検索対象:     
報告書番号:
※ 半角英数字
 年 ~ 
 年
検索結果: 129 件中 1件目~20件目を表示

発表形式

Initialising ...

選択項目を絞り込む

掲載資料名

Initialising ...

発表会議名

Initialising ...

筆頭著者名

Initialising ...

キーワード

Initialising ...

使用言語

Initialising ...

発行年

Initialising ...

開催年

Initialising ...

選択した検索結果をダウンロード

論文

Recent progress on practical materials study by Bragg edge imaging at J-PARC

及川 健一; Su, Y.; 鬼柳 亮嗣; 川崎 卓郎; 篠原 武尚; 甲斐 哲也; 廣井 孝介; Harjo, S.; Parker, J. D.*; 松本 吉弘*; et al.

Physica B; Condensed Matter, 551, p.436 - 442, 2018/12

 パーセンタイル:100(Physics, Condensed Matter)

We are promoting for practical product observation by the energy-resolved neutron imaging method using high-intensity pulsed neutrons at J-PARC, under the Photon and Quantum Basic Research Coordinated Development Program from the Ministry of Education, Culture, Sports, Science and Technology, Japan. Bragg edge imaging, one of the energy-resolved neutron imaging methods for visualizing material properties, was applied to feasibility study of the temperature distribution of copper rod, complementary study of the texture and strain distribution of bent steel plates using neutron diffraction and EBSD, and so on. Outline of results obtained by these imaging experiments will be presented.

論文

Testing of time-of-flight neutron diffraction imaging using a high-resolution scintillator detector with wavelength-shifting fibers

川崎 卓郎; 中村 龍也; Gong, W.*; 及川 健一

Physica B; Condensed Matter, 551, p.460 - 463, 2018/12

 パーセンタイル:100(Physics, Condensed Matter)

Neutron diffraction is widely used for the investigation of lattice strain, texture and phase transformation in bulk materials. Although the distributions of these characteristics can be obtained by scanning the sample, the spatial resolution of the measurement is limited. Recently, Bragg-edge imaging technique is developed and adopted for the evaluations of lattice strain, crystal orientation and phase distributions in polycrystalline engineering materials such as steel. On the other hand, neutron diffraction imaging has a potential to be another technique for such purpose. Diffraction imaging at a pulsed neutron source requires a counting type two-dimensional position sensitive detector with high spatial resolution. We developed prototype imaging detector with wavelength-shifting fiber (WLSF) readout, and tried to observe sub grains in the b-Sn single crystal and grain distribution in the coarse-grained steel plate at NOBORU (BL10) of J-PARC MLF.

論文

Effect of gauge volume on strain measurement in rock materials using time-of-flight neutron diffraction

阿部 淳*; 関根 孝太郎*; Harjo, S.; 川崎 卓郎; 相澤 一也

Physica B; Condensed Matter, 551, p.283 - 286, 2018/12

 パーセンタイル:100(Physics, Condensed Matter)

Our previous neutron diffraction measurements investigated strain accumulation mechanism(s) in rock materials under uniaxial compression. This technique, when applied to metallic materials, is suffered by surface effects, gauge volume size effects, and/or incident beam divergence that induce pseudo-strain. Knowledge of the pseudo-strain is therefore necessary for precise evaluation of strain value in a stressed rock material. This work investigated the effects of gauge volume and incident neutron beam divergence on pseudo-strain in rock materials via neutron diffraction experiments performed on three types of sandstone. Spurious peak shifts appeared depending on the gauge volume or incident neutron beam divergence. These peak shifts were inferred to be derived from the difference between a neutron-weighted center of gravity position and a geometric center of the gauge volume position. However, changing the gauge volume height did not cause shift in the peak position.

論文

Deformation of CoCrFeNi high entropy alloy at large strain

Wang, B.*; He, H.*; Naeem, M.*; Lan, S.*; Harjo, S.; 川崎 卓郎; Nie, Y.*; Wang, X.-L.*; 他7名*

Scripta Materialia, 155, p.54 - 57, 2018/10

 被引用回数:5 パーセンタイル:15.24(Nanoscience & Nanotechnology)

The deformation behavior of an equi-atomic face-centered-cubic CoCrFeNi high entropy alloy was investigated by in-situ neutron diffraction under tensile loading up to 40% applied strain. A three-stage deformation behavior was fully captured by lattice strain and texture evolution. In spite of the chemical complexity, the deformation in CoCrFeNi is dominated by dislocation activities. Analysis of diffraction and microscopy data shows that the deformation progresses from dislocation slip to severe entanglement, where a sharp increase in dislocation density was observed. The neutron diffraction data, corroborated by transmission electron microscopy analysis, provided microscopic insights of the previously reported three-stage hardening behavior.

