記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：公益社団法人 日本金属学会  

In Al-Zn-Mg alloy, hydrogen (H) leads remarkably to the degradation of mechanical properties. It is indispensable to suppress this phenomenon called hydrogen embrittlement (HE) for developing the high-strength Al-Zn-Mg alloy. Because intergranular fracture (IGF) is mainly observed when HE occurs in the alloy, we need to understand the initiation behavior of IGF in order to suppress HE. Heterogeneous distribution of stress, strain and H concentration usually influence the IGF initiation in polycrystalline material. In the present study, we investigated distribution of stress, strain, and H concentration in actual fractured regions by simulation employing a crystal plasticity finite element method and H diffusion analysis in a 3D image-based model, which was created based on 3D polycrystalline microstructure data obtained from X-ray imaging technique. Combining the simulation and in-situ observation of the tensile test sample by X-ray CT, we examined the distribution of stress, strain, and H concentration in actual crack initiation behavior. Based on this, the condition for intergranular crack initiation were discussed. As a result, it is revealed that stress normal to grain boundary induced by crystal plasticity dominates intergranular crack initiation. In contrast, accumulation of internal H due to the stress has little impact on crack initiation.

DOI： 10.2320/matertrans.mt-l2024007

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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：公益社団法人 日本金属学会  

Recent research has shown that some intermetallic compound particles with high interfacial hydrogen trap energies (e.g., Mg2Si) are prone to damage at high hydrogen concentrations. In this study, the acceleration of particle damage in an A6061 alloy was observed in-situ via X-ray CT. The damage behavior of the particles that are located in the crack tip stress field, where high stress triaxiality causes a local increase in the hydrogen concentration, was analyzed. The influence of hydrogen on the damage behavior of the dispersed Mg2Si particles was investigated by preparing a material charged with hydrogen to achieve extremely high hydrogen concentration, and further hydrogen enrichment in a crack tip region was also utilized. Interfacial debonding of Mg2Si particles was frequently observed in the vicinity of a crack tip immediately prior to tensile fracture. Even though the fracture is typical of ductile fracture, hydrogen accelerates particle damage and reduces the macroscopic ductility of the aluminum alloy. This can be considered as a form of hydrogen embrittlement of aluminum alloys. Even in materials with relatively low hydrogen concentrations (0.85 mass ppm), interfacial debonding occurred in the hydrogen-enriched crack tip regions. A higher hydrogen concentration promoted interfacial debonding over a wider range of particle sizes and particle shapes. It can be inferred that localized hydrogen enrichment, which is expected to occur due to external hydrogen exposure, stress corrosion cracking, corrosion or crack tips, can directly contribute to debonding at the Mg2Si particle/aluminum matrix interface. According to the analysis, reduction of the diameter and simplification of the shape of Mg2Si particles are effective method for suppressing such hydrogen-induced debonding.

DOI： 10.2320/matertrans.mt-m2024026

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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：Computational Materials Science  

Surrogate-based microstructural optimization was applied to describe the relationship between local microstructural patterns and particle damage in wrought 2024 aluminium alloy. A support vector machine was used to realise high-accuracy optimisation from a limited number of high-computational-cost image-based simulation results. The methodology integrated thoroughgoing microstructural quantification, a couple of coarsening processes, and surrogate modelling. The following three objective functions were defined: the maximum principal stress in particles, the equivalent plastic strain, and the stress triaxiality in the matrix. A number of design parameters were comprehensively prepared that quantitatively expressed the size, shape, and spatial distribution of particles and pre-existing micro pores in numerous ways. The number of design parameters was then reduced from 86 to 4 for each objective function during the coarsening process. The surrogate model provided the dependency of particle damage for the size, shape, and spatial distribution of particles and micro pores in the form of a multi-dimensional response surface. It has been established that micro void formation can be described using the simple volume and surface area of particles through the elevation of particle stress and the increase in equivalent plastic strain in the matrix, and the spatial distribution of pre-existing micro pores is of crucial importance for micro void growth through the elevation of stress triaxiality in the matrix. The proposed material microstructure optimisation method provides relationships between complex local microstructural patterns and material properties that are not available from existing material development approaches. It is a computationally inexpensive and reasonable method that can optimise the complex and irregular microstructures of real materials with high efficiency and accuracy.

