日本金属学会誌

J. Japan Inst. Met. Mater, Vol. 78, No. 1 (2014),
pp. 45-51

Influence of Competition between Intragranular Dislocation Nucleation and Intergranular Slip Transfer on Mechanical Properties of Ultrafine-Grained Metals

Tomohito Tsuru1,2, Yoshiteru Aoyagi3, Yoshiyuki Kaji1 and Tomotsugu Shimokawa4

1Nuclear Science and Engineering Directorate, Japan Atomic Energy Agency, Tokai-mura, Ibaraki 319-1195
2Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
3Graduate School of Engineering, Tohoku University, Sendai 980-8579
4School of Mechanical Engineering, College of Science and Engineering, Kanazawa University, Kanazawa 920-1192

Abstract:

Huge-scale atomistic simulations of shear deformation tests to the aluminum polycrystalline thin film containing the Frank-Read source are performed to elucidate the relationship between the inter- and intragranular plastic deformation processes and the mechanical properties of ultrafine-grained metals. Two-types of polycrystalline models, which consist of several grain boundaries reproducing easy and hard slip transfer, respectively, are prepared to investigate the effect of grain boundary on flow stress. While the first plastic deformation occurs by the dislocation bow-out motion within the grain region for both models, the subsequent plastic deformation is strongly influenced by the resistance of the slip transfer by dislocation transmission through grain boundaries. The influence of the competition between the intragranular dislocation nucleation and intergranular slip transfer on the material strength is considered. The nanostructured material's strength depending on local defect structures associated with grain size and dislocation source length is assessed quantitatively. [doi:10.2320/jinstmet.J2013039]


(Received 2013/7/29)

Keywords:

intragranular dislocation nucleation, intergranular slip transfer, bulk nanostructured metals, ultra-fine grained metals, grain boundary, dislocation source, mechanical property, atomistic simulation


PDF(Free)PDF (Free)     Table of ContentsTable of Contents

Please do not copy without permission.