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Precipitation Mechanism of coherent precipitates using HAADF-STEM

Research Project

Project/Area Number 13650711
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field Physical properties of metals
Research InstitutionOsaka Prefecture University (2002)
Tohoku University (2001)

Principal Investigator

KONNO Toyohiko  Osaka Pref. Univ., Dept. Materials Science, Professor, 大学院・工学研究科, 教授 (90260447)

Co-Investigator(Kenkyū-buntansha) HIRAGA Kenji  Tohoku Univ., Inst. for Materials Research, Professor, 金属材料研究所, 教授 (30005912)
Project Period (FY) 2001 – 2002
Project Status Completed (Fiscal Year 2002)
Budget Amount *help
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2002: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 2001: ¥1,700,000 (Direct Cost: ¥1,700,000)
KeywordsAged alloys / Transmission Electron Microscopy / Scanning TEM / coherent precipitation / Al-Cu alloy / Al-Ag alloy / Ae-Li-Cu alloy / GP zone / 効析出型合金
Research Abstract

We have examined Guinier-Preston (GP) zones in aged Al-Cu alloys using the atomic resolution high-angle annular detector dark-field scanning transmission electron microscopy (HAADF-STEM), together with conventional high-resolution transmission electron microscopy (HRTEM).
[1] Al-Cu system: We have found the GP-I zones consisting of two Cu layers, in addition to the commonly-known monolayered GP-I. The structure of GP-II, in which Cu monolayers are separated by three Al layers, was identified; whereas a variant of GP-II does exist, e.g., double Cu layers separated by single Al layer. In addition, in the GP-I stage, we have occasionally found Cu monolayers separated by three Al layers, which can be the incipient stage of GP-II. These results are in general agreement with previous observations by small angle scattering and field-ion microscopy. Also, our results indicate that the GP-II zone can act as a nucleation site for the θ' phase.
[2] Al-Li-Cu system: The δ' phase (Al_3Li, Ll_2 structure was found to exist in the as-quenched specimen containing 2.4wt%-Li, whereas no precipitation was observed in the as-quenched specimen with 1.6wt%-Li. After aging at 100℃ for 3hr, GP-I zones nucleated homogeneously in both specimens; but no δ' phase was detected in the 1.6wt%-Li alloy at that stage. As the aging proceeds, the δ' phase nucleates and grows on the GP-I zones. The composite structure, in which the GP-I zone is flanked by a pair of lenticular δ' particles, is stable in 180-200℃. The facing lenticular δ' particles on a GP-I zone were systematically found to be anti-phase with respect to each other.

Report

(3 results)
  • 2002 Annual Research Report   Final Research Report Summary
  • 2001 Annual Research Report
  • Research Products

    (17 results)

All Other

All Publications (17 results)

  • [Publications] Toyohiko.J.Konno, Masahiro Kawasaki, Kenji Hiraga: "Direct imaging of Guinier-Preston zones by high-angle annular detector dark-field scanning transmission electron microscopy"Journal of Electron Microscopy. 50・2. 105-111 (2001)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] Toyohiko.J.Konno, Masahiro Kawasaki, Kenji Hiraga: "Guinier-Preston (GP) zone revisited : Atomic level observation by HAADF-TEM technique"Scripta Meterialia. 44. 2303-2307 (2001)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] Toyohiko.J.Konno, Masahiro Kawasaki, Kenji Hiraga: "Guinier-Preston zone observed by by high-angle detector dark-field scanning transmission electron microscopy"Philosophical Magazine B. 81・11. 1713-1724 (2001)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] 今野 豊彦, 川崎正博, 平賀賢二: "散乱された電子が結ぶ像"バウンダリー. 17・6. 17-21 (2001)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] Ritsuko Yoshimura, Toyohiko.J.Konno: "Transmission electron microscopy study of the early stage of precipitates in aged Al-Li-Cu alloys"Acta Materialia. (in press). (2003)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] Ritsuko Yoshimura, Toyohiko.J.Konno: "Transmission electron microscopy study of the evolution of precipitates in aged Al-Li-Cu alloys : The θ' and T1 phases"Acta Materialia. (in press). (2003)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] Toyohiko J. Konno, Masahiro Kawasaki, Kenji Hiraga: "Direct imaging of Guinier-Preston zones by high-angle annular detector dark-field scanning transmission electron microscopy"Journal of Electron Microscopy. 50. 105-111 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] Toyohiko J. Konno, Masahiro Kawasaki, Kenji Hiraga: "Guinier-Preston (GP) zone revisited: Atomic level observation by HAAPF-TEM technique"Scripta Materialia. 44. 2303-2307 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] Toyohiko J. Konno, Masahiro Kawasaki, Kenji Hiraga: "Guinier-Preston zones observed by by high-angle annular detector dark-field scanning transmission electron microscopy"Philosophical Magazine B. 81. 1713-1734 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] Ritsuko, Yoshimura, Toyohiko J. Konno, Eiji Abe, Kenji Hiraga: "Transmission electron microscopy study of the early stage of precipitates in aged Al-Li-Cu alloys"Acta Materialia. in press. (2003)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] Ritsuko Yoshimura, Toyohiko J. Konno, Eiji Abe, Kenji Hiraga: "Transmission electron microscopy study of the evolution of precipitates in aged Al-Li-Cu alloys: The θ' and T1 phases"Acta Materialia. in press. (2003)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] Ritsuko Yoshimura Toyohiko.J.Konno: "Transmission electron microscopy study of the early stage of precipitates in aged Al-Li-Cu alloys"Acta Materialia. (in press). (2003)

    • Related Report
      2002 Annual Research Report
  • [Publications] Ritsuko Yoshimura Toyohiko.J.Konno: "Transmission electron microscopy study of the evolution of precipitates in aged al-Li-Cu alloys : The θ' and T1 phases"Acta Materialia. (in press). (2003)

    • Related Report
      2002 Annual Research Report
  • [Publications] Toyohiko.J.Konno: "Direct imaging of Guinier-Preston Zones by high-angle annular detector dark-field scanning transmission electron microscopy"Journal of Electron Microscopy. 50・2. 105-111 (2001)

    • Related Report
      2001 Annual Research Report
  • [Publications] Toyohiko.J.Konno: "Guinier-Preston (GP) Zone revisited : Atomic level observation by HAADF-TEM technique"Scripta Materialia. 44. 2303-2307 (2001)

    • Related Report
      2001 Annual Research Report
  • [Publications] Toyohiko.J.Konno: "Guinier-Preston zones observed by by high-angle annular detector dark-field scanning transmission electron microscopy"Philosophical Magazine B. 81・11. 1713-1724 (2001)

    • Related Report
      2001 Annual Research Report
  • [Publications] 今野 豊彦: "散乱された電子が結ぶ像"バウンダリー. 17・6. 17-21 (2001)

    • Related Report
      2001 Annual Research Report

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Published: 2001-04-01   Modified: 2016-04-21  

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