DOI： 10.1016/j.commatsci.2024.113115

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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  

In order to observe type IV fracture occurring in the HAZ fine-grained zone of a modified 9Cr–1Mo steel at high resolution, the creep damage process of a single notched specimen was continuously observed in three dimensions. The initiation, growth and coalescence behaviour of individual creep voids were clearly observed. This was combined with an analysis of the local stress state using the finite element method. Furthermore, all creep voids that could be observed in the final loading stage were traced backward in time to determine the loading stages at which the creep voids were initiated together with the growth behaviour of the individual creep voids. Significant creep void formation was observed a little further in from the bottom of the notch, where the maximum principal and hydrostatic stresses were greatest, while the stress triaxiality was greatest a little closer to the centre of the specimen than the maximum principal and hydrostatic stresses, where significant creep void growth was observed. It was found that the creep voids nucleated at an early loading stage dominated the creep failure of the specimen. The growth behaviour could be well approximated by the model that combined the diffusion law and power creep law with the constraint effect from neighbouring grains. Engineering parameters that describe the progress of type IV damage were also investigated.

DOI： 10.1016/j.msea.2024.146607

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掲載種別：研究論文（学術雑誌）   出版者・発行元：International Journal of Hydrogen Energy  

Hydrogen embrittlement (HE) suppression by doping an aluminum–zinc–magnesium (Al–Zn–Mg) alloy with tin (Sn) is reported experimentally. The suppression likely results from hydrogen absorption by Sn second-phase particles. We verified the suppression effect of the Sn second-phase particle absorbing hydrogen through numerical simulation using a model based on the reaction–diffusion equation incorporating the solid solution energy of hydrogen, which is evaluated by the first-principles calculation. Consequently, it was found that if the concentration of hydrogen solid solution sites in the Sn second-phase particle is five times higher than that of the Al phase, hydrogen absorption by the Sn second-phase particles is effective for suppressing HE. Therefore, in practice, the effect of Sn second-phase particle on HE suppression was limited.

DOI： 10.1016/j.ijhydene.2024.05.146

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：公益社団法人 日本金属学会  

The surrogate–based microstructural optimization was applied to describe the relationship between local crystallographic microstructure and intergranular hydrogen embrittlement in an Al–Zn–Mg alloy. The support vector machine with an infill sampling criterion was used to realise high–accuracy optimisation with a limited size of data set. The methodology integrates thoroughgoing microstructural quantification, a couple of coarsening processes and the surrogate modelling. An objective function was defined together with 66 design parameters, which quantitatively express the size, shape, orientation and damage during specimen machining for surface grain boundaries and grains. The number of design parameters was then reduced from 66 to 3 during the two–step coarsening process. It has been clarified that intergranular crack initiation is described using the simple size of grains and grain boundaries together with grain boundary orientation with respect to the loading direction. It can be inferred that those design parameters are of crucial importance for crack initiation through the elevation in stress normal to grain boundaries. Correlation between the selected design parameters and crack initiation was rather weak compared to the past application of a similar technique to particle damage. The reason for this was discussed. The present approach offers a cost–efficient solution for the prevention of hydrogen embrittlement through 3D design of crystallographic microstructure, which cannot be obtained with the conventional approaches for developing materials.

DOI： 10.2320/jinstmet.j2023028

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記述言語：その他   掲載種別：研究論文（学術雑誌）   出版者・発行元：Materials Transactions  

An increase in the volume fraction of pores in aluminum alloys causes a decrease in the elongation and the strength of alloys. To improve the mechanical properties of aluminum alloys, it is important to understand the growth and shrinkage behavior of pores. In this study, we analyzed the relationship between hydrogen desorption behavior and the growth/shrinking behavior of pores in A6061 alloys and pure aluminum using thermal desorption analysis and synchrotron radiation X-ray tomography. In pure aluminum, the fine pores began to annihilate at temperatures above 500°C and the relatively large pores coarsened. In contrast, the pores shrank with increasing temperature in A6061 alloy. The influence of second-phase particles has been discussed as a possible explanation for the difference in the nature of pores at elevated temperatures in pure aluminum and A6061 alloys. As in the A6061 alloy, much of the hydrogen desorbed from the pores due to heating is released externally from the second-phase particles on the aluminum surface, resulting in pore shrinkage due to the internal pressure drop of pores.

