Effect of grain boundaries on fracture toughness in ultrafine-grained metals by atomic-scale computational experiments

Tomotsugu Shimokawa, Masaki Tanaka, Kenji Higashida

研究成果: 著書/レポートタイプへの貢献会議での発言

抄録

In order to investigate roles of grain boundaries on the improved fracture toughness in ultrafine-grained metals, interactions between crack tips, dislocations, and disclination dipoles at grain boundaries are performed to aluminium bicrystal models containing a crack and <112> tilt grain boundaries using molecular dynamics simulations. A proposed mechanism to express the improved fracture toughness in ultrafine-grained metals is the disclination shielding effect on the crack tip mechanical field. The disclination shielding can be activated when a transition of dislocation sources from crack tips to grain boundaries and a transition of the grain boundary structure into a neighbouring energetically stable boundary by emitting dislocations from the grain boundary occur. The disclination shielding effect becomes large as dislocations are continuously emitted from the grain boundary without dislocation emissions from crack tips. This mechanism can further shield the mechanical field around the crack tip and obtain the plastic deformation by dislocation emissions from grain boundaries, hence it can be expected that the disclination shielding effect can improve the fracture toughness in ultrafine-grained metals.

元の言語英語
ホスト出版物のタイトルTHERMEC 2011
ページ1841-1846
ページ数6
DOI
出版物ステータス出版済み - 1 30 2012
イベント7th International Conference on Processing and Manufacturing of Advanced Materials, THERMEC'2011 - Quebec City, QC, カナダ
継続期間: 8 1 20118 5 2011

出版物シリーズ

名前Materials Science Forum
706-709
ISSN(印刷物)0255-5476

その他

その他7th International Conference on Processing and Manufacturing of Advanced Materials, THERMEC'2011
カナダ
Quebec City, QC
期間8/1/118/5/11

Fingerprint

fracture strength
Fracture toughness
Grain boundaries
grain boundaries
Metals
Dislocations (crystals)
crack tips
Crack tips
Shielding
metals
shielding
Experiments
Bicrystals
bicrystals
Ultrafine
Aluminum
plastic deformation
Molecular dynamics
Plastic deformation
cracks

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

これを引用

Effect of grain boundaries on fracture toughness in ultrafine-grained metals by atomic-scale computational experiments. / Shimokawa, Tomotsugu; Tanaka, Masaki; Higashida, Kenji.

THERMEC 2011. 2012. p. 1841-1846 (Materials Science Forum; 巻 706-709).

研究成果: 著書/レポートタイプへの貢献会議での発言

Shimokawa, T, Tanaka, M & Higashida, K 2012, Effect of grain boundaries on fracture toughness in ultrafine-grained metals by atomic-scale computational experiments. : THERMEC 2011. Materials Science Forum, 巻. 706-709, pp. 1841-1846, 7th International Conference on Processing and Manufacturing of Advanced Materials, THERMEC'2011, Quebec City, QC, カナダ, 8/1/11. https://doi.org/10.4028/www.scientific.net/MSF.706-709.1841
Shimokawa, Tomotsugu ; Tanaka, Masaki ; Higashida, Kenji. / Effect of grain boundaries on fracture toughness in ultrafine-grained metals by atomic-scale computational experiments. THERMEC 2011. 2012. pp. 1841-1846 (Materials Science Forum).
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