Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
Shigeto Yamasaki Last modified date:2024.01.11

Associate Professor / Department of Materials Science and Engineering / Faculty of Engineering


Papers
1. Kawano, Y., Mayama, T., Mitsuhara, M., Yamasaki, S. & Sato, M., Generalized Slip Operation Factor Considering Contribution of Secondary Slip Systems, Materials Today Communications, 2021.03.
2. Suematsu, K., Harano, W., Yamasaki, S., Watanabe, K. & Shimanoe, K., One-trillionth level toluene detection using a dual-designed semiconductor gas sensor: Material and sensor-driven designs, ACS Applied Electronic Materials, 2020.11.
3. Shigeto Yamasaki, Tsubasa Tokuzumi Wansong Li, Masatoshi Mitsuhara, Koji Hagihara, Toshiyuki Fujii, Hideharu Nakashima, Kink Formation Process in Long-Period Stacking Ordered Mg-Zn-Y Alloy, Acta Materialia, https://doi.org/10.1016/j.actamat.2020.04.051, 195, 15, 25-34, 2020.08.
4. Tsubasa Tokuzumi, Shigeto Yamasaki, Wansong Li, Masatoshi Mitsuhara, Hideharu Nakashima, Morphological and crystallographic features of kink bands in long-period stacking ordered Mg-Zn-Y alloy analyzed by serial sectioning SEM-EBSD observation method, Materialia, https://doi.org/10.1016/j.mtla.2020.100716, 12, 100716, 2020.08.
5. Wansong Li, Shigeto Yamasaki, Masatoshi Mitsuhara, Hideharu Nakashima, In situ EBSD study of deformation behavior of primary α phase in a bimodal Ti-6Al-4V alloy during uniaxial tensile tests, Materials Characterization, 10.1016/j.matchar.2020.110282, 163, 2020.05.
6. Satoshi Hata, Hiromitsu Furukawa, Takashi Gondo, Daisuke Hirakami, Noritaka Horii, Ken Ichi Ikeda, Katsumi Kawamoto, Kosuke Kimura, Syo Matsumura, Masatoshi Mitsuhara, Hiroya Miyazaki, Shinsuke Miyazaki, Mitsu Mitsuhiro Murayama, Hideharu Nakashima, Hikaru Saito, Masashi Sakamoto, Shigeto Yamasaki, Electron tomography imaging methods with diffraction contrast for materials research
, Microscopy, 10.1093/jmicro/dfaa002, 69, 3, 141-155, 2020.05.
7. Satoshi Hata, Hiromitsu Furukawa, Takashi Gondo, Daisuke Hirakami, Noritaka Horii, Ken Ichi Ikeda, Katsumi Kawamoto, Kosuke Kimura, Syo Matsumura, Masatoshi Mitsuhara, Hiroya Miyazaki, Shinsuke Miyazaki, Mitsu Mitsuhiro Murayama, Hideharu Nakashima, Hikaru Saito, Masashi Sakamoto, Shigeto Yamasaki, Electron tomography imaging methods with diffraction contrast for materials research, Microscopy, 10.1093/jmicro/dfaa002, 69, 3, 141-155, 2020.03, © 2020 The Author(s). Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. Transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) enable the visualization of three-dimensional (3D) microstructures ranging from atomic to micrometer scales using 3D reconstruction techniques based on computed tomography algorithms. This 3D microscopy method is called electron tomography (ET) and has been utilized in the fields of materials science and engineering for more than two decades. Although atomic resolution is one of the current topics in ET research, the development and deployment of intermediate-resolution (non-atomic-resolution) ET imaging methods have garnered considerable attention from researchers. This research trend is probably not irrelevant due to the fact that the spatial resolution and functionality of 3D imaging methods of scanning electron microscopy (SEM) and X-ray microscopy have come to overlap with those of ET. In other words, there may be multiple ways to carry out 3D visualization using different microscopy methods for nanometer-scale objects in materials. From the above standpoint, this review paper aims to (i) describe the current status and issues of intermediate-resolution ET with regard to enhancing the effectiveness of TEM/STEM imaging and (ii) discuss promising applications of state-of-the-art intermediate-resolution ET for materials research with a particular focus on diffraction contrast ET for crystalline microstructures (superlattice domains and dislocations) including a demonstration of in situ dislocation tomography..