DOI： 10.2320/matertrans.mt-l2023017

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

Stress corrosion cracking (SCC) behaviors induced by the combination of external and internal hydrogen (H) in an Al-Zn-Mg-Cu alloy were systematically investigated via in-situ 3D characterization techniques. SCC of the Al-Zn-Mg-Cu alloy could initiate and propagate in the potential crack region where the H concentration exceeded a critical value, in which the nanoscopic H-induced decohesion of η-MgZn2 precipitates resulted in macroscopic cracking. External H that penetrated the alloy from the environment played a crucial role during the SCC of the Al-Zn-Mg-Cu alloy by generating gradient-distributed H-affected zones near the crack tips, which made Al alloys in water environment more sensitive to SCC. Additionally, the pre-existing internal H was driven toward the crack tips during plastic deformation. It was involved in the SCC and made contributions to both the cracks initiation and propagation.

DOI： 10.1016/j.scriptamat.2023.115804

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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：公益社団法人 日本金属学会  

Surrogate-based microstructural optimization was applied to model the relationship between local crystallographic microstructure and intergranular hydrogen embrittlement in an Al–Zn–Mg alloy, and a support vector machine with an infill sampling criterion was used to realise high-accuracy optimisation with a limited data set. This methodology integrates thoroughgoing microstructural quantification, two coarsening processes, and surrogate modelling. An objective function was defined together with 66 design parameters that quantitatively express size, shape, orientation and damage during specimen machining for surface grain boundaries and grains. The number of design parameters was then reduced from 66 to 3 during the two-step coarsening process. It has been clarified that intergranular crack initiation can be described using the simple size of grains and grain boundaries together with grain boundary orientation with respect to the loading direction. It can be inferred that these design parameters are of crucial importance in crack initiation through elevation in stress normal to grain boundaries. Correlation between the selected design parameters and crack initiation was somewhat weak compared to past applications of a similar technique to particle damage. The reason for this is discussed. The present approach offers a cost-efficient solution for the prevention of hydrogen embrittlement through 3D design of crystallographic microstructure that cannot be obtained using conventional strategies for developing materials.

DOI： 10.2320/matertrans.MT-M2023116

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記述言語：日本語   出版者・発行元：一般社団法人 軽金属学会  

In Al-Zn-Mg alloy, hydrogen leads to degradation of mechanical properties. It is indispensable to suppress this phenomenon called hydrogen embrittlement (HE) for increasing the strength of Al-Zn-Mg alloy. Intergranular fracture (IGF) mainly occurs when HE affects this alloy. In order to suppress HE, we need to understand the initiation behavior of IGF. Heterogeneous distribution of stress, strain and hydrogen concentration in polycrystalline material have an influence on the IGF initiation. In the present study, distribution of stress, strain and hydrogen concentration in actual fractured regions were investigated by employing a crystal plasticity finite element method and hydrogen diffusion analysis using a 3D-image-based model. This model was created based on 3D polycrystalline microstructure data obtained from X-ray imaging technique. By combining in-situ observation of tensile test of the same sample by X-ray CT with the simulation, we compared distribution of stress, strain and hydrogen concentration with actual crack initiation behavior. Based on this, the condition for intergranular crack initiation were discussed. As a result, it is revealed that stress load perpendicular to grain boundary induced by crystal plasticity dominate intergranular crack initiation. In addition, accumulation of internal hydrogen induced by crystal plasticity had little impact on crack initiation.

DOI： 10.2464/jilm.73.530

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

This paper proposes a methodology for surrogate-based microstructural optimization of structural metals that integrates a limited number of 3D image-based numerical simulations with microstructural quantification, coarsening and optimisation processes. The support vector machine that was used had an infill sampling criterion to reduce the number of numerical trials, and the proposed methodology was found to be effective for wrought 2024 aluminium alloy with irregularly shaped particles. Appropriate objective functions were defined to assess particle damage. The number of design parameters, which quantitatively express the size, shape, and spatial distribution of particles, was initially 41, but they were reduced to four during a two-step coarsening process. The surrogate model provided highly accurate predictions, and the size, shape, and spatial distribution values of the optimal and weakest particles were successfully identified. It was shown that the optimal particle was small, spherical, sparsely dispersed, and perpendicular to the loading direction. However, it was also found that the smallest and most independent particle with a spherical shape was not necessarily strong, which implies the effects of particle clustering. It was also concluded that the dependency of in-situ particle strength on size was of crucial importance for weaker particles. The shape and spatial distribution of stronger particles were, however, more crucial for suppressing their internal stress than was their size. The results show that the proposed methodology offers a cost-efficient solution for microstructural designs involving 3D high-fidelity simulations that cannot be obtained with the existing approaches for developing materials.

