金属ガラスのナノ準結晶化メカニズムの解明とその応用

• Project/Area Number: 15074203
• Research Category: Grant-in-Aid for Scientific Research on Priority Areas
• Allocation Type: Single-year Grants
• Review Section: Science and Engineering
• Research Institution: Tohoku University
• Principal Investigator: 才田 淳治 Tohoku University, 学際科学国際高等研究センター, 准教授 (20359540)
• Co-Investigator(Kenkyū-buntansha): LOUZGUINE D.V. (LOUZGUINE D. V. / LOUZGUINR D.V.) 東北大学, 金属材料研究所, 准教授 (60302212)
• Project Period (FY): 2003 – 2007
• Project Status: Completed (Fiscal Year 2007)
• Budget Amount: ¥40,600,000 (Direct Cost: ¥40,600,000); Fiscal Year 2007: ¥2,100,000 (Direct Cost: ¥2,100,000); Fiscal Year 2006: ¥3,200,000 (Direct Cost: ¥3,200,000); Fiscal Year 2005: ¥6,100,000 (Direct Cost: ¥6,100,000); Fiscal Year 2004: ¥13,800,000 (Direct Cost: ¥13,800,000); Fiscal Year 2003: ¥15,400,000 (Direct Cost: ¥15,400,000)
• Keywords: 金属ガラス / ナノ準結晶 / 塑性変形 / 二十面体原子配列 / 局所構造 / 微細構造解析 / 過冷却液体 / 動的構造変化 / 相変態 / 変形

Research Abstract

金属ガラスからのナノ準結晶析出機構として二十面体局所構造を考察し、実際にZr_<70>Cu_<30>やZr_<70>Al_<10>Ni_<20>金属ガラスと初晶ナノ準結晶の析出状態の局所環境に大きな違いがないことを明らかにしてきた。これらの研究で得られた知見をもとに、急冷過程で容易にナノ準結晶が析出するZr_<80>Pt_<20>非晶質合金の局所環境が、二十面体局所配列とZr5Pt3構造に類似の環境で構成されていることを見出した。以上の結果は、過冷却液体の安定性におよぼす二十面体局所構造や特定元素周囲の再配列の要否等、ガラスの安定性に係わる重要な知見を総合的に評価することができた成果である。
二十面体局所構造が安定に生成すると考えられるZr_<65>Al_<7.5>Ni_<10>(Cu,Pd)_<17.5>金属ガラスの核生成挙動を制御することで、これまで得られなかった組成範囲でバルク状ガラス合金の作製に成功した。また、これら合金の圧縮変形挙動を調べた結果、一般のバルク金属ガラスよりも優れた塑性変形能を示すことを明らかにした。このような大きな塑性変形能を発現するメカニズムとして、圧縮変形破面付近の透過電子顕微鏡(TEM)によるナノスケール解析の結果、変形帯の移動にともなって動的な微細結晶析出が起きることを確認した。さらに、このようなナノスケールの動的構造変化が、安定な局所構造の形成によって起こる局所不均質構造ならびにそれらとも密接に関連する過冷却液体の安定性に依存して発現するというメカニズムについても考察した。