論文

Stroboscopic time-of-flight neutron diffraction during cyclic testing using the event data recording system at J-PARC

川崎 卓郎; 稲村 泰弘; 伊藤 崇芳*; 中谷 健; Harjo, S.; Gong, W.*; 相澤 一也

Journal of Applied Crystallography, 51(3), p.630 - 634, 2018/06

 被引用回数:1 パーセンタイル:47.84(Chemistry, Multidisciplinary)

A time-resolved time-of-flight neutron diffraction technique to characterize the structural properties of materials during cyclic tests has been developed. By adopting the developed technique, the behaviors of the crystal lattice and domains of the piezoelectric material in a multilayer-type piezoelectric actuator driven by a cyclic electric field were evaluated. The variation in diffraction intensity during the application of a cyclic electric field was obtained successfully, and the hysteresis-like behaviors of both the lattice strain and the 90$$^{circ}$$ domain switching were revealed.

論文

中性子回折法による曲げとせん断を受けた鉄筋コンクリートの付着応力度の非破壊評価

鈴木 裕士; 楠 浩一*; 佐竹 高祐*; 兼松 学*; 小山 拓*; 丹羽 章暢*; 椛山 健二*; 向井 智久*; 川崎 卓郎; Harjo, S.

非破壊検査, 67(4), p.180 - 186, 2018/04

本研究では、中性子回折法により二次元的に配筋した主筋およびせん断補強筋の応力分布を測定することにより、曲げモーメントを負荷した鉄筋コンクリート梁試験体の付着挙動を評価した。その結果、周囲のコンクリートによる主筋横方向の変形拘束が無視できるほどに小さいという前提に基づき、試験体を回転することなく、曲げ付着挙動の評価の鍵となる主筋の付着応力度分布の変化、およびせん断補強筋の軸応力変化の定量評価に成功した。ひずみゲージ法により測定されたコンクリートの巨視的な変形挙動との比較により,載荷に伴う曲げひび割れの発生と、それに続くせん断ひび割れの発生が、その周辺における付着劣化の原因となり、それに伴い主筋軸応力分布が変化することを確認した。本研究により、中性子応力測定技術は、鉄筋コンクリート梁の曲げ付着挙動の評価にも有効な手段であることを確認した。

論文

In situ neutron diffraction study on microstructure evolution during thermo-mechanical processing of medium manganese steel

中村 良彦*; 柴田 曉伸*; Gong, W.*; Harjo, S.; 川崎 卓郎; 伊東 篤志*; 辻 伸泰*

Proceedings of International Conference on Martensitic Transformations: Chicago, p.155 - 158, 2018/04

The microstructure evolution of medium manganese steel (Fe-5Mn-2Si-0.1C (wt%)) during thermo-mechanical processing in ferrite + austenite two-phase region was investigated by in situ neutron diffraction analysis and microstructure observations. When the specimens were isothermally held at a temperature of 700$$^circ$$C, the fraction of reversely transformed austenite increased gradually with an increase in the isothermal holding time. However, it did not reach the equilibrium fraction of austenite even after isothermal holding for 10 ks. On the other hand, the fraction of reversely transformed austenite increased rapidly after the compressive deformation at a strain rate of 1 s$$^{-1}$$ at 700$$^circ$$C and reached the equilibrium state during subsequent isothermal holding for around 3 ks.

論文

Effect of hydrogenation conditions on the microstructure and mechanical properties of zirconium hydride

牟田 浩明*; 西金 遼二*; 安藤 祐介*; 松永 純治*; 坂本 寛*; Harjo, S.; 川崎 卓郎; 大石 佑治*; 黒崎 健*; 山中 伸介*

Journal of Nuclear Materials, 500, p.145 - 152, 2018/03

 被引用回数:1 パーセンタイル:38.14(Materials Science, Multidisciplinary)

Precipitation of brittle zirconium hydrides deteriorate the fracture toughness of the fuel cladding tubes of light water reactor. In the present study, to elucidate relationship between mechanical properties and microstructure, two $$delta$$ -phase zirconium hydrides and one $$varepsilon$$-phase zirconium hydride were carefully fabricated considering volume changes at the metal-to-hydride transformation. The $$delta$$-hydride that was fabricated from $$alpha$$-zirconium exhibits numerous inner cracks due to the large volume change. Analyses of the neutron diffraction pattern and electron backscatter diffraction (EBSD) data show that the sample displays significant stacking faults in the ${111}$ plane and in the pseudo-layered microstructure. On the other hand, the $$delta$$-hydride sample fabricated from $$beta$$-zirconium at a higher temperature displays equiaxed grains and no cracks.