DOI： 10.1016/j.actamat.2023.119188

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：一般社団法人 軽金属学会  

An increase in the volume fraction of pores in aluminum alloys causes a decrease in the elongation and the strength of alloys. To improve the mechanical properties of aluminum alloys, it is important to understand the growth and shrinkage behavior of pores. In this study, we analyzed the relationship between hydrogen desorption behavior and the growth/shrinking behavior of pores in A6061 alloys and pure aluminum using thermal desorption analysis and synchrotron radiation X-ray tomography. In pure aluminum, the fine pores began to annihilate at temperatures above 500°C and the relatively large pores coarsened. In contrast, the pores shrank with increasing temperature in A6061 alloy. The influence of second-phase particles has been discussed as a possible explanation for the difference in the nature of pores at elevated temperatures in pure aluminum and A6061 alloys. As in the A6061 alloy, much of the hydrogen desorbed from the pores due to heating is released externally from the second-phase particles on the aluminum surface, resulting in pore shrinkage due to the internal pressure drop of pores.

DOI： 10.2464/jilm.73.212

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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：Corrosion  

<jats:p>7xxx aluminum alloys are representative high-strength aluminum alloys; however, mechanical property degradation due to hydrogen hinders further strengthening. We have previously reported that hydrogen embrittlement in 7xxx alloys originates from trapped hydrogen at the MgZn2 precipitate interface, providing high hydrogen trapping energy. We propose the dispersion of Mn-based second-phase particles as a novel technique for preventing 7xxx aluminum alloy hydrogen embrittlement. In this study, the deformation and fracture behaviors of high hydrogen 7xxx alloys containing 0.0% Mn and 0.6% Mn are observed in situ using synchrotron radiation X-ray tomography. Although no significant differences appear between the two alloys regarding the initiation of quasicleavage cracks, the area fractions of final quasicleavage fractures are 16.5% and 1.0% for 0.0%Mn and 0.6%Mn alloys, respectively; this finding indicates that the Mn addition reduces hydrogen-induced fractures. The obtained macroscopic hydrogen embrittlement is quantitatively analyzed based on hydrogen partitioning in alloys. Adding 0.6% Mn, generating second-phase particles with high hydrogen trapping abilities, significantly suppresses hydrogen-induced quasicleavage fracture. The results of an original hydrogen partitioning analysis show that the dispersion of Mn-based particles (Al12Mn3Si) with high hydrogen trapping abilities reduces the hydrogen concentration at the semicoherent MgZn2 interface and suppresses hydrogen embrittlement.</jats:p>

DOI： 10.5006/4300

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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：International Journal of Fatigue  

Local 3D short fatigue crack closure behavior was investigated in Ti-6Al-4V alloy using ultra-high-resolution X-ray microtomography (XMT). The results show that the inhomogeneous distribution of plasticity-induced and roughness-induced crack closure is caused by the variation of crack path morphologies. These crack path morphologies exhibited heterogeneous plastic deformation at the crack-tips due to the anisotropic nature of α grains and varying extents of crack tilting and twisting caused by the interaction of the crack front with α/α boundary or α/α + β interface. It was revealed via surrogate-based statistical analysis that the Schmid factor has the strongest effect on crack growth rate.

DOI： 10.1016/j.ijfatigue.2022.107428

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記述言語：その他   掲載種別：研究論文（学術雑誌）   出版者・発行元：Nature Publishing Group  

Hydrogen drastically embrittles high-strength aluminum alloys, which impedes efforts to develop ultrastrong components in the aerospace and transportation industries. Understanding and utilizing the interaction of hydrogen with core strengthening elements in aluminum alloys, particularly nanoprecipitates, are critical to break this bottleneck. Herein, we show that hydrogen embrittlement of aluminum alloys can be largely suppressed by switching nanoprecipitates from the η phase to the T phase without changing the overall chemical composition. The T phase strongly traps hydrogen and resists hydrogen-assisted crack growth, with a more than 60% reduction in the areal fractions of cracks. The T phase-induced reduction in the concentration of hydrogen at defects and interfaces, which facilitates crack growth, primarily contributes to the suppressed hydrogen embrittlement. Transforming precipitates into strong hydrogen traps is proven to be a potential mitigation strategy for hydrogen embrittlement in aluminum alloys.