8. Yoshiki Kawano, Michihiro Sato, Tsuyoshi Mayama, Masatoshi Mitsuhara, Shigeto Yamasaki, Quantitative evaluation of slip activity in polycrystalline α-titanium considering non-local interactions between crystal grains, International Journal of Plasticity, 10.1016/j.ijplas.2019.12.001, 127, 2020.01.
9. Shigeto Yamasaki, Tomo Okuhira, Masatoshi Mitsuhara, Hideharu Nakashima, Jun Kusui, Mitsuru Adachi, Effect of Fe addition on heat-resistant aluminum alloys produced by selective laser melting, Metals, 10.3390/met9040468, 9, 4, 2019.04.
10. Yuki Uchida, Sho Nakandakari, Kenji Kawahara, Shigeto Yamasaki, Masatoshi Mitsuhara, Hiroki Ago, Controlled Growth of Large-Area Uniform Multilayer Hexagonal Boron Nitride as an Effective 2D Substrate, ACS nano, 10.1021/acsnano.8b03055, 12, 6, 6236-6244, 2018.06.
11. Yuki Uchida, Sho Nakandakari, Kenji Kawahara, Shigeto Yamasaki, Masatoshi Mitsuhara, Hiroki Ago, Controlled Growth of Large-Area Uniform Multilayer Hexagonal Boron Nitride as an Effective 2D Substrate, ACS Nano, 10.1021/acsnano.8b03055, 12, 6, 6236-6244, 2018.06, © Copyright 2018 American Chemical Society. Multilayer hexagonal boron nitride (h-BN) is an ideal insulator for two-dimensional (2D) materials, such as graphene and transition metal dichalcogenides, because h-BN screens out influences from surroundings, allowing one to observe intrinsic physical properties of the 2D materials. However, the synthesis of large and uniform multilayer h-BN is still very challenging because it is difficult to control the segregation process of B and N atoms from metal catalysts during chemical vapor deposition (CVD) growth. Here, we demonstrate CVD growth of multilayer h-BN with high uniformity by using the Ni-Fe alloy film and borazine (B3H6N3) as catalyst and precursor, respectively. Combining Ni and Fe metals tunes the solubilities of B and N atoms and, at the same time, allows one to engineer the metal crystallinity, which stimulates the uniform segregation of multilayer h-BN. Furthermore, we demonstrate that triangular WS2 grains grown on the h-BN show photoluminescence stronger than that grown on a bare SiO2 substrate. The PL line width of WS2/h-BN (the minimum and mean widths are 24 and 43 meV, respectively) is much narrower than those of WS2/SiO2 (44 and 67 meV), indicating the effectiveness of our CVD-grown multilayer h-BN as an insulating layer. Large-area, multilayer h-BN realized in this work will provide an excellent platform for developing practical applications of 2D materials..
12. Shigeto Yamasaki, Masatoshi Mitsuhara, Hideharu Nakashima, Development of high-chromium ferritic heat-resistant steels with high nitrogen content, isij international, 10.2355/isijinternational.ISIJINT-2017-758, 58, 6, 1146-1154, 2018.01.
13. Masayuki Takano, Keiji Kuroda, Kohei Hase, Shuuto Tanaka, Shigeto Yamasaki, Masatoshi Mitsuhara, Hideharu Nakashima, Effect of Bi or Sb addition on high temperature deformation behavior in Sn-Cu-Ni solder alloys, Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals, 10.2320/jinstmet.J2017025, 81, 11, 502-509, 2017.09.
14. Motomichi Koyama, Keita Yamanouchi, Qinghua Wang, Shien Ri, Yoshihisa Tanaka, Yasuaki Hamano, Shigeto Yamasaki, Masatoshi Mitsuhara, Masataka Ohkubo, Hiroshi Noguchi, Kaneaki Tsuzaki, Multiscale in situ deformation experiments
A sequential process from strain localization to failure in a laminated Ti-6Al-4V alloy, Materials Characterization, 10.1016/j.matchar.2017.04.010, 128, 217-225, 2017.06.
