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: Chapter in Book/Report/Conference proceedingConference contribution

    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.

    本文言語英語
    ホスト出版物のタイトルTHERMEC 2011
    出版社Trans Tech Publications Ltd
    ページ1841-1846
    ページ数6
    ISBN(印刷版)9783037853030
    DOI
    出版ステータス出版済み - 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(印刷版)0255-5476
    ISSN(電子版)1662-9752

    その他

    その他7th International Conference on Processing and Manufacturing of Advanced Materials, THERMEC'2011
    国/地域カナダ
    CityQuebec City, QC
    Period8/1/118/5/11

    All Science Journal Classification (ASJC) codes

    • 材料科学(全般)
    • 凝縮系物理学
    • 材料力学
    • 機械工学

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