Mechanical Properties and Deformation Mechanisms of Bulk Nanostructured Metals

2014 Fiscal Year Final Research Report

• Project Area: Bulk Nanostructured Metals -New Metallurgy of Novel Structural Materials
• Project/Area Number: 22102006
• Research Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
• Allocation Type: Single-year Grants
• Review Section: Science and Engineering
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: KATO Masaharu 東京工業大学, 総合理工学研究科(研究院), 教授 (50161120)
• Co-Investigator(Kenkyū-buntansha): ONAKA Susumu 東京工業大学, 総合理工学研究科, 教授 (40194576) ; TOMOTA Yo 茨城大学, 理工学研究科, 名誉教授 (90007782) ; TANAKA Masaki 九州大学, 工学研究院, 准教授 (40452809) ; KAMIKAWA Naoya 東北大学, 金属材料研究所, 助教 (30530894) ; KANEKO Yoshihisa 大阪市立大学, 工学研究科, 教授 (40283098)
• Co-Investigator(Renkei-kenkyūsha): FUJII Toshiyuki 東京工業大学, 理工学研究科, 教授 (40251665) ; MIYAJIMA Yoji 東京工業大学, 総合理工学研究科, 助教 (80506254)
• Project Period (FY): 2010-04-01 – 2015-03-31
• Keywords: バルクナノメタル / 超微細結晶粒 / 力学特性 / 結晶粒界 / 転位 / 熱活性化変形過程

Outline of Final Research Achievements

Bulk nanostructured metals (BNMs) with grain size smaller than 1 micrometer are known to be much stronger than conventional metals whose grain size is usually larger than 10 micrometers. In addition, BNMs show various characteristic mechanical properties in ductility, fracture, fatigue properties, etc.
These mechanical properties of BNMs were investigated in detail and deformation and fracture mechanisms were discussed both experimentally and theoretically. It has been found that the effects of grain boundaries on the formation and motion of dislocations play an essential role in the mechanical response of BNMs. The internal structure of BNMs was investigated by using, for example, a synchrotron radiation facility. Many new experimental results, such as the change in dislocation density during plastic deformation of a copper BNM, were obtained for the first time in the world.

Free Research Field

材料科学