In this study, the deformation and dissolution behaviors of epsilon-Cu precipitate particles in a ferrite matrix were investigated to understand how relatively soft dispersion particles influence mechanical responses of the steel compared to hard dispersion particles such as alloy carbides. 35 nm diameter nearly spherical e-Cu particles were initially elongated along the rolling direction by cold rolling, and then these were partly dissolved into the ferrite matrix as the equivalent strain increased. The dissolution of the Cu particles was suggested to be caused by a dynamic partitioning of Cu atoms from the precipitates into the matrix by dislocation shearing at the particle tip sharpened by severe cold working. Simultaneously, the contribution of the epsilon-Cu particles to the dispersion strengthening appeared to be decreased with increasing dislocation density in the matrix during cold rolling. The dislocation density and other defects in the epsilon-Cu particles also increased and the particle/matrix interfaces were serrated or became indistinct as deformation progressed. The morphology, internal defects, and interface structure changes of fine dispersion particles and their correlation with mechanical responses of the alloy are discussed in reference to an identically processed, hard particles dispersed Fe-V binary alloy. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.actamat.2016.03.018

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.gca.2016.02.007

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.jece.2016.01.012

記述言語：その他   掲載種別：研究論文（学術雑誌）  

DOI： 10.1089/ees.2015.0226

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1093/jmicro/dfv021

記述言語：英語  

DOI： 10.2136/sssabookser10.c44

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.2138/am-2015-5287

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s11661-015-2936-y

記述言語：英語   掲載種別：研究論文（学術雑誌）  

We systematically investigate stress-strain behavior of ferrite and bainite with nano-sized vanadium carbides in low carbon steels; the ferrite samples were obtained through austenite/ferrite transformation accompanied with interphase precipitation and the bainite samples were via austenite/bainite transformation with subsequent aging. The stress-strain curves of both samples share several common features, i.e. high yield stress, relatively low work hardening and sufficient tensile elongation. Strengthening contributions from solute atoms, grain boundaries, dislocations and precipitates are calculated based on the structural parameters, and the calculation result is compared with the experimentally-obtained yield stress. The contributions from solute atoms and grain boundaries are simply additive, whereas those from dislocations and precipitates should be treated by taking the square root of the sum of the squares of two values. Nano-sized carbides may act as sites for dislocation multiplication in the early stage of deformation, while they may enhance dislocation annihilation in the later stage of deformation. Such enhanced dynamic recovery might be the reason for a relatively large elongation in both ferrite and bainite samples.

DOI： 10.1016/j.actamat.2014.10.010

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.actamat.2014.04.048

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.gca.2012.10.029

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.gca.2012.05.008

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1039/c2em10809g

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.ssi.2011.06.013

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1111/j.1551-2916.2011.04444.x

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1111/j.1551-2916.2010.04154.x

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/es101565j

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1071/en09111

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1063/1.3116715

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1088/0957-4484/19/44/445610

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.corsci.2008.05.022

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.icarus.2008.02.021

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.jcat.2007.08.007

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.jcat.2007.06.011

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.jcat.2007.06.001

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s11244-007-0304-x

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.corsci.2006.03.002

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.actamat.2004.02.038

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1063/1.1704865

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1103/physrevlett.91.265504

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/s1359-6454(02)00530-x

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Relationships between volume plasmon excitations and mechanical properties of various materials are considered. Based on systematic evaluation of available data, correlations between the volume plasmon energy, E_p, Young's modulus, Y_m, bulk modulus, B_m, shear modulus, G_m, and microhardness, H_m, are established. The resulting correlations indicate that plasmon energies potentially can be used to predict and/or determine the local mechanical properties of technologically important materials, such as metal alloys, semiconductors, and ceramics at the nanometer level.

DOI： 10.1017/s1431927602020299

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：その他   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：日本語  

Charactrization of Fine Precpitates in 17-4 PH Stainless Steel

DOI： 10.2320/materia.39.969

記述言語：英語   掲載種別：研究論文（学術雑誌）  

開催年月日： 2023年12月

記述言語：日本語   会議種別：公開講演，セミナー，チュートリアル，講習，講義等  

開催地：産総研先進パワーエレクトロニクス研究センター   国名：日本国  

開催年月日： 2023年10月

記述言語：英語   会議種別：口頭発表（基調）  

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開催年月日： 2023年8月

記述言語：日本語   会議種別：公開講演，セミナー，チュートリアル，講習，講義等  

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開催年月日： 2021年9月 - 2021年10月

記述言語：英語   会議種別：口頭発表（一般）  

開催地：オンライン   国名：日本国  

開催年月日： 2020年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：オンライン   国名：日本国  

開催年月日： 2020年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：オンライン   国名：日本国  

記述言語：日本語   会議種別：口頭発表（一般）  

国名：日本国  

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記述言語：英語   会議種別：口頭発表（招待・特別）  

国名：日本国  

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記述言語：英語   会議種別：口頭発表（招待・特別）  

国名：日本国  

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記述言語：英語   会議種別：ポスター発表  

国名：日本国  

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記述言語：英語  

国名：日本国  

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記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

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記述言語：英語   会議種別：ポスター発表  

国名：日本国  

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記述言語：英語   会議種別：公開講演，セミナー，チュートリアル，講習，講義等  

