{"title":"Enhanced Hardness of Pure Magnesium by MgO Formation Fabricated by Powder Metallurgy","authors":"Takumi Inomiya, M. Kubota","doi":"10.2497/jjspm.70.3","DOIUrl":"https://doi.org/10.2497/jjspm.70.3","url":null,"abstract":"","PeriodicalId":35600,"journal":{"name":"Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47744018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Improvements in Flash Sintering for Practical Application","authors":"Takahisa Yamamoto","doi":"10.2497/jjspm.70.18","DOIUrl":"https://doi.org/10.2497/jjspm.70.18","url":null,"abstract":"","PeriodicalId":35600,"journal":{"name":"Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48356387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Development of Linear-Drive Type Modulated Rotating Magnetic Field Equipment","authors":"S. Horii","doi":"10.2497/jjspm.70.11","DOIUrl":"https://doi.org/10.2497/jjspm.70.11","url":null,"abstract":"","PeriodicalId":35600,"journal":{"name":"Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46055991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A unique deformation microstructure introduced by 20% cold rolling in a Ti-25mass%Nb-25mass%Zr (TNZ) Harmonic Structure (HS) alloy has been studied in detail by crystallographic analysis. The HS consists of soft, coarse-grained regions (Core) that are three-dimensionally surrounded by an interconnected network of hard, ultrafine-grained regions (Shell). The {332}<113> deformation twins are observed in the deformation microstructure of the homogeneous grained TNZ alloy compacts with a sinter holding time of 1.8 ks. In contrast, in the deformation microstructure of the TNZ alloy HS compacts with a sintering holding time of 1.8 ks, deformation bands by slip deformation are observed in Core region. In the deformation microstructure of the TNZ alloy HS compact with a sintering holding time of 0 s, a composite deformation microstructure consisting of two types of deformation bands, {332}<113> deformation twins and <110> axial rotation slip bands, is observed in Core region. It is noteworthy that the same HS material has different deformation structures depending on the sintering time. The reason for the formation of different deformation structures is the effect of the diffusion of Fe elements doped by mechanical milling.
{"title":"Ti-25mass%Nb-25mass%Zr合金調和組織材料の冷間圧延により形成された特異な微細構造","authors":"Kentaro NAGANO, Mie KAWABATA-OTA, Hiroshi FUJIWARA","doi":"10.2497/jjspm.23-00046","DOIUrl":"https://doi.org/10.2497/jjspm.23-00046","url":null,"abstract":"A unique deformation microstructure introduced by 20% cold rolling in a Ti-25mass%Nb-25mass%Zr (TNZ) Harmonic Structure (HS) alloy has been studied in detail by crystallographic analysis. The HS consists of soft, coarse-grained regions (Core) that are three-dimensionally surrounded by an interconnected network of hard, ultrafine-grained regions (Shell). The {332}<113> deformation twins are observed in the deformation microstructure of the homogeneous grained TNZ alloy compacts with a sinter holding time of 1.8 ks. In contrast, in the deformation microstructure of the TNZ alloy HS compacts with a sintering holding time of 1.8 ks, deformation bands by slip deformation are observed in Core region. In the deformation microstructure of the TNZ alloy HS compact with a sintering holding time of 0 s, a composite deformation microstructure consisting of two types of deformation bands, {332}<113> deformation twins and <110> axial rotation slip bands, is observed in Core region. It is noteworthy that the same HS material has different deformation structures depending on the sintering time. The reason for the formation of different deformation structures is the effect of the diffusion of Fe elements doped by mechanical milling.","PeriodicalId":35600,"journal":{"name":"Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135610846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A new synthetic strategy to produce porous ceramic particles with well-defined polyhedral particle morphology and three-dimensionally interconnected mesoporous structure has been developed by means of the combination of topotactic conversion of polyhedral crystal precursors and pyrolysis-induced phase separation. The crystal morphology of precursors is controlled by the liquid-phase synthesis, while the mesoporous structure in each polyhedral particle is tailored by the selective removal of a phase-separated phase preserving the other phase. In this review, two examples of porous polyhedral metal oxides prepared from hydrogarnet precursors: mesoporous and mesocrystalline 12CaO • 7Al2O3 mayenite microcubes and porous SrFeO3-δ perovskite polyhedral particles. The synthesis and characterization of these porous materials as well as their applications in catalysis are overviewed.
