徳永 辰也 (トクナガ タツヤ)

TOKUNAGA Tatsuya

写真a

職名

准教授

研究室住所

福岡県北九州市戸畑区仙水町1-1

研究分野・キーワード

状態図 相平衡 相変態

メールアドレス

メールアドレス

Scopus 論文情報  
総論文数: 0  総Citation: 0  h-index: 3

Citation Countは当該年に発表した論文の被引用数

出身大学 【 表示 / 非表示

  • 1994年03月   名古屋大学   工学部   原子核工学科   卒業   日本国

出身大学院 【 表示 / 非表示

  • 2004年09月  九州工業大学  工学研究科  物質工学専攻  博士課程・博士後期課程  修了  日本国

  • 1996年03月  名古屋大学  工学研究科  原子核工学専攻  修士課程・博士前期課程  修了  日本国

取得学位 【 表示 / 非表示

  • 九州工業大学 -  博士(工学)  2004年09月

  • 名古屋大学 -  修士(工学)  1996年03月

学内職務経歴 【 表示 / 非表示

  • 2014年04月
    -
    継続中

    九州工業大学   大学院工学研究院   物質工学研究系   准教授  

学外略歴 【 表示 / 非表示

  • 2011年04月
    -
    2014年03月

    鹿児島大学   理工学研究科   准教授   日本国

 

論文 【 表示 / 非表示

  • 溶湯浸透法によるSiC反応焼結体の機械的性質と電気抵抗率に及ぼすFe-Si 合金組成の影響

    花田 喜嗣, 肖 陽, 山本 厚生, 徳永 辰也, 恵良 秀則

    鋳造工学  ( 公益社団法人 日本鋳造工学会 )  92 ( 1 ) 8 - 15   2020年01月  [査読有り]

     概要を見る

    <p>  The authors have been investigating a fabrication method to obtain high performance SiC ceramics by two-step reaction sintering using a Fe-Si alloy that is well known as an inoculation agent. In this study, compositions of C as a constituent of first-sintered body and the Fe-Si alloy as a constituent of molten infiltration alloy for the second sintering were changed for SiC ceramics fabrication. The second-sintered body was fabricated by infiltrating the Fe-Si molten alloy into the porous first-sintered body at 1723 K for 6 h under a pressure lower than 10<sup>-2</sup> Pa. The C content for the first sintered body was changed from 0 to 28 mass%, whereas the Fe concentration of the alloy for infiltration was changed from 0 to 66 mass%. Microstructure observation, elemental distribution measurements of Fe and Si, and phase identification for obtained second-sintered specimens were conducted using a laser microscope, EPMA, and XRD, respectively. Hardness and fracture toughness were evaluated by results of micro Vickers hardness testing. The electrical resistivity was measured using the four-terminal method.</p><p>  The microstructure of sintered SiC changed with the Fe content of the infiltration alloy, whereas the generated amount of SiC changed only slightly irrespective of the Fe content. No Fe carbide formation was observed, but FeSi<sub>2</sub> and FeSi phases were formed at high Fe contents. The fracture toughness of sintered bodies improved to 5.9 MPa·m<sup>0.5</sup> at maximum by the increase in the C content of the first sintered body and the Fe content of the infiltration alloy, although the electrical resistivity was reduced to 1.5 × 10<sup>-5</sup> Ωm at the minimum by the increase in Fe contents. Consequently, the fracture toughness of the Fe-Si alloy infiltrated SiC improved by two times compared to the conventionally sintered SiC ceramics. Furthermore, the electrical resistivity of the SiC sample largely decreased by one digit or more. It is considered that the superior characteristics are brought about by the extensive formation of finely distributed FeSi<sub>2</sub> and FeSi phases.</p>

    DOI CiNii

  • Silicon Carbide Fabrication by Infiltration of Molten Fe-Si Alloy Through Two-Step Reaction Sintering

    Yoshitsugu Hanada, Yang Xiao, Akio Sonoda, Hyo-Gyoung Kang,Hideaki Nagayoshi, Atsuo Yamamoto, Tatsuya Tokunaga

    Archives of Metallurgy and Materials    64 ( 4 ) 1645 - 1652   2019年12月  [査読有り]

    DOI

  • Fe-75%Si 合金を用いた溶湯浸透法によるSiC反応焼結体の作製とその機械的性質

    花田 喜嗣, 肖 陽, 山本 厚生, 徳永 辰也, 恵良 秀則

    鋳造工学  ( 公益社団法人 日本鋳造工学会 )  91 ( 10 ) 710 - 716   2019年10月  [査読有り]

     概要を見る

    <p>  Structure and mechanical properties of SiC fabricated by the reaction sintering method have been investigated by varying the blending composition of Si, C and SiC powders. First, specimens of the first-sintered body were formed at 473 K under a pressure of 20 MPa in a metallic mold and then sintered by heating at 973 K for 3.6 ks in Ar gas atmosphere. The first-sintered specimens were next put into a graphite mold to set Fe-75mass%Si alloy, which is often used as an inoculation agent, on the specimens and then held at 1693 K for 900 s in a vacuum furnace under a pressure of 10-1 Pa. Finally, SiC was successfully performed as a second-sintered body through the infiltration of Fe-75%Si alloy melt into the porous first-sintered body, which was followed by their mutual reaction. The microstructure and distributions of Fe and Si elements were observed using laser microscope and EPMA respectively. The hardness and fracture toughness were measured using a micro-Vickers hardness tester.</p><p>  The results indicate good infiltration of Fe-75%Si alloy melt into the first sintered body and that the second sintered body had a small amount of porosity. Iron carbides could not be found in the sintered structure but finely distributed iron silicides of FeSi and FeSi<sub>2</sub> were found. Furthermore, the fracture toughness of the body increased with increasing C content in the first sintered body. The mechanical properties were improved more than that of conventional sintered SiC when Fe-Si alloy was employed. The improvement in the properties is thought to be due to the uniform and fine distribution of FeSi, FeSi<sub>2</sub> and SiC in the matrix.</p>

    DOI CiNii

  • Effect of Nickel Content on Microstructural Evolution in Austempered Solution-Strengthened Ferritic Ductile Cast Iron

    Tokunaga T., Kim Y., Era H.

