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Analysis on dislocation theory model for local deformation behavior in bcc metal through TEM in-situ straining technique

Research Project

Project/Area Number 18H01696
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section一般
Review Section Basic Section 26010:Metallic material properties-related
Research InstitutionNational Institute for Materials Science

Principal Investigator

OHMURA Takahito  国立研究開発法人物質・材料研究機構, 構造材料研究拠点, 副拠点長 (40343884)

Co-Investigator(Kenkyū-buntansha) 井 誠一郎  国立研究開発法人物質・材料研究機構, 構造材料研究拠点, 主幹研究員 (60435146)
Project Period (FY) 2018-04-01 – 2021-03-31
Project Status Completed (Fiscal Year 2020)
Budget Amount *help
¥15,470,000 (Direct Cost: ¥11,900,000、Indirect Cost: ¥3,570,000)
Fiscal Year 2020: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2019: ¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000)
Fiscal Year 2018: ¥6,500,000 (Direct Cost: ¥5,000,000、Indirect Cost: ¥1,500,000)
Keywords転位 / BCC金属 / 塑性変形 / 局所力学挙動 / TEM / 粒界 / BCC金属
Outline of Final Research Achievements

TEM in-situ straining measurements for interstitial-free steel revealed that dislocations in grain interior moved to a grain boundary and were absorbed at the grain boundary during deformation. The corresponding stress-strain relation showed remarkable stress increase due to the reduction of the dislocation density. For further deformation stage, dislocations nucleated at a grain boundary to lead an increase in dislocation density. Nanoindentation measurements for Fe single crystal revealed that the strain burst phenomenon occur at the transition from elastic to plastic deformation, which showed a Gaussian distribution of probability density. In the subsequent stage of the deformation, the strain burst phenomenon presented power-law function, which is totally different physical model of the deformation.

Academic Significance and Societal Importance of the Research Achievements

bcc金属は,鉄鋼材料に代表されるように身近な構造材料であり,社会インフラを支える重要な役割を果たしている。学術的には,bcc結晶構造に特有の転位運動と力学挙動の関係をTEM内その場変形などの先進的な手法によって直接的に捉えることに成功し,塑性変形の機構を解明した。社会的には,変形機構の基礎的な解明によって機械的性質のさらなる性能向上を実現する指針の構築に貢献した。

Report

(4 results)
  • 2020 Annual Research Report   Final Research Report ( PDF )
  • 2019 Annual Research Report
  • 2018 Annual Research Report
  • Research Products

    (17 results)

All 2021 2020 2019 2018 Other

All Int'l Joint Research (2 results) Journal Article (11 results) (of which Int'l Joint Research: 3 results,  Peer Reviewed: 11 results,  Open Access: 5 results) Presentation (4 results) (of which Int'l Joint Research: 4 results,  Invited: 4 results)

  • [Int'l Joint Research] 国立台湾大学(その他の国・地域 台湾)

    • Related Report
      2019 Annual Research Report
  • [Int'l Joint Research] 国立台湾大学(その他の国・地域 台湾)

    • Related Report
      2018 Annual Research Report
  • [Journal Article] Recent Advances in Indentation Techniques and Their Application to Mechanical Characterization2021

    • Author(s)
      Ohmura Takahito
    • Journal Title

      MATERIALS TRANSACTIONS

      Volume: 62 Issue: 4 Pages: 563-569

    • DOI

      10.2320/matertrans.MT-M2020371

    • NAID

      130008002791

    • ISSN
      1345-9678, 1347-5320
    • Year and Date
      2021-04-01
    • Related Report
      2020 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] Evaluation of Grain Boundary Strength through Nanoindentation Technique2021

    • Author(s)
      Nakano Katsuya、Takeda Kengo、Ii Seiichiro、Ohmura Takahito
    • Journal Title

      Journal of the Japan Institute of Metals and Materials

      Volume: 85 Issue: 1 Pages: 40-48

    • DOI

      10.2320/jinstmet.JD202006

    • NAID

      130007959978

    • ISSN
      0021-4876, 1880-6880, 2433-7501
    • Year and Date
      2021-01-01
    • Related Report
      2020 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] Effects of Grain Boundary Geometry and Boron Addition on the Local Mechanical Behavior of Interstitial-Free (IF) Steels2021

    • Author(s)
      Endoh Kazuki、Ii Seiichiro、Kimura Yuuji、Sasaki Taisuke、Goto Sota、Yokota Takeshi、Ohmura Takahito
    • Journal Title