DOI： 10.1038/s41467-022-34628-4

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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：公益社団法人 日本金属学会  

Recent studies have revealed that hydrogen embrittlement in Al-Zn-Mg alloys appears to be dominated by hydrogen partitioning to MgZn2 precipitates. A method has recently been proposed for reducing the hydrogen concentration at MgZn2 precipitates by adding specific intermetallic compound particles that have high hydrogen trap energy. In the present study, the effectiveness of Al7Cu2Fe particles on suppression of hydrogen embrittlement in Al-Zn-Mg-Cu alloys was evaluated using X-ray microtomography. Quasi-cleavage cracks were found to be initiated in regions where local volume fractions of the Al7Cu2Fe particles were relatively low. Hydrogen partitioning to the MgZn2 precipitate interface was suppressed, even in high hydrogen concentration material, by adding Al7Cu2Fe particles. However, the fractional area of the quasi-cleavage fracture in the material with high hydrogen concentration was higher due to insufficient hydrogen diffusion inside the Al7Cu2Fe particles and at the interface between the aluminum matrix and the particles. It appears that finely distributed small Al7Cu2Fe particles might effectively suppress hydrogen embrittlement.

DOI： 10.2320/matertrans.mt-l2022007

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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 Transactions  

In recent years, it has been reported that intermetallic compound particles can suppress hydrogen embrittlement by hydrogen trapping. Some intermetallic particles in aluminum alloys, such as Al7Cu2Fe, have internal hydrogen trap sites; it is proposed that hydrogen embrittlement can be suppressed by preferential hydrogen partitioning in these sites. However, intermetallic compound particles act as fracture origin sites, and excessive addition degrades the mechanical properties of the material. In this study, we quantitatively evaluated the damage and decohesion behavior of intermetallic compound particles in high-hydrogen content 7XXX aluminum alloys by using in situ synchrotron radiation X-ray tomography. The results revealed that the hydrogen particles induced early high-strain localization, and the Al7Cu2Fe particles were damaged in that region due to its brittleness, resulting in early fracture. Hydrogen had no effects on the fracture and debonding behaviors of intermetallic compound particles, suggesting that the observed particle brittle fracture is dependent on their mechanical properties.

DOI： 10.2320/matertrans.mt-l2022020

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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：Acta Materialia  

The pursuit of strong and ductile Al alloys with superior resistance to hydrogen embrittlement (HE) is practically significant across the aerospace and transportation industries among others. Unfortunately, effective ways to progress on the strength-HE trade-off for Al-alloys remain elusive. A strategy of suppressing HE by introducing intermetallic compound (IMC) particles to achieve hydrogen redistribution in various trapping sites was proposed. Here, we systematically induce the precipitation of a constant volume fraction of intermetallic compound (IMC) particles by adding one of 14 elements in a ternary Al-Zn-Mg high-strength alloy. We show a strong correlation between hydrogen trapping energies of the IMC obtained from ab initio calculations with the resistance to HE. Mn-rich Al11Mn3Zn2 particles exhibit the highest hydrogen trapping energy (0.859 eV/atom), leading to a decrease by approximately 5 orders of magnitude in the hydrogen occupancy in eta(2) (MgZn2) phase interfaces and grain boundaries, where HE cracks initiate. The Mn-addition did not deteriorate the ductility and most Al11Mn3Zn2 particles remained intact during plastic deformation which was revealed by in-situ 3D X-ray tomography. Hydrogen-induced strain localization at eta(2) phase interfaces and grain boundaries were inhibited due to strong hydrogen trapping capacity of Al11Mn3Zn2, hence preventing HE cracks initiation. Our approach effectively suppresses hydrogen-induced cracks without sacrificing the ductility, and our strategy can help the design roadmap of HE-tolerant high-strength metallic alloys. (C) 2022 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.actamat.2022.118110

