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Affiliation Department |
Department of Physical Science and Engineering
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Title |
Assistant Professor |
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External Link |
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TOKUNAGA Toko
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From School
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Hokkaido University Graduate School of Engineering, Graduated
2013.04 - 2015.06
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AGH University of Science and Technology Faculty of Metals Engineering and Industrial Computer Science Graduated
2013.04 - 2015
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Hokkaido University Graduate School of Engineering Graduated
2011.04 - 2013.03
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Hokkaido University Faculty of Engineering Graduated
2007.04 - 2011.03
Papers
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Kink-band formation in the directionally-solidified Mg/LPSO two-phase alloys Reviewed
T. Tokunaga, K. Hagihara, M. Yamasaki, T. Mayama, K. Yamamoto, H. Narimoto, T. Kida, Y. Kawamura, T. Nakano
Science and Technology of Advanced Materials 2022.10
Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)
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Microstructural factors governing the significant strengthening of Al/Al2Cu mille-feuille structured alloys accompanied by kink-band formation Reviewed International coauthorship
K. Hagihara, T. Tokunaga, S. Ohsawa, S. Uemichi, K. Guan, D. Egusa, E.Abe
International Journal of Plasticity 158 103419 2022.09
Language：English Publishing type：Research paper (scientific journal)
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青森県量子科学センターにおけるBNCT
Toko Tokunaga, Shingo Hachinohe, Hiroyoshi Kikuchi, Toyomi Baba
36 ( 2 ) 62 - 63 2021.02
Publishing type：Research paper (scientific journal)
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Development of High Corrosion- and Wear-Resistant Al-Si Alloy Coating on AZ80 Mg Alloy by Hot Extrusion Reviewed
Toko Tokunaga, Kazushi Sotomoto, Munekazu Ohno, Kiyotaka Matsuura
Journal of Materials Engineering and Performance 29 6355 - 6362 2020
Language：English Publishing type：Research paper (scientific journal)
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Microstructure refinement and mechanical properties improvement of Al-Si-Fe alloys by hot extrusion using a specially designed high-strain die Reviewed
Sakow Shino, Toko Tokunaga, Munekazu Ohno, Kiyotaka Matsuura
Journal of Materials Processing Technology 277 ( 116447 ) 1 - 9 2020
Language：English Publishing type：Research paper (scientific journal)
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Enhancement of ductility for Al–Si–Fe alloy by refining β phase with a novel ball-die extrusion Reviewed
Toko Tokunaga, Haruki Inubushi
SN Applied Sciences 1 ( 10 ) 1334 2019.10
Language：English Publishing type：Research paper (scientific journal) Publisher：Springer Science and Business Media LLC
DOI： 10.1007/s42452-019-1377-4
Other Link： http://link.springer.com/article/10.1007/s42452-019-1377-4/fulltext.html
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Microstructure evolution during superplastic deformation of an Al-coated Mg alloy sheet Reviewed
T. Tokunaga, M. Ohno
Journal of Alloys and Compounds 805 436 - 443 2019
Language：English Publishing type：Research paper (scientific journal)
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Fabrication of Al-Coated Mg-Li Alloy Sheet and Investigation of Its Properties Reviewed
T. L. Zhang, T. Tokunaga, M. Ohno, M. L. Zhang, K. Matsuura
Acta Metallurgica Sinica (English Letters) 32 169 - 177 2019
Language：English Publishing type：Research paper (scientific journal)
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Coating on magnesium alloy with super duralumin by hot extrusion and evaluation of its surface properties Reviewed
Toko Tokunaga, Kazushi Sotomoto, Munekazu Ohno, Kiyotaka Matsuura
Materials Transactions 59 ( 3 ) 432 - 436 2018
Language：English Publishing type：Research paper (scientific journal) Publisher：Japan Institute of Metals (JIM)
The poor corrosion resistance of Mg alloys, which is well known as one of the lightest structural metal materials, limits a wide use of these alloys. In order to dramatically increase not only the corrosion resistance but also the surface hardness of Mg alloys (AZ80), coating with A2024 Al alloy by hot extrusion has been attempted in this study. The coating was successfully realized by hot extrusion of a Mg alloy (AZ80) billet together with an Al alloy plate placed between the billet and the extrusion die. The A2024 Al alloy-coated Mg alloy exhibited an excellent corrosion resistance and no weight loss was observed after immersion in a 5 mass% HCl aqueous solution for 10 min while a weight loss of about 1500 g･m−2 was observed in case of AZ80 Mg alloy without coating under the same condition. The surface hardness of the coated alloy was increased to about 85 HV by aging for 144 h at room temperature after solution treatment for 3 h at 673 K.