    Journal of Materials Engineering and Performance    28 ( 7 ) 4034 - 4040   2019年07月  [査読有り]

     概要を見る

    © 2019, ASM International. The effects of Ni content and austempering temperature on microstructural evolution during austempering in solution-strengthened ferritic ductile cast iron with Ni contents between 0 and 1.1 mass% were investigated. The microstructure observation for the samples austempered at temperatures between 375 and 325 °C using an infrared gold image furnace was carried out with optical microscopy, x-ray diffraction measurements, and electron back-scattered diffraction pattern (EBSP) analysis. In addition, the Vickers hardness of both the austempered and as-quenched samples was measured under a load of 0.9807 N. According to the microstructure observations, the matrix of the samples austempered at temperatures between 375 and 325 °C exhibited finer acicular ferrite microstructure with increasing Ni content. Optical microscopy and EBSP analysis revealed that the amount of high-carbon austenite phase for the austempered samples increased with increasing Ni content and austempering temperature. Although samples with higher Ni content were found to contain more high-carbon austenite phase in the matrix, the Vickers hardness of the samples tended to increase with increasing Ni content at the same austempering temperature. The reason for this may be the higher carbon content in the matrix of the samples with higher Ni contents.

    DOI Scopus

  • Effect of Nickel Content on Microstructural Evolution in Austempered Solution-Strengthened Ferritic Ductile Cast Iron

    Tatsuya Tokunaga, Yeong-Jin Kim, Hidenori Era

    Proceedings of the 73rd World Foundry Congress      2 pages   2018年09月  [査読有り]

    Poland  Krakow  2018年09月  -  2018年09月

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著書 【 表示 / 非表示

  • 新版 鉄鋼材料と合金元素

    一般社団法人日本鉄鋼協会 鉄鋼材料と合金元素編集委員会 ( 共編者 , 担当範囲: 応用編第4章の4.2.4節から4.2.6節(5ページ)および第15章15.2.1節(4ページ)を分担執筆した. )

    一般社団法人日本鉄鋼協会  2015年11月 ISBN: 4930980879

     概要を見る

    本書は,鉄鋼材料における合金元素の役割を学術と応用の面から網羅するものである.学官界79名,産業界107名の執筆により,基礎編および応用編を併せて1076ページからなる.

口頭発表・ポスター発表等 【 表示 / 非表示

  • FeCoNiCrBSi系合金における組織形成の評価

    Yicheng Zhang,徳永辰也,恵良秀則

    日本金属学会第165回秋期講演大会  (岡山大学)  2019年09月  -  2019年09月    日本金属学会

  • 合金中の積層欠陥における溶質元素の偏析挙動の熱力学的評価

    徳永辰也,和泉勇樹,恵良秀則

    日本金属学会第165回秋期講演大会  (岡山大学)  2019年09月  -  2019年09月    日本金属学会

  • Thermodynamic Evaluation of Grain Boundary Segregation and Precipitation Behavior in Steels

    Tatsuya Tokunaga, Yuta Motomura, Hidenori Era, Hiroshi Ohtani

    CALPHAD XLVIII  (Singapore)  2019年06月  -  2019年06月   

  • Fe-Co-Ni-Cr-B-Si系ハイエントロピー合金における組織形成とその熱的安定性の評価

    Yicheng Zhang,徳永辰也,恵良秀則

    日本金属学会第164回春期講演大会  2019年03月  -  2019年03月   

  • Thermodynamic Study on Segregation of Solute Elements to Stacking Faults in Some Binary Alloy Systems

    Tatsuya Tokunaga, Hidenori Era

    LPSO2018  2018年12月  -  2018年12月   

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学術関係受賞 【 表示 / 非表示

  • 2018 Rolls Technology Best Paper Award

    2018年05月07日   Association for Iron & Steel Technology   アメリカ合衆国

    受賞者:  Nozomu Oda, Yasunori Ozaki, Takumi Oohata, Paul Fleiner, Tasuya Tokunaga, Hidenori Era

  • H27年度シンクロLPSO研究成果報告会 優秀ポスター賞

    2016年03月04日   文部科学省科学研究費補助金「新学術領域研究」シンクロ型LPSO構造の材料科学-次世代軽量構造材料への革新的展開‐   日本国

    受賞者:  徳永辰也

科研費獲得実績 【 表示 / 非表示

  • 熱量測定に基づく高クロム鋼のミクロ組織状態変化の定量評価

    基盤研究(C)

    研究期間:  2014年04月  -  2017年03月

    研究課題番号:  26420726

  • 超高強度マグネシウム合金の相変態挙動に基づくLPSO構造形成メカニズムの解明

    新学術領域研究

    研究期間:  2012年04月  -  2014年03月

    研究課題番号:  24109507

 

担当授業科目 【 表示 / 非表示

  • 2019年度  材料相変態特論

  • 2019年度  材料組織学Ⅰ

  • 2018年度  材料相変態特論

  • 2018年度  材料組織学Ⅰ

  • 2017年度  材料組織学Ⅰ

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