国名：日本国  

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記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

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記述言語：日本語   会議種別：口頭発表（基調）  

国名：日本国  

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記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

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記述言語：日本語   会議種別：口頭発表（一般）  

国名：日本国  

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記述言語：日本語   会議種別：口頭発表（一般）  

国名：日本国  

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記述言語：日本語   会議種別：口頭発表（一般）  

国名：日本国  

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記述言語：日本語   会議種別：ポスター発表  

国名：日本国  

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記述言語：日本語   会議種別：ポスター発表  

国名：日本国  

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記述言語：日本語   会議種別：口頭発表（一般）  

国名：日本国  

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記述言語：日本語   会議種別：口頭発表（一般）  

国名：日本国  

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記述言語：日本語   会議種別：口頭発表（一般）  

国名：日本国  

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記述言語：日本語   会議種別：口頭発表（一般）  

国名：日本国  

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記述言語：日本語   会議種別：口頭発表（一般）  

国名：日本国  

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記述言語：英語  

国名：日本国  

記述言語：日本語  

国名：日本国  

記述言語：日本語  

国名：日本国  

記述言語：英語  

国名：日本国  

記述言語：英語  

国名：日本国  

記述言語：英語  

国名：日本国  

記述言語：英語  

国名：日本国  

記述言語：英語  

国名：日本国  

記述言語：日本語  

国名：日本国  

記述言語：日本語  

国名：日本国  

記述言語：日本語  

国名：日本国  

記述言語：英語  

国名：日本国  

記述言語：日本語  

国名：日本国  

記述言語：日本語  

国名：日本国  

記述言語：日本語  

国名：日本国  

記述言語：英語  

国名：日本国  

記述言語：英語  

国名：日本国  

記述言語：日本語  

国名：日本国  

記述言語：日本語  

国名：日本国  

記述言語：日本語  

国名：日本国  

記述言語：日本語  

国名：日本国  

記述言語：英語  

国名：日本国  

Size-Dependent Luminescence of Submicron-Sized CsPbBr3 Crystals

記述言語：英語  

国名：日本国  

記述言語：日本語  

国名：日本国  

記述言語：日本語  

国名：日本国  

Exploration of Superconductivity in Three-elements Light Metal System～Proposing Exploration Strategy and Assuming Superconducting Components by Machine Learning～

記述言語：日本語   掲載種別：記事・総説・解説・論説等（学術雑誌）  

DOI： https://doi.org/10.2320/materia.61.84

記述言語：日本語  

Recent Studies on TEM/STEM Tomography

DOI： 10.2320/materia.61.84

出版者・発行元：Materials Transactions  

DOI： 10.2320/matertrans.MPR2022901

Scopus

記述言語：日本語  

Realizing Structural Metallic Materials with Both High Strength and Large Ductility through Nucleation Control of Different Deformation Modes

DOI： 10.2320/materia.60.8

記述言語：英語   掲載種別：記事・総説・解説・論説等（学術雑誌）  

Transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) enable the visualization of three-dimensional (3D) microstructures ranging from atomic to micrometer scales using 3D reconstruction techniques based on computed tomography algorithms. This 3D microscopy method is called electron tomography (ET) and has been utilized in the fields of materials science and engineering for more than two decades. Although atomic resolution is one of the current topics in ET research, the development and deployment of intermediate-resolution (non-atomic-resolution) ET imaging methods have garnered considerable attention from researchers. This research trend is probably not irrelevant due to the fact that the spatial resolution and functionality of 3D imaging methods of scanning electron microscopy (SEM) and X-ray microscopy have come to overlap with those of ET. In other words, there may be multiple ways to carry out 3D visualization using different microscopy methods for nanometer-scale objects in materials. From the above standpoint, this review paper aims to (i) describe the current status and issues of intermediate-resolution ET with regard to enhancing the effectiveness of TEM/STEM imaging and (ii) discuss promising applications of state-of-the-art intermediate-resolution ET for materials research with a particular focus on diffraction contrast ET for crystalline microstructures (superlattice domains and dislocations) including a demonstration of in situ dislocation tomography.

DOI： https://doi.org/10.1093/jmicro/dfaa002

その他リンク： https://academic.oup.com/jmicro/article/69/3/141/5770850?login=true

記述言語：日本語   掲載種別：記事・総説・解説・論説等（学術雑誌）  

DOI： https://doi.org/10.11410/kenbikyo.54.1_44

記述言語：日本語  

Placticals and Trends of Electron Tomography for Materials Research

DOI： 10.2320/materia.57.589

記述言語：日本語  

Electron Tomography with in-situ Deformation

DOI： 10.2320/materia.55.595

記述言語：日本語  

A Medium-term Outlook for U.S. Structural Metallic Materials Research

DOI： 10.2320/materia.51.462

記述言語：日本語  

Microstructural Analysis of Mechanically Milled Nanocrystalline Fe Powder

DOI： 10.2320/materia.42.877

記述言語：日本語  

Living in a small southern United States town

記述言語：日本語  

Elementary analysis of quenched-in vacancies in Al-Cu and Al-Cu-Mg alloys studied by positron annihilation methods