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記述言語：その他   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

A combination of X-ray nano-tomography and pencil-beam diffraction tomography was utilized for multimodal assessment of the mechanically induced transformation of individual retained austenite grains during tensile deformation in a 0.1C-5Mn-1Si multi-phase steel. In the present study, a newly developed high energy (20 - 30 keV) and high resolution (spatial resolution of 0.16 µm in this study) X-ray nano-tomography technique was applied for the first time to the in-situ observation of a steel under external loading. The gradual transformation, plastic deformation, and rotation behaviour of the individual austenite grains were clearly observed in 3D. It was revealed that the early stage of the transformation was dominated by the stress-assisted transformation that can be associated with measured mechanical driving force, whilst the overall transformation was dominated by the strain-induced transformation that is interrelated with measured dislocation multiplication. The transformation behaviour of individual grains was classified according to their initial crystallographic orientation and size. Noteworthy was the high stability of coarse austenite grains (i.e., 2.5 μm or larger in diameter), contrary to past reports in the literature. Characteristic rotation behaviour and wide data dispersion were also observed in the case of the individual austenite grains. It was conclusively demonstrated that such characteristic behaviour partly originated from interactions with surrounding soft and hard phases. The origins of these characteristics are discussed by combining the image-based and diffraction-based information.

DOI： 10.1016/j.actamat.2022.117956

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：一般社団法人 軽金属学会  

In recent years, it has been reported that intermetallic compound particles can suppress hydrogen embrittlement by hydrogen trapping into them. Some intermetallic particles in aluminum alloys, such as Al7Cu2Fe, have internal hydrogen trap sites and it is proposed that hydrogen embrittlement can be suppressed by preferential hydrogen partitioning to these sites. However, intermetallic compound particles act as fracture origin, and excessive addition degrades the mechanical properties. In this study, we quantitatively evaluated the damage and decohesion behavior of intermetallic compound particles in high-hydrogen 7XXX aluminum alloys by using in-situ synchrotron radiation X-ray tomography. As the results, it has been revealed that hydrogen induced early high-strain localization, and the Al7Cu2Fe particles were damaged in that region due to own brittleness, resulting in early fracture. Hydrogen had no effect on the fracture and debonding behavior of intermetallic compound particles, suggesting that observed brittle fracture of particles is dependent on the mechanical properties of the particles.

DOI： 10.2464/jilm.72.411

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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：Elsevier  

We directly captured, classified, and evaluated 3D particle debonding and fracture behavior in a H-charged 7075 Al alloy throughout the entire tensile deformation using synchrotron X-ray tomography and microstructural feature tracking techniques. The effects of particle size, shape, spatial clustering and stress state on strain-dependent particle damage were identified and isolated from each other. Moreover, state-of-the-art imaging and tracking techniques enabled the establishment of spatially and time-resolved hydrogen distributions during deformation. Based on realistic hydrogen partitioning among various nanoscopic trap sites, the contributions of particles to hydrogen trapping and the hydrogen effect at individual damaged particles were assessed quantitatively. Fracturing of coarse and irregular Al7Cu2Fe particles was found to be the predominant particle damage mode due to the spatial clustering and brittleness of these particles, but a hydrogen effect was not observed. The debonding of Mg2Si particles seemed to be the result of competition between hydrogen and clustering-induced stress localization, but detrimental effects of hydrogen on ductile fracture induced by accelerating interfacial debonding were found to be limited. The quantitative evaluation of particle damage in the present model material clarified a viable strategy for mitigating hydrogen embrittlement, which involves introducing and modifying intermetallic particles with strong hydrogen trapping capacities.

DOI： 10.1016/j.actamat.2022.117658

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記述言語：英語  

DOI： 10.2320/matertrans.L-M2020873

記述言語：日本語  

Hydrogen in materials degrades mechanical properties, which is widely recognized as hydrogen embrittlement. To understand hydrogen embrittlement, it is necessary to clarify the accumulation behavior of hydrogen under stress. The neutron radiography and neutron tomography techniques are applied to examine whether hydrogen accumulation behavior can be visualized directly. Palladium specimens with and without hydrogen were prepared for the neutron imaging experiment under stress. Solute hydrogen has caused distinct contrast change in both the neutron radiography and neutron tomography. Hydrogen distribution at a notch-tip in a loaded specimen has not been visualized in the tomographic cross-sectional images. It can be inferred that this is fundamentally attributable to low spatial resolution of the present imaging set-up, and possibility to visualize hydrogen distribution due to loading is discussed.