{"title":"熱分解に誘起される相分離を利用した多孔質セラミックス多面体粒子の作製","authors":"George HASEGAWA","doi":"10.2497/jjspm.23-00041","DOIUrl":"https://doi.org/10.2497/jjspm.23-00041","url":null,"abstract":"A new synthetic strategy to produce porous ceramic particles with well-defined polyhedral particle morphology and three-dimensionally interconnected mesoporous structure has been developed by means of the combination of topotactic conversion of polyhedral crystal precursors and pyrolysis-induced phase separation. The crystal morphology of precursors is controlled by the liquid-phase synthesis, while the mesoporous structure in each polyhedral particle is tailored by the selective removal of a phase-separated phase preserving the other phase. In this review, two examples of porous polyhedral metal oxides prepared from hydrogarnet precursors: mesoporous and mesocrystalline 12CaO • 7Al2O3 mayenite microcubes and porous SrFeO3-δ perovskite polyhedral particles. The synthesis and characterization of these porous materials as well as their applications in catalysis are overviewed.","PeriodicalId":35600,"journal":{"name":"Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135843479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This symposium includes twelve personal narratives from healthcare professionals who have worked with patients whose behavior, attitudes, or life situations make providing care challenging. At the lower end of the estimates, at least 15% of adult patient encounters are with patients described as "difficult" by the treating team, and these encounters often evoke feelings of dread, frustration, and anger in healthcare professionals. Verbal abuse of staff, repeat hospital admissions due to self-injurious behaviors, and negative beliefs about health may make providing care to this group of patients a daily struggle. Despite these challenges, healthcare providers-especially those who work in an in-patient setting-are obligated to treat all comers, sometimes at the expense of their own mental health. This symposium aims to learn from health professionals' stories the kinds of struggles they face, the lessons they draw from those struggles, and the constructive responses they employ to work successfully with challenging patients.
{"title":"Introduction: Providing Care When Patients Are \"Difficult\".","authors":"Autumn Fiester","doi":"10.1353/nib.2023.0001","DOIUrl":"10.1353/nib.2023.0001","url":null,"abstract":"<p><p>This symposium includes twelve personal narratives from healthcare professionals who have worked with patients whose behavior, attitudes, or life situations make providing care challenging. At the lower end of the estimates, at least 15% of adult patient encounters are with patients described as \"difficult\" by the treating team, and these encounters often evoke feelings of dread, frustration, and anger in healthcare professionals. Verbal abuse of staff, repeat hospital admissions due to self-injurious behaviors, and negative beliefs about health may make providing care to this group of patients a daily struggle. Despite these challenges, healthcare providers-especially those who work in an in-patient setting-are obligated to treat all comers, sometimes at the expense of their own mental health. This symposium aims to learn from health professionals' stories the kinds of struggles they face, the lessons they draw from those struggles, and the constructive responses they employ to work successfully with challenging patients.</p>","PeriodicalId":35600,"journal":{"name":"Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy","volume":"59 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91275176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We developed a neural network-based model to predict the Born effective charges from atomic structures. By combining forces due to an applied electric field, expressed as a product of the Born effective charge and the electric field, and forces evaluated by a neural network potential (NNP), a simulation scheme of ion dynamics under an electric field was proposed. Taking Li3PO4 as a prototype, we demonstrated the validity of our computation scheme. Using the constructed model of the Born effective charge predictor and NNP based on density functional (perturbation) theory calculation data, molecular dynamics (MD) simulations under a uniform electric field of 0.1 V/Å were performed. We obtained an enhanced mean square displacement of Li along the electric field, which seems physically reasonable. In addition, we found that the external forces along the direction perpendicular to the electric field, which originated from the off-diagonal components of the Born effective charges, had a non-negligible effect on the Li motion. Furthermore, we observed a more susceptive response of Li to the electric field in an amorphous structure.
{"title":"Neural Network-Based Simulation Method to Examine Ion Behaviors under Electric Fields: Application to Ion Migration in Amorphous Li<sub>3</sub>PO<sub>4</sub>","authors":"Koji SHIMIZU, Ryuji OTSUKA, Satoshi WATANABE","doi":"10.2497/jjspm.23-00043","DOIUrl":"https://doi.org/10.2497/jjspm.23-00043","url":null,"abstract":"We developed a neural network-based model to predict the Born effective charges from atomic structures. By combining forces due to an applied electric field, expressed as a product of the Born effective charge and the electric field, and forces evaluated by a neural network potential (NNP), a simulation scheme of ion dynamics under an electric field was proposed. Taking Li3PO4 as a prototype, we demonstrated the validity of our computation scheme. Using the constructed model of the Born effective charge predictor and NNP based on density functional (perturbation) theory calculation data, molecular dynamics (MD) simulations under a uniform electric field of 0.1 V/Å were performed. We obtained an enhanced mean square displacement of Li along the electric field, which seems physically reasonable. In addition, we found that the external forces along the direction perpendicular to the electric field, which originated from the off-diagonal components of the Born effective charges, had a non-negligible effect on the Li motion. Furthermore, we observed a more susceptive response of Li to the electric field in an amorphous structure.","PeriodicalId":35600,"journal":{"name":"Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy","volume":"134 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135318565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Usually, expected values for various physical quantities, such as the number of electrons occupying certain states or the Coulomb interaction between different states of electrons, can be expressed in terms of integrals. In contrast, our method, based on differential forms, shows that expected values can be obtained by averaging over time. To confirm the validity of our method, we prepare the two cases: one is a very simple case with no many-body interaction, and the other is the case where the many-body term is included (the simplest Anderson Hamiltonian). Regarding the simple case without inclusion of many-body term, we prove analytically that the number of electrons occupying any state derived from our method is equivalent to the analytical one evaluated from the Greenʼs function method. When the many-body term is included, our results show good numerical agreement with the analytical ones derived from the Greenʼs function method. By the two cases, the calculation of expected values based on our method is considered valid.