論文

Materials and Life Science Experimental Facility (MLF) at the Japan Proton Accelerator Research Complex, 2; Neutron scattering instruments

中島 健次; 川北 至信; 伊藤 晋一*; 阿部 淳*; 相澤 一也; 青木 裕之; 遠藤 仁*; 藤田 全基*; 舟越 賢一*; Gong, W.*; et al.

Quantum Beam Science (Internet), 1(3), p.9_1 - 9_59, 2017/12

J-PARC物質・生命科学実験施設の中性子実験装置についてのレビューである。物質・生命科学実験施設には23の中性子ビームポートがあり21台の装置が設置されている。それらは、J-PARCの高性能な中性子源と最新の技術を組み合わせた世界屈指の実験装置群である。このレビューでは、装置性能や典型的な成果等について概観する。

論文

Changes of dislocation density and dislocation arrangement during tensile deformation in lath martensitic steels

Harjo, S.; 川崎 卓郎; 諸岡 聡

Advanced Experimental Mechanics, 2, p.112 - 117, 2017/10

To understand strengthening mechanism in lath martensitic steels, in situ neutron diffractions during tensile deformation for 22SiMn2TiB steel and Fe-18Ni alloy were performed using TAKUMI of J-PARC. Profile analyses were performed using Convolutional Multiple Whole Profile (CMWP) fitting and Williamson-Hall (W-H) methods. As results, the dislocation densities as high as 10$$^{15}$$ m$$^{-2}$$ in the as-quenched states of both steels were determined hardly to change or slightly increase by the CMWP method. The reliability of the dislocation density obtained from the W-H method was low, because the whole profile was not considered for the analysis. In the former method, the values of parameter M related to dislocations arrangement was found to decrease rapidly for both steels at the beginning of plastic deformation. Hence, high work hardening in the lath martensitic steels was considered due to the dislocations rearrangements with plastic deformation.

論文

種々な方法によるMn-Si-C鋼の残留オーステナイト体積率測定の比較

友田 陽*; 関戸 信彰*; 徐 平光; 川崎 卓郎; Harjo, S.; 田中 雅彦*; 篠原 武尚; Su, Y.; 谷山 明*

鉄と鋼, 103(10), p.570 - 578, 2017/10

 被引用回数:1 パーセンタイル:76.21(Metallurgy & Metallurgical Engineering)

Various methods were employed to measure the austenite volume fraction in a 1.5Mn-1.5Si-0.2C steel. It has been confirmed that the volume fractions determined by transmission electron microscopy, scanning electron microscopy/electron back scatter diffraction, X-ray diffraction and neutron diffraction exhibit a general trend to become larger in this order, although the values obtained by X-ray and neutron diffraction are similar in the present steel because austenite is relatively stable. The austenite volume fractions determined by diffraction methods have been found to be affected by the measuring specimen direction, i.e., texture, even by applying the conventional correcting procedure. To avoid this influence, it is recommended to measure both of volume fraction and texture simultaneously using neutron diffraction. Although synchrotron X-ray shows higher angle resolution, its small incident beam size brings poor statistic reliability. The influence of texture cannot be avoided for transmission Bragg edge measurement, either, which must be overcome to realize 2D or 3D volume fraction mapping.

論文

Work hardening, dislocation structure, and load partitioning in lath-martensite determined by ${it in situ}$ neutron diffraction line profile analysis

Harjo, S.; 川崎 卓郎; 友田 陽*; Gong, W.*; 相澤 一也; Tichy, G.*; Shi, Z.*; Ungar, T.*

Metallurgical and Materials Transactions A, 48(9), p.4080 - 4092, 2017/09

AA2017-0020.pdf:3.33MB

${it in situ}$ neutron diffraction during tensile deformation of lath martensite steel containing 0.22 mass% of carbon, is performed using TAKUMI of J-PARC. The diffraction peaks at plastically deformed states exhibit asymmetries as the reflection of redistributions of the stress and dislocation densities/arrangements in lath-packets where the dislocation glides are favorable (soft packet) and unfavorable (hard packet). The dislocation density is as high as 10$$^{15}$$ m$$^{-2}$$ at the as-quenched state, and then during tensile straining, the load and the dislocation density become different between the two lath-packets. The dislocation character and arrangement vary also in the hard packet, but hardly change in the soft packet. The hard packet plays an important role in the high work hardening in martensite, which could be understood by taking into account not only the increase of the dislocation density but also the change in dislocation arrangement.