DOI： 10.2320/jinstmet.J2020017

記述言語：英語  

DOI： 10.1016/j.mtla.2020.100667

記述言語：英語  

DOI： 10.1016/j.engfracmech.2019.106503

記述言語：日本語  

DOI： 10.2464/jilm.69.186

記述言語：英語   掲載種別：研究論文（その他学術会議資料等）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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開催年月日： 2023年12月

記述言語：英語   会議種別：口頭発表（招待・特別）  

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開催年月日： 2023年12月

記述言語：英語  

国名：その他  

開催年月日： 2023年12月

記述言語：英語   会議種別：口頭発表（一般）  

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開催年月日： 2023年12月

記述言語：英語   会議種別：口頭発表（一般）  

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開催年月日： 2023年12月

記述言語：英語   会議種別：口頭発表（一般）  

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開催年月日： 2023年12月

記述言語：英語   会議種別：口頭発表（一般）  

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開催年月日： 2023年11月

記述言語：日本語  

国名：その他  

開催年月日： 2023年11月

記述言語：日本語  

国名：その他  

開催年月日： 2023年11月

記述言語：日本語   会議種別：口頭発表（一般）  

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開催年月日： 2023年11月

記述言語：日本語   会議種別：ポスター発表  

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開催年月日： 2023年11月

記述言語：日本語   会議種別：口頭発表（一般）  

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開催年月日： 2023年10月

記述言語：英語  

国名：その他  

開催年月日： 2023年10月

記述言語：英語   会議種別：口頭発表（一般）  

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開催年月日： 2023年10月

記述言語：英語   会議種別：口頭発表（一般）  

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開催年月日： 2023年10月

記述言語：英語   会議種別：口頭発表（一般）  

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開催年月日： 2023年10月

記述言語：英語   会議種別：口頭発表（一般）  

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開催年月日： 2023年10月

記述言語：英語   会議種別：口頭発表（一般）  

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開催年月日： 2023年9月

記述言語：日本語  

国名：その他  

開催年月日： 2023年9月

記述言語：日本語   会議種別：口頭発表（一般）  

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開催年月日： 2023年9月

記述言語：日本語   会議種別：口頭発表（一般）  

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開催年月日： 2023年9月

記述言語：日本語   会議種別：口頭発表（一般）  

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開催年月日： 2023年9月

記述言語：日本語   会議種別：ポスター発表  

国名：日本国  

開催年月日： 2023年9月

記述言語：英語  

国名：その他  

Assessment of hydrogen embrittlement behavior in Al-Zn-Mg alloys by multimodal 3D image-based simulation

