Open Access

ARTICLE

Molecular-dynamics Study on Crack Growth Behavior Relevant to Crystal Nucleation in Amorphous Metal

by R. Matsumoto¹, M. Nakagaki¹, A. Nakatani², H. Kitagawa³

1 Department of Mechanical Information Engineering, Faculty of Computer Science and Systems Engineering, Kyushu Institute of Technology 680-4 Kawazu, Iizuka-City, Fukuoka 820-8502, Japan
2 Department of Adaptive Machine Systems, Graduate School of Engineering, Osaka University 2-1 Yamada-Oka, Suita-City, Osaka 565-0871, Japan
3 Department of Energy and Mechanical Engineering, Faculty of Engineering, Doshisha University, 1-3 Tatara Tsudani, Kyotanabe-City, Kyoto 610-0394, Japan

Computer Modeling in Engineering & Sciences 2005, 9(1), 75-84. https://doi.org/10.3970/cmes.2005.009.075

Abstract

In this paper, the internal structure-changes around the crack-tip and the pertinent crack growth behavior in an amorphous metal were studied by a molecular dynamics (MD) simulation. In order to perform a large scale calculation, the domain decomposition method was used for parallel calculation. The Finnis-Sinclair potential for$\alpha$-iron was used to describe the interatomic potential. Computed results show that nano-scaled crystalline phase grows around the crack-tip. The distribution of deformation zones and deformation mechanism are significantly altered. While grains are relatively small, they are not deformed, and the most amorphous-crystal interfaces have a large strain for phase transition. The emission of dislocations from the near crack-tip is observed after the crystal phase covered the crack-tip surfaces. Although CTOD obtained from MD analysis agrees to Dugdale's model very well during the amorphous state, the crack opening behavior changes remarkably after the crystallization.

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Keywords

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