15. Motomichi Koyama, Keita Yamanouchi, Qinghua Wang, Shien Ri, Yoshihisa Tanaka, Yasuaki Hamano, Shigeto Yamasaki, Masatoshi Mitsuhara, Masataka Ohkubo, Hiroshi Noguchi, Kaneaki Tsuzaki, Multiscale in situ deformation experiments: A sequential process from strain localization to failure in a laminated Ti-6Al-4V alloy, Materials Characterization, 10.1016/j.matchar.2017.04.010, 128, 217-225, 2017.06, © 2017 Elsevier Inc. The microscopic factors causing tensile failure of an α/β laminated Ti-6Al-4V alloy were investigated through in situ scanning electron microscopy and sampling moiré at an ambient temperature. Specifically, multiscale in situ microscopic observations were conducted to extract the most crucial factor of the failure. Slip localization in the vicinity of an intergranular α-sheet was clarified to be the primary factor that causes failure of the Ti-6Al-4V alloy. In addition, no relationship between interfacial strain localization and macroscopic shear localization at 45 degrees against the tensile direction was observed..
16. Shigeto Yamasaki, Masatoshi Mitsuhara, Hideharu Nakashima, Deformation microstructure and fracture behavior in creep-exposed Alloy 617, Materials Transactions, 10.2320/matertrans.M2016407, 58, 3, 442-449, 2017.01.
17. Masayuki Takano, Keiji Kuroda, Kohei Hase, Shuuto Tanaka, Shigeto Yamasaki, Masatoshi Mitsuhara, Hideharu Nakashima, Effect of Cu and Ni addition on high temperature deformation behavior in Sn-Cu-Ni solder alloys, Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals, 10.2320/jinstmet.J2016069, 81, 7, 337-344, 2017.01.
18. Takanori Ito, Shigeto Yamasaki, Masatoshi Mitsuhara, Minoru Nishida, Mitsuharu Yonemura, Effect of intergranular carbides on creep strength in nickel-based heat-resistant alloys, Materials Transactions, 10.2320/matertrans.M2016291, 58, 1, 52-58, 2017.01.
19. Shigeto Yamasaki, Masatoshi Mitsuhara, Hideharu Nakashima, Mitsuharu Yonemura, Evaluation of local creep strain in face-centred cubic heatresistant alloys using electron backscattered diffraction analysis, isij international, 10.2355/isijinternational.ISIJINT-2016-712, 57, 5, 851-856, 2017.01.
20. Takanori Ito, Shigeto Yamasaki, Masatoshi Mitsuhara, Hideharu Nakashima, Minoru Nishida, Mitsuharu Yonemura, Microstructure and creep property in polycrystalline Ni-based alloy with intergranular intermetallics, Tetsu-To-Hagane/Journal of the Iron and Steel Institute of Japan, 10.2355/tetsutohagane.TETSU-2016-107, 103, 7, 434-442, 2017.01.
21. Masatoshi Mitsuhara, Shigeto Yamasaki, Masaki Miake, Hideharu Nakashima, Minoru Nishida, Junichi Kusumoto, Akihiro Kanaya, Creep strengthening by lath boundaries in 9Cr ferritic heat-resistant steel, Philosophical Magazine Letters, 10.1080/09500839.2016.1154200, 96, 2, 76-83, 2016.02.
22. Masatoshi Mitsuhara, Shigeto Yamasaki, Masaki Miake, Hideharu Nakashima, Minoru Nishida, Junichi Kusumoto, Akihiro Kanaya, Creep strengthening by lath boundaries in 9Cr ferritic heat-resistant steel, Philosophical Magazine Letters, 10.1080/09500839.2016.1154200, 96, 2, 76-83, 2016.02, © 2016 Taylor and Francis. The interactions between dislocations and lath boundaries in Grade 91 steel were observed by an in situ transmission electron microscopy tensile test at 973 K. Dislocations glided slowly and bowed out in a martensite lath interior. The ends of the dislocation were connected to the lath boundaries. In a tempered specimen, the pinning stress caused by the lath boundary was estimated to be >70 MPa with a lath width of 0.4 m. In crept specimens, lath coarsening reduced the pinning effect..
23. S. Yamasaki, M. Mitsuhara, K. Ikeda, S. Hata, H. Nakashima, 3D visualization of dislocation arrangement using scanning electron microscope serial sectioning method, Scripta Materialia, 10.1016/j.scriptamat.2015.02.001, 101, 80-83, 2015.05.
