Materials Transactions Online

Materials Transactions, Vol.51 No.09 (2010) pp.1504-1509
© 2010 The Japan Institute of Metals

Enhancement of Plasticity of Highly Density-Fluctuated Cu-Zr Amorphous Alloy

Junyoung Park1, Yoji Shibutani2 and Masato Wakeda3

1School of Mechanical Engineering, Kumoh National Institute of Technology, Gumi, Gyeongbuk 730-701, Korea
2Department of Mechanical Engineering, Osaka University, Osaka 565-0871, Japan
3Department of Mechanical Engineering, Iwate University, Morioka 020-8550, Japan

This study explores the plastic deformability of highly density-fluctuated states due to the different thermal quenching process of the binary amorphous metals, Zr67Cu33, with embedded nanocrystals, Zr2Cu. To know the effect of local structural fluctuation, we prepare 5 computational models with Zr2Cu-nanocrystals that undergo rapid heat up and cool down. The region of nanocrystals is corresponding to the dense area because the intrinsic density of crystal is greater than that of amorphous structure. Due to the distribution of nanocrystals, the artificially constructed models have highly density-fluctuated structures (called ``structural-inhomogeneity''). Strain localization during plastic deformation is much retarded at structural-inhomogeneous model in tensile loading. We found that structural-inhomogeneity promotes more homogenous deformation (call ``deformable-homogeneity'', that is, retarded strain localization) even in globally recognized elastic region, while structural-homogeneity (almost close to pure amorphous structure) makes catastrophic inhomogeneous deformation (catastrophic shear band).

(Received 2010/4/22; Accepted 2010/6/28; Published 2010/8/11)

Keywords: zirconium-copper binary amorphous alloy, highly density-fluctuated state, Zr2Cu-nanocrystals, shear band, molecular dynamics simulation, plane stress condition

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