{"title":"On the Derivation of Quantum Mechanical Expectations in the Differential Form","authors":"Shin-ichiro KONDO, Tatsushi KONDO, Atsushi KONDO, Kazuyoshi YOSHIMURA","doi":"10.2497/jjspm.23-00042","DOIUrl":"https://doi.org/10.2497/jjspm.23-00042","url":null,"abstract":"Usually, expected values for various physical quantities, such as the number of electrons occupying certain states or the Coulomb interaction between different states of electrons, can be expressed in terms of integrals. In contrast, our method, based on differential forms, shows that expected values can be obtained by averaging over time. To confirm the validity of our method, we prepare the two cases: one is a very simple case with no many-body interaction, and the other is the case where the many-body term is included (the simplest Anderson Hamiltonian). Regarding the simple case without inclusion of many-body term, we prove analytically that the number of electrons occupying any state derived from our method is equivalent to the analytical one evaluated from the Greenʼs function method. When the many-body term is included, our results show good numerical agreement with the analytical ones derived from the Greenʼs function method. By the two cases, the calculation of expected values based on our method is considered valid.","PeriodicalId":35600,"journal":{"name":"Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy","volume":"2014 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135104993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ground round bars made of WC-20 mass%Co cemented carbides were used to accurately determine the changes in shape. The bars were heated at 1673 K and cooled under different conditions to investigate the changes in Co content and diameter (d) in the longitudinal direction. When the bars were heated in a conventional sintering furnace, rapid cooling increased the Co content and d at both ends, while slow cooling increased those at the center. In the latter case, the amount of change was smaller. When the bar was heated using a tubular furnace and then cooled under 30 K of temperature gradient in the longitudinal direction, the Co content and d on the higher temperature side decreased and those on lower temperature side increased. The relationship between the change in Co content and the change in d could be explained quantitatively by considering the migration of the liquid phase in the temperature range of solid-liquid Co coexistence region. This study revealed that when WC-Co cemented carbides were fabricated using the conventional sintering furnace, an inevitable temperature gradient in the specimen during cooing caused the liquid phase migration and the shape distortion, regardless of the cooling rate.
{"title":"Liquid Phase Migration and Shape Distortion in Round Bars of WC-Co Cemented Carbides―The Contribution of Temperature Gradient in Sintered Compacts during Cooling―","authors":"Takeshi SAITO, Hideaki MATSUBARA, Hiroyuki ENDO, Yasuharu FUKUICHI, Taichi KAJIWARA","doi":"10.2497/jjspm.23-00038","DOIUrl":"https://doi.org/10.2497/jjspm.23-00038","url":null,"abstract":"Ground round bars made of WC-20 mass%Co cemented carbides were used to accurately determine the changes in shape. The bars were heated at 1673 K and cooled under different conditions to investigate the changes in Co content and diameter (d) in the longitudinal direction. When the bars were heated in a conventional sintering furnace, rapid cooling increased the Co content and d at both ends, while slow cooling increased those at the center. In the latter case, the amount of change was smaller. When the bar was heated using a tubular furnace and then cooled under 30 K of temperature gradient in the longitudinal direction, the Co content and d on the higher temperature side decreased and those on lower temperature side increased. The relationship between the change in Co content and the change in d could be explained quantitatively by considering the migration of the liquid phase in the temperature range of solid-liquid Co coexistence region. This study revealed that when WC-Co cemented carbides were fabricated using the conventional sintering furnace, an inevitable temperature gradient in the specimen during cooing caused the liquid phase migration and the shape distortion, regardless of the cooling rate.","PeriodicalId":35600,"journal":{"name":"Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy","volume":"45-46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136367491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mitsutaka Sato, Yusuke Shimada, Y. Hishinuma, Naoya Masahashi
{"title":"Fabrication of Oxide Dispersion Strengthened Copper Alloy Powders by Atmosphere-Controlled Gas Atomization","authors":"Mitsutaka Sato, Yusuke Shimada, Y. Hishinuma, Naoya Masahashi","doi":"10.2497/jjspm.23-00017","DOIUrl":"https://doi.org/10.2497/jjspm.23-00017","url":null,"abstract":"","PeriodicalId":35600,"journal":{"name":"Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69150997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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