Research Products

• [Journal Article] Local structure in Zr-based metallic glasses (2007)
  • Author(s): J. Saida, et. al.
  • Journal Title: Materials Transactions 48 Pages: 1703-1707
  • Peer Reviewed
• [Journal Article] Deformation-induced nanoscale dynamic transformation studies in Zr-Al-Ni-Pd and Zr-Al-Ni-Cu bulk metallic glasses (2007)
  • Author(s): J. Saida, et. al.
  • Journal Title: Materials Transactions 48 Pages: 1327-1335
  • NAID: 10019486426
  • Peer Reviewed
• [Journal Article] Local structure characterization in quasicrystal-forming Zr80Pt20 binary amorphous alloy (2007)
  • Author(s): J. Saida, et. al.
  • Journal Title: Applied Physics Letters 91
  • NAID: 120002338384
  • Peer Reviewed
• [Journal Article] Correlation between local structure and stability of supercooled liquid state in Zr-based metallic glasses (2007)
  • Author(s): J.Saida et al.
  • Journal Title: Materials Science an Engineering A 449-451 Pages: 90-94
• [Journal Article] Effect of Al on the local structure and stability of Zr-based metallic glasses (2007)
  • Author(s): J.Saida et al.
  • Journal Title: Journal of Alloys and Compounds 434-435 Pages: 135-137
• [Journal Article] Evidence for effect of hydrostatic pressure during casting on glass-forming ability in Zr_<65>Al_<7.5>Ni_<10>Cu_<17.5-x>Pd_x (x=0-17.5) alloys (2007)
  • Author(s): A.D.H.Setyawan et al.
  • Journal Title: Materials Science an Engineering A 449-451 Pages: 903-906
• [Journal Article] Thermal conductivity of an alloy in relation to the observed cooling rate and glass-forming ability (2007)
  • Author(s): D.V.Louzguine et al.
  • Journal Title: Philosophical Magazine 87 Pages: 1845-1854
• [Journal Article] Fragility and thermal stability of Pt- and Pd-based bulk metallic glass forming liquids and their correlation with deformability (2006)
  • Author(s): H.Kato et al.
  • Journal Title: Scripta Materialia 54 Pages: 2023-2027
• [Journal Article] Structural instability of metallic glasses under radio-frequency-ultrasonic perturbation and its correlation with glass-to -crystal transition of less-stable metallic glasses (2006)
  • Author(s): T.Ichitsubo et al.
  • Journal Title: Journal of Chemical Physics 125 Pages: 154502-154502
• [Journal Article] Reduced electronegativity difference as a factor leading to the formation of Al-based glassy alloys with a large supercooled liquid region of 50 K (2006)
  • Author(s): D.V.Louzguine-Luzgin et al.
  • Journal Title: Applied Physics Letters 88
• [Journal Article] Comparative study of local structure in Zr_<70>Al_<10>Ni_<20> and quasicrystal-forming Zr_<70>Al_9Ni_<20>Pd_1 metallic gasses (2005)
  • Author(s): J.Saida et al.
  • Journal Title: Philosophical Magazine Letters 85 Pages: 135-144
• [Journal Article] Characterization and properties of nanocrystal-forming Zr-based bulk metallic glasses (2005)
  • Author(s): J.Saida et al.
  • Journal Title: Review of Advanced Materials Science 10 Pages: 34-38
• [Journal Article] Nanoscale multistep shear band formation by deformation-induced nanocrystallization in Zr-Al-Ni-Pd bulk metallic glass (2005)
  • Author(s): J.Saida et al.
  • Journal Title: Applied Physics Letters 87
  • NAID: 120002338383
• [Journal Article] Microstructure of fragile metallic glass interred from ultrasound-accelerated crystallization in Pd-based metallic glass (2005)
  • Author(s): T.Ichitsubo et al.
  • Journal Title: Physical Review Letters 95
• [Journal Article] Composition and structure of Cu-base nanoicosahedral phase in Cu-Zr-Ti-Pd alloy (2005)
  • Author(s): D.V.Louzguine-Luzgin et al.
  • Journal Title: Applied Physics Letters 87
• [Journal Article] Primary precipitation of icosahedral quasicrystal with rearrangement of constitutional elements in Zr_<65>Al_<7.5>Cu_<27.5>gassy alloy with low oxygen impurity (2005)
  • Author(s): J.Saida et al.
  • Journal Title: Journal of Materials Research 20 Pages: 303-306
• [Journal Article] Novel nanostructure and deformation behavior in rapidly quenched Cu-(Zr or Hf)-Ti alloys (2005)
  • Author(s): J.Saida et al.
  • Journal Title: Advanced Engineering Materials 7 Pages: 39-43
• [Journal Article] Formation ranges of icosahedral, amorphous and crystalline phases in rapidly solidified Ti-Zr-Hf-Ni alloys (2005)
  • Author(s): Chen et al.
  • Journal Title: Acta Materialia 53 Pages: 759-764
• [Journal Article] In-situ x-ray diffraction and calorimetric studies of devitrification process in Cu-based bulk glassy alloys (2005)
  • Author(s): D.V.Louzguine et al.
  • Journal Title: Applied Physics Letters 86
• [Journal Article] Influence of hydrostatic pressure during casting and Pd content on as-cast phase in Zr-Al-Ni-Cu-Pd bulk alloys (2004)
  • Author(s): H.Kato et al.
  • Journal Title: Applied Physics Letters 85 Pages: 2205-2207
• [Journal Article] Devitrification of Ni-based glassy alloys containing noble metals in relation with the supercooled liquid region (2004)
  • Author(s): D.V.Louzguine et al.
  • Journal Title: Journal of Non-Crystalline Solids 337 Pages: 161-165
• [Presentation] Nano structure controlling in Zr-based metallic glasses using icosahedral local structure (2007)
  • Author(s): J. Saida, et. al.
  • Organizer: 14th International Symposium on Metastable and Nano-Materials
  • Place of Presentation: Corfu, Greece
  • Year and Date: 2007-08-27
• [Remarks]
  • URL: http://www.cir.tohoku.ac.jp/j/2research/prof.htm
• [Patent(Industrial Property Rights)] 非晶質合金の製造方法 (2004)
  • Inventor(s): 加藤 秀実, 才田 淳治, 井上 明久
  • Industrial Property Rights Holder: 東北大学
  • Industrial Property Number: 2004-253092
  • Filing Date: 2004-08-31
• [Publications] J.Z.Jiang et al.: "Evidence of icosahedral short-range order in Zr70Cu30 and Zr70Cu29Pd1 metallic glasses"Applied Physics Letters. 83. 3924-3926 (2003)
• [Publications] J.Saida et al.: "Nanoquasicrystallization in metallic glasses"Material Transactions. 44. 1971-1977 (2003)
• [Publications] D.V.Louzguine et al.: "Transformation from glassy + β-Zr to glassy + icosahedral structure in Zr-based alloy"Scripta Materialia. 50. 973-976 (2004)
• [Publications] J.Saida et al.: "Microstructure of tensile fracture in nano icosahedral quasicrystal dispersed Zr80Pt20 amorphous alloy"Scripta Materialia. 50. 1297-1301 (2004)