論文

Unusual plastic deformation behavior in lath martensitic steel containing high dislocation density

Harjo, S.; 川崎 卓郎; 友田 陽*; Gong, W.

Materials Science Forum, 905, p.46 - 51, 2017/08

To understand the strengthening mechanism of a metallic material with high dislocation density, the plastic deformation behavior of lath martensite was studied by means of in situ neutron diffraction measurements during tensile deformations using a 22SiMn2TiB steel and a Fe-18Ni alloy. The characteristics of dislocation were analyzed and were discussed with the relation of stress-strain curves. The dislocation densities induced by martensitic transformation during heat-treatment in both materials were found to be originally as high as 10$$^{15}$$ m$$^{-2}$$ order, and subsequently to increase slightly by the tensile deformation. The parameter M value which displays the dislocation arrangement dropped drastically at the beginning of plastic deformation in both materials, indicating that the random arrangement became more like a dipole arrangement.

論文

Quantitative evaluation of texture and dislocations during annealing after hot deformation in austenitic steel using neutron diffraction

友田 陽*; 佐藤 成男*; Uchida, M.*; 徐 平光; Harjo, S.; Gong, W.; 川崎 卓郎

Materials Science Forum, 905, p.25 - 30, 2017/08

Microstructural change during hot compressive deformation at 700 $$^{circ}$$C followed by isothermal annealing for a Fe-32Ni austnitic alloy was monitored using ${it in situ}$ neutron diffraction. The evolution of deformation texture with 40% compression and its change to recrystallization texture during isothermal annealing were presented by inverse pole figures for the axial and radial directions. The change in dislocation density was tracked using the convolutional muli-profile whole profile fitting method. To obtain the fitting results with good statistics, at least 60 s time-slicing for the event-mode recorded data was needed. The average dislocation density in 60 s after hot compression was determined to be 2.8 $$times$$ 10$$^{14}$$ m$$^{-2}$$ that decreased with increasing of annealing time.

論文

Time-of-flight neutron transmission imaging of martensite transformation in bent plates of a Fe-25Ni-0.4C alloy

Su, Y.; 及川 健一; 篠原 武尚; 甲斐 哲也; 廣井 孝介; Harjo, S.; 川崎 卓郎; Gong, W.; Zhang, S. Y.*; Parker, J. D.*; et al.

Physics Procedia, 88, p.42 - 49, 2017/06

 被引用回数:1 パーセンタイル:14.69

The influences of bending deformation and subsequent subzero treatment on the martensite transformation behaviors in a metastable austenitic alloy Fe-25Ni-0.4C were investigated by the time-of-flight (TOF) neutron Bragg-edge transmission (BET) imaging method. Two-dimensional (2D) maps of martensite phase volume fractions and texture variations due to residual stress and lowering the temperature of the bent samples before and after subzero treatment were obtained by Bragg-edge spectral analysis. The obtained phase volume fractions were quantitatively compared with those determined by neutron diffraction.

論文

In-situ residual stress analysis during thermal cycle of a dissimilar weld joint using neutron diffraction and IEFEM

秋田 貢一; 柴原 正和*; 生島 一樹*; 西川 聡*; 古川 敬*; 鈴木 裕士; Harjo, S.; 川崎 卓郎; Vladimir, L.*

溶接学会論文集(インターネット), 35(2), p.112s - 116s, 2017/06

Residual stresses near the weld metal of the joints before and after a thermal cycle were measured using a reactor based neutron diffraction technique in room temperature. In-situ residual stress measurements were performed on the plate type sample using a pulsed neutron diffraction technique under thermal cycles. Residual stress behaviors of the samples were examined also by the idealized explicit FEM (IEFEM), which agreed well with the experimental results of the residual stress behaviors during thermal cycles. Thermal stresses were induced near the weld metal by the difference of the linear expansion coefficients of the dissimilar base metals. Since the thermal stress exceeded the yield stress of the material during the first heating process, the residual stresses near the weld metal were redistributed and a part of the residual stress was relaxed.