開催年月日： 2023年9月

記述言語：英語  

国名：その他  

Role of T phase in the hydrogen embrittlement suppression for Al-Zn-MgCu alloys

開催年月日： 2023年9月

記述言語：英語   会議種別：ポスター発表  

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開催年月日： 2023年8月

記述言語：日本語  

国名：その他  

開催年月日： 2023年5月

記述言語：日本語  

国名：その他  

開催年月日： 2023年5月

記述言語：日本語   会議種別：ポスター発表  

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開催年月日： 2023年3月

記述言語：日本語  

国名：その他  

開催年月日： 2023年3月

記述言語：日本語  

国名：その他  

開催年月日： 2023年3月

記述言語：日本語   会議種別：口頭発表（一般）  

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開催年月日： 2022年11月

記述言語：日本語  

国名：その他  

開催年月日： 2022年11月

記述言語：日本語  

国名：その他  

開催年月日： 2022年11月

記述言語：日本語   会議種別：口頭発表（一般）  

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開催年月日： 2022年10月

記述言語：日本語  

国名：その他  

開催年月日： 2022年10月

記述言語：日本語  

国名：その他  

開催年月日： 2022年9月

記述言語：日本語  

国名：その他  

開催年月日： 2022年9月

記述言語：日本語   会議種別：口頭発表（一般）  

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開催年月日： 2022年9月

記述言語：英語  

国名：その他  

開催年月日： 2022年9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： 2022年9月

記述言語：英語   会議種別：口頭発表（招待・特別）  

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開催年月日： 2022年9月

記述言語：英語   会議種別：口頭発表（一般）  

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開催年月日： 2022年9月

記述言語：英語   会議種別：口頭発表（一般）  

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開催年月日： 2022年9月

記述言語：英語   会議種別：口頭発表（一般）  

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開催年月日： 2022年7月

記述言語：日本語  

国名：その他  

開催年月日： 2022年6月

記述言語：日本語  

国名：その他  

開催年月日： 2022年5月

記述言語：日本語  

国名：その他  

開催年月日： 2022年5月

記述言語：日本語   会議種別：口頭発表（一般）  

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開催年月日： 2022年5月

記述言語：英語   会議種別：口頭発表（一般）  

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開催年月日： 2022年5月

記述言語：日本語   会議種別：口頭発表（一般）  

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開催年月日： 2022年5月

記述言語：日本語   会議種別：口頭発表（一般）  

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開催年月日： 2022年5月

記述言語：日本語   会議種別：ポスター発表  

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開催年月日： 2022年5月

記述言語：日本語   会議種別：ポスター発表  

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開催年月日： 2022年5月

記述言語：日本語  

国名：その他  

開催年月日： 2022年3月

記述言語：日本語  

開催地：オンライン   国名：その他  

開催年月日： 2022年3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  

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開催年月日： 2022年3月

記述言語：日本語  

開催地：オンライン   国名：日本国  

開催年月日： 2022年3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  

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開催年月日： 2021年12月

記述言語：英語   会議種別：口頭発表（一般）  

国名：その他  

開催年月日： 2021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： 2021年11月

記述言語：日本語  

開催地：オンライン   国名：日本国  

開催年月日： 2021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： 2021年6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： 2021年6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： 2021年5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： 2021年5月

記述言語：日本語  

国名：その他  

開催年月日： 2021年5月

記述言語：日本語  

国名：その他  

開催年月日： 2021年5月

記述言語：日本語  

国名：その他  

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  

開催年月日： 2020年5月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：香川大学 幸町キャンパス（中止）   国名：日本国  

開催年月日： 2020年5月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：香川大学 幸町キャンパス（中止）   国名：日本国  

開催年月日： 2019年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：東京農工大学 小金井キャンパス   国名：日本国  

開催年月日： 2019年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：東京農工大学 小金井キャンパス   国名：日本国  

開催年月日： 2019年9月

記述言語：英語   会議種別：口頭発表（一般）  

国名：スウェーデン王国  

開催年月日： 2019年9月

記述言語：英語   会議種別：ポスター発表  

国名：スウェーデン王国  

開催年月日： 2019年7月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：九州工業大学 戸畑キャンパス   国名：日本国  

開催年月日： 2019年6月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：熊本県民交流館パレア   国名：日本国  

開催年月日： 2018年8月

記述言語：英語   会議種別：口頭発表（一般）  

国名：その他  

開催年月日： 2018年6月

記述言語：英語   会議種別：口頭発表（一般）  

国名：カナダ  

開催年月日： 2018年5月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：熊本大学 黒髪南キャンパス   国名：日本国  

開催年月日： 2018年5月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：熊本大学 黒髪南キャンパス   国名：日本国  

開催年月日： 2018年3月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：千葉工業大学 新習志野キャンパス   国名：日本国  

開催年月日： 2017年5月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：名古屋大学 東山キャンパス   国名：日本国  

開催年月日： 2017年3月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：首都大学東京 南大沢キャンパス   国名：日本国  

開催年月日： 2016年10月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：神戸大学 六甲台第二キャンパス   国名：日本国  

開催年月日： 2016年9月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：大阪大学 豊中キャンパス   国名：日本国  

開催年月日： 2016年8月

記述言語：英語   会議種別：ポスター発表  

国名：日本国  

開催年月日： 2016年7月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：㈱神戸製鋼所 長府製造所   国名：日本国  

開催年月日： 2016年6月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：九州大学 筑紫キャンパス   国名：日本国  

開催年月日： 2016年5月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：大阪大学 吹田キャンパス   国名：日本国  

開催年月日： 2016年3月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：東京理科大学 葛飾キャンパス   国名：日本国  

開催年月日： 2015年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：應義塾大学 矢上キャンパス   国名：日本国