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Brazed Bonding between SiAlON and heat-resistant alloys with application of filler materials Reviewed
Toko Tokunaga, Masayuki Koshiyama, Kazuya Kurokawa, Munekazu Ohno, Kiyotaka Matsuura
Materials Transactions 59 ( 6 ) 969 - 975 2018
Language：English Publishing type：Research paper (scientific journal) Publisher：Japan Institute of Metals (JIM)
It has been required to improve the heat efficiency of thermal power generation system for the sake of mitigation of the global warming and resource depletion problems. For improving the heat efficiency, it is effective to increase the steam temperature, and as a result, appropriate heatresistant alloys are needed. Although SUS304 stainless steel and Ni-based superalloys have been proposed as promising heat-resistant alloys until now, there still remain some concerns such as high-temperature corrosion by flaming gas and erosion by combustion ash. Thus, the present authors propose SiAlON ceramic coating on SUS304 and INCONEL X-750 because SiAlON has excellent heat, wear and corrosion resistances. In the present study, brazed bonding between SiAlON and these heat-resistant alloys was attempted with the applications of Cu and Ag as a soft filler material to reduce the residual stress generated due to the difference in thermal expansion coefficient between SiAlON and the heat-resistant alloys. As for the bonding with the Cu filler, the SiAlON/Cu/SUS joint was successful when the brazing time was short. However, when the brazing time was long (for example, 60 minutes), Fe-based grains were formed in the Cu filler layer, and the cracks were formed in the SiAlON near the joint interface during cooling in the brazing process. It was considered that the Cu filler was hardened by the formation of the Fe-based grains and could not reduce the residual stress. As for the bonding with the Ag filler, on the other hand, the SiAlON/Ag/SUS joint was successful even for a long brazing time. The SiAlON/Ag/INCONEL joint was also successful. The bending strengths of these SiAlON/Cu/SUS, SiAlON/Ag/SUS and SiAlON/Ag/INCONEL joints were evaluated by a three point bending test, and the results were approximately 200, 270 and 350 MPa, respectively. In all cases fracture occurred in the SiAlON, which means that the SiAlON and the alloys were strongly bonded.
Misc
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Al，Mg基先進的高機能性構造材料の創製に関する研究 Invited
徳永透子
72 618 - 618 2022.10
Authorship：Lead author, Corresponding author Language：Japanese Publishing type：Article, review, commentary, editorial, etc. (other)
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芯のある研究者を目指して
徳永透子
54 ( 12 ) 639 2015
Publishing type：Article, review, commentary, editorial, etc. (bulletin of university, research institution)
Presentations
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各種組織制御による軽金属材料の強度・機能性向上
徳永透子
一般社団法人軽金属学会第143回秋期大会 2022.11
Event date： 2022.11
Language：Japanese Presentation type：Oral presentation (invited, special)
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AE測定によるMg97Zn1Y2合金押出材の引張変形挙動の解明
堀口 皓匠、山崎 倫昭、眞山 剛、萩原 幸司、徳永 透子，Daria Drozdenko，Kristián Máthis
一般社団法人軽金属学会第143回秋期大会 2022.11
Event date： 2022.11