      Journal of the Japan Institute of Metals and Materials

      Volume: 85 Issue: 1 Pages: 30-39

    • DOI

      10.2320/jinstmet.JD202005

    • NAID

      130007959964

    • ISSN
      0021-4876, 1880-6880, 2433-7501
    • Year and Date
      2021-01-01
    • Related Report
      2020 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] Mechanical response of dislocation interaction with grain boundary in ultrafine-grained interstitial-free steel2021

    • Author(s)
      Li Hongxing、Gao Si、Tomota Yo、Ii Seiichiro、Tsuji Nobuhiro、Ohmura Takahito
    • Journal Title

      Acta Materialia

      Volume: 206 Pages: 116621-116621

    • DOI

      10.1016/j.actamat.2021.116621

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Pop-In Phenomenon as a Fundamental Plasticity Probed by Nanoindentation Technique2021

    • Author(s)
      Ohmura Takahito、Wakeda Masato
    • Journal Title

      Materials

      Volume: 14 Issue: 8 Pages: 1879-1879

    • DOI

      10.3390/ma14081879

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] Unique universal scaling in nanoindentation pop-ins2020

    • Author(s)
      Sato Yuji、Shinzato Shuhei、Ohmura Takahito、Hatano Takahiro、Ogata Shigenobu
    • Journal Title

      Nature Communications

      Volume: 11 Issue: 1 Pages: 4177-4177

    • DOI

      10.1038/s41467-020-17918-7

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] Continuous and discontinuous yielding behaviors in ferrite-cementite steels2020

    • Author(s)
      Wang Yanxu、Tomota Yo、Ohmura Takahito、Gong Wu、Harjo Stefanus、Tanaka Masahiko
    • Journal Title

      Acta Materialia

      Volume: 196 Pages: 565-575

    • DOI

      10.1016/j.actamat.2020.07.017

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Effect of Solute Carbon on Onset of Local Plastic Deformation in BCC Iron2020

    • Author(s)
      Nakano Katsuya、Ohmura Takahito
    • Journal Title

      Tetsu-to-Hagane

      Volume: 106 Issue: 6 Pages: 372-381

    • DOI

      10.2355/tetsutohagane.TETSU-2019-095

    • NAID

      130007849757

    • ISSN
      0021-1575, 1883-2954
    • Related Report
      2020 Annual Research Report
    • Peer Reviewed
  • [Journal Article] The effect of boundary or interface on stress-induced martensitic transformation in a Fe-Ni alloy2020

    • Author(s)
      Man Tinghui、Ohmura Takahito、Tomota Yo
    • Journal Title

      Materials Today Communications

      Volume: 23 Pages: 100896-100896

    • DOI

      10.1016/j.mtcomm.2020.100896

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Atomistic prediction of the temperature- and loading-rate-dependent first pop-in load in nanoindentation2019

    • Author(s)
      Sato Yuji、Shinzato Shuhei、Ohmura Takahito、Ogata Shigenobu
    • Journal Title

      International Journal of Plasticity

      Volume: 121 Pages: 280-292

    • DOI

      10.1016/j.ijplas.2019.06.012

    • Related Report
      2019 Annual Research Report
    • Peer Reviewed
  • [Journal Article] In-situ transmission electron microscopy investigation of compressive deformation in interphase-precipitated carbide-strengthened α-iron single-crystal nanopillars2019

    • Author(s)
      Gao, M.-Y., Tsai, S.-P., Yang, J.-R., Chang, Y.-L., Ohmura, T., Chen, C.-Y., Wang, S.-H., Wang, Y.-T., Huang, C.-Y.
    • Journal Title

      Mater. Sci. Eng.

      Volume: 746 Pages: 406-415

    • DOI

      10.1016/j.msea.2018.12.055

    • Related Report
      2019 Annual Research Report 2018 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Presentation] Characterization of Dislocation Motions in Metallic Materials by TEM In-situ Straining and Nanoindentation2020

    • Author(s)
      T. Ohmura
    • Organizer
      4th Symp. for The Core Research Cluster for Materials Science
    • Related Report
      2020 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] NANO-MECHANICAL BEHAVIOR OF BCC IRONS CHARACTERIZED THROUGH NANOINDENTATION AND TEM IN-SITU STRAINING2019

    • Author(s)
      T. Ohmura
    • Organizer
      Nanomechanical Testing in Materials Research and Development VII
    • Related Report
      2019 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] “Nano-mechanical characterization for bcc metals through nanoindentation and TEM in-situ straining2019

    • Author(s)
      T. Ohmura
    • Organizer
      NANO KOREA 2019
    • Related Report
      2019 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] Collective motion of dislocation associated with local plasticity initiation and subsequent behavior in bcc metals2018

    • Author(s)
      T. Ohmura
    • Organizer
      MS&T18
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research / Invited

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Published: 2018-04-23   Modified: 2022-08-22  

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