Open Access

ABSTRACT

Influences of Nano-sized Crystalline Particles on the Mechanical Properties of Metallic Glass-- A Molecular Dynamics Study

R. Matsumoto¹, N. Miyazaki¹, M. Nakagaki²

1 Department of Mechanical Engineering and Science, Graduate School of Engineering, Kyoto University
2 Trustee, Kyushu Institute of Technology

The International Conference on Computational & Experimental Engineering and Sciences 2007, 4(4), 223-230. https://doi.org/10.3970/icces.2007.004.223

Abstract

The mechanical properties of amorphous metals and metallic glasses are remarkably changed by precipitated crystalline particles. In this paper, the effects of crystal particle size and volume fraction on the flow stress of the metallic glass are evaluated by molecular dynamics simulations. The investigated volume fraction ranges from 0% (metallic glass) to 100% (nanocrystalline metal), and the average particle diameter ranges from 1nm to 12nm. It is revealed that the dispersed particle effects on the flow stress are very small in the entire volume fraction range when the average particle diameter is smaller than 3 nm, and the flow stress is intensified as the particle size increases until about 6 nm. For a larger particle size (d>6 nm), the flow stress is not influenced by the particle size, when the crystal volume fraction is lower than 60%, and the particle size effects appear gradually for the higher crystal volume fraction (d>60%). It is shown that this phenomenon is caused by the increase of the fraction of grain boundary to the entire interface.

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