Language：Japanese Presentation type：Poster presentation
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Mg/LPSO複相合金の組織と力学特性の相関
萩原幸司，徳永 透子，山崎倫昭，眞山剛，山本和輝，杉田三佳
一般社団法人軽金属学会第143回秋期大会 2022.11
Event date： 2022.11
Language：Japanese Presentation type：Oral presentation (general)
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AE測定によるLPSO型Mg-Zn-Y合金の引張変形挙動の解明
堀口 皓匠、山崎 倫昭、眞山 剛、萩原 幸司、徳永 透子、Drozdenko Daria、Máthis Kristián
日本金属学会 2022年秋期講演大会（第171回大会） 2022.09
Event date： 2022.09
Language：Japanese Presentation type：Poster presentation
Venue：福岡
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硬X線光電子分光によるMg-Zn-Y合金の擬ギャップの観測
宮崎 秀俊、赤塚 達吉、木村 耕治、江草 大佑、佐藤 庸平、板倉 充洋、徳永 透子、林 好一、萩原 幸司、阿部 英司
日本金属学会 2022年秋期講演大会（第171回大会） 2022.09
Event date： 2022.09
Language：Japanese Presentation type：Oral presentation (general)
Venue：福岡
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Mg/LPSO複相合金の強化挙動の統一的理解
山本 和輝、萩原 幸司、徳永 透子、山崎 倫昭、眞山 剛、河村 能人、中野 貴由
日本金属学会 2022年秋期講演大会（第171回大会） 2022.09
Event date： 2022.09
Language：Japanese Presentation type：Poster presentation
Venue：福岡
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Al/Al2Cu組織型ミルフィーユ材料の力学特性支配因子
大澤 周平、萩原 幸司、徳永 透子
日本金属学会 2022年秋期講演大会（第171回大会） 2022.09
Event date： 2022.09
Language：Japanese Presentation type：Poster presentation
Venue：福岡
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各種組織制御による金属材料の強度・機能性向上 Invited
徳永 透子
日本金属学会 2022年秋期講演大会（第171回大会） 2022.09
Event date： 2022.09
Language：Japanese Presentation type：Oral presentation (invited, special)
Venue：福岡
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その場中性子回折実験によるMg-Zn-Y合金の引張変形機構の考察
徳永 透子，山崎 倫昭，眞山 剛，ハルヨ ステファヌス，ゴン ウー，飯塚 拓実，萩原 幸司
一般社団法人軽金属学会 第142回春期大会 2022.05
Event date： 2022.05
Language：Japanese
Venue：オンライン
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Al基共晶型ミルフィーユ材料の力学特性支配因子の解明
萩原 幸司，徳永 透子，大澤 周平
一般社団法人軽金属学会 第142回春期大会 2022.05
Event date： 2022.05
Language：Japanese Presentation type：Oral presentation (general)
Venue：オンライン
Awards
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第40回軽金属奨励賞
2022.11 一般社団法人軽金属学会 アルミニウム，マグネシウム基先進的高機能性構造材料の創製に関する研究
徳永透子
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第32回 日本金属学会奨励賞
2022.09 日本金属学会 各種金属材料の組織制御による強度・機能性向上に関する研究
徳永透子
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優秀発表賞
2022.03 新学術領域研究「ミルフィーユ構造の材料科学」 一方向性凝固Mg/LPSO二相合金におけるキンク強化
徳永透子
Award type：Award from Japanese society, conference, symposium, etc.
Teaching Experience
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物理学演習Ⅱ
2022.10 Institution：Nagoya Institute of Technology
Level：Undergraduate (liberal arts)
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材料機能工学演習Ⅱ
2021.04 Institution：Nagoya Institute of Technology
Level：Undergraduate (specialized)
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材料機能工学演習Ⅰ
2021.04 Institution：Nagoya Institute of Technology
Level：Undergraduate (specialized)
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物理学演習Ⅰ
2021.04 Institution：Nagoya Institute of Technology
Level：Undergraduate (liberal arts)
Committee Memberships
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日本金属学会 会報編集委員（第３分野世話人）
2019.04
Committee type：Academic society
Social Activities
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私が食べられないミルフィーユの話をすることになったわけ
Role(s)： Lecturer
精密工学会北陸信越支部 精密工学会北陸信越支部特別講演会＋ワークショップ 2022.08