論文

Composite behavior of lath martensite steels induced by plastic strain, a new paradigm for the elastic-plastic response of martensitic steels

Ung$'a$r, T.*; Harjo, S.; 川崎 卓郎; 友田 陽*; Rib$'a$rik, G.*; Shi, Z.*

Metallurgical and Materials Transactions A, 48(1), p.159 - 167, 2017/01

AA2016-0372.pdf:2.81MB

 被引用回数:7 パーセンタイル:26.53(Materials Science, Multidisciplinary)

Based on high-resolution neutron diffraction experiments we will show that in lath martensite steels the initially homogeneous dislocation structure is disrupted by plastic deformation, to produce a composite on the length scale of martensite lath packets. The diffraction patterns of plastically strained martensitic steel reveal characteristically asymmetric peak profiles in the same way as has been observed in materials with heterogeneous dislocation structures. Lath packets oriented favorably or unfavorably for dislocation glide become soft or hard. The lath packet type develops by work softening or work hardening in which the dislocation density becomes smaller or larger compared to the initial average one. The decomposition into soft and hard lath packets is accompanied by load redistribution between the two lath packet types. The composite behavior of plastically deformed lath martensite opens a new way to understand the elastic-plastic response in this class of materials.

論文

A Comparative study of the crystallite size and the dislocation density of bent steel plates using Bragg-edge transmission imaging, TOF neutron diffraction and EBSD

及川 健一; Su, Y.; 友田 陽*; 川崎 卓郎; 篠原 武尚; 甲斐 哲也; 廣井 孝介; Zhang, S.*; Parker, J. D.*; 佐藤 博隆*; et al.

Physics Procedia, 88, p.34 - 41, 2017/00

 被引用回数:1 パーセンタイル:14.69

TOFブラッグエッジ透過イメージング法を用い、塑性変形させた曲げ鉄鋼試料の微細構造を解析し、得られた結果を中性子回折法及びEBSD法により比較検証を行った。その結果、テキスチャ等は非常に良い一致を示したが、結晶子サイズを中性子回折法による消衰効果から見積もることはうまく行かなかった。そこで、回折プロファイルのブロードニング幅解析から結晶子サイズを求めることを試み、またEBSD法から結晶歪みの解析結果も合わせて再検討を行った。

論文

Magnetic structure of divalent europium compound EuGa$$_{4}$$ studied by single-crystal time-of-flight neutron diffraction

川崎 卓郎; 金子 耕士; 仲村 愛*; 阿曽 尚文*; 辺土 正人*; 仲間 隆男*; 大原 高志; 鬼柳 亮嗣; 及川 健一; 田村 格良; et al.

Journal of the Physical Society of Japan, 85(11), p.114711_1 - 114711_5, 2016/11

 パーセンタイル:100(Physics, Multidisciplinary)

The magnetic structure of the intermetallic compound EuGa$$_{4}$$ was investigated using single-crystal neutron diffraction with TOF Laue technique on the new diffractometer SENJU at MLF of J-PARC. Despite of the high neutron absorption of Eu, a vast number of diffraction spots were observed without isotope enrichment. The magnetic reflections appeared at $$h + k + l$$ $$neq$$ 2$$n$$ below 16 K, indicating that the ordering vector is $$q$$ = (0, 0, 0). The continuous evolution of the magnetic reflection intensity below T$$_{N}$$ follows a squared Brillouin function for $$S$$ = 7/2. By adopting a wavelength-dependent absorption collection, the magnetic structure of EuGa$$_{4}$$ revealed that a nearly full magnetic moment of 6.4 $$mu$$B of Eu lies within the basal plane of the lattice.

論文

Line profile analyses of a martensitic steel during continuous and stepwise tensile deformations

川崎 卓郎; Harjo, S.; Gong, W.; 相澤 一也

Journal of Physics; Conference Series, 746(1), p.012044_1 - 012044_6, 2016/10

The microstructure of the metallic material is widely investigated in order to understand mechanical properties of the material by line profile analysis for X-ray and neutron diffraction data. Neutron diffraction has an advantage for obtaining averaged information of the microstructure inside the bulky material owing to its high transmittance. Further, the variation of the microstructure in the material during mechanical process is able to be observed by in-situ measurements. The Convolutional Multiple Whole Profile (CMWP) fitting method is a state of the art technique for line profile analysis. The dislocation characteristics are evaluated from the shape of the peak profile including the tail by this technique. In this study, the dislocation characteristics in martensitic steels during tensile deformation were studied by in-situ neutron diffraction measurement using the Engineering Materials Diffractometer TAKUMI at J-PARC through line profile analysis using the CMWP fitting method.

129 件中 1件目~20件目を表示