24. S. Yamasaki, M. Mitsuhara, K. Ikeda, S. Hata, H. Nakashima, 3D visualization of dislocation arrangement using scanning electron microscope serial sectioning method, Scripta Materialia, 10.1016/j.scriptamat.2015.02.001, 101, 80-83, 2015.05, © 2015 Acta Materialia Inc. Published by Elsevier Ltd. We performed the three-dimensional visualization of dislocations through serial sectioning and use of SEM electron channeling contrast (ECC) images for a crept nickel-based alloy. We successfully reconstructed a volume of approximately 7.5 μm3, including dislocation arrangements, by performing calculations based on the continuous tomograms of ECC images. By incorporating the information on crystal orientation obtained by the electron back-scattered diffraction, we verified that the three-dimensional arrangement of dislocations, such as slip plane, was accurately reflected in the three-dimensional volume..
25. Shigeto Yamasaki, Masatoshi Mitsuhara, Ken Ichi Ikeda, Satoshi Hata, Hideharu Nakashima, Low-stress creep deformation in long-term aged ferritic heat-resistant steel, Materials Transactions, 10.2320/matertrans.M2013427, 55, 5, 842-849, 2014.05.
26. 純ニッケルの極低ひずみ速度クリープの変形機構の解明.
27. オーステナイト系耐熱鋼の局所結晶方位解析によるクリープひずみの評価.
28. SEM/EBSD法によるクリープ変形に伴うGr.92鋼溶接継手の組織変化挙動解析.
29. フェライト系耐熱鋼の低応力クリープ変形挙動.
30. 局所方位解析法を用いたフェライト系耐熱鋼溶接熱影響部クリープ弱化要因の特定.
31. Junjie Shen, Shigeto Yamasaki, Ken Ichi Ikeda, Satoshi Hata, Hideharu Nakashima, Low-temperature creep at ultra-low strain rates in pure aluminum studied by a helicoid spring specimen technique, Materials Transactions, 10.2320/matertrans.M2010405, 52, 7, 1381-1387, 2011.07.
32. Junjie Shen, Shigeto Yamasaki, Ken Ichi Ikeda, Satoshi Hata, Hideharu Nakashima, Low-temperature creep at ultra-low strain rates in pure aluminum studied by a helicoid spring specimen technique, Materials Transactions, 10.2320/matertrans.M2010405, 52, 7, 1381-1387, 2011.07, The creep behavior in pure aluminum has been investigated by helicoid spring creep tests at strain rates, ε̇, lower than 10-10 s-1 and low temperature ranging from 0.32Tm to 0.43T m. It was found that the creep behavior in this region depends strongly on grain sizes and impurity concentrations. For high-purity aluminum (5 N Al) with an average grain size, dg > 1600 μm, nearly the wire diameter of the spring sample, where the role of grain boundary during creep deformation can be negligible, the stress exponent was n ∼ 5 and the activation energy was Qc = 32 kJ/mol. Microstructural observation showed the formation of large dislocation cells (∼10μm) and tangled dislocations at the cell walls. For high-purity aluminum (5N Al) with d g = 24 μm, the stress exponent was n ∼ 1 and the activation energy was Qc = 15kJ/mol. On the other hand, for commercial low-purity aluminum (2 N Al) with dg = 25 μm, the stress exponent was n = 2 and the activation energy was Qc = 25 kJ/mol. Microstructural observations revealed dislocations emitted from grain boundaries, those dislocations interacting with intragranular dislocations and the formation of dislocation cells in the grains. Based on those experimental results, the low-temperature creep mechanisms in pure aluminum at ε̇
33. Three-dimensional Microstructure and High Temperature Strength in ODS 9Cr Ferritic Heat Resistant Steels
Oxide-dispersion-strengthened (ODS) 9Cr ferritic heat resistant steel is a leading candidate for a cladding material used in advanced fast reactor fuels because of its superior radiation resistance and high-temperature strength. In this study, distribution of oxides, which is presumed to be a dominant factor of the high-temperature strength, has been evaluated by three-dimensional (3D) observations using electron tomography. The oxide distribution was classified into two regions, whose number densities were high or low. Dislocation pinning forces caused by the oxides were estimated from the 3D data in each region. A good coincidence was recognized between the force in the low-density region and a threshold stress at which the creep deformation mechanism changes. Therefore, the high temperature deformation behavior of ODS steels is influenced by dislocation motions in the low-density regions of oxides..
34. コイルばねクリープ試験法による改良9Cr‐1Mo鋼の極低速クリープ挙動評価.
35. Pt系分散強化合金の低応力領域でのクリープ特性の検討.
36. コイルばねクリープ試験法による高Cr鋼の低速クリープ挙動評価.
37. コイルばねクリープ試験法によるSUS304鋼のクリープ挙動解析.