• Title/Summary/Keyword: elastostatic compression

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Free Volume Formation in Amorphous Alloys: a Molecular Dynamics Study (비정질 합금의 자유부피 생성기구: 분자동력학적 고찰)

  • Lee, Chang-Myeon;Park, Kyoung-Won;Lee, Byeong-Joo;Shim, Jae-Hyeok;Lee, Jae-Hoon;Lee, Jae-Chul
    • Korean Journal of Metals and Materials
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    • v.46 no.11
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    • pp.701-707
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    • 2008
  • This study examined the creation mechanism of free volume during homogeneous deformation induced by the elastostatic compression at room temperature. Experiments demonstrated that amorphous alloys subjected to the elastostatic compression underwent structural disordering, during which densely packed polyhedra breakdown to form new, loosely packed ones, resulting in the creation of excess free volume. A combination of experiments and molecular dynamics simulations are used to explore fundamental issues on how free volume is created during elastostatic compression.

A Study on the Methodology of the Plasticity Enhancement of Amorphous Alloys (비정질 합금의 소성 증가 방법에 대한 연구)

  • Park, K.W.;Lee, C.M.;Lee, K.B.;Lee, J.C.
    • Transactions of Materials Processing
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    • v.17 no.7
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    • pp.486-490
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    • 2008
  • This study demonstrates that preloading via the elastostatic compression imposed on amorphous alloys at room temperature induces homogeneous plastic strain associated with structural disordering. This structural disordering causes disorder, which at room temperature creates excess free volume and in turn enhances the plasticity. In this study, we investigated the effects of various parameters, such as stress level, flow rate and preloading time, on the degree of the structural disordering at room temperature. On the basis of the present findings, we proposed a method of enhancing the plasticity of amorphous alloys.

Energy Absorption Capability of Amorphous Alloys During Homogeneous Deformation (균일변형시 비정질 합금의 에너지 흡수력 평가)

  • Park, Kyoung-Won;Lee, Chang-Myeon;Lee, Hong-Gi;Lee, Jae-Hoon;Lee, Jae-Chul
    • Korean Journal of Metals and Materials
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    • v.46 no.9
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    • pp.572-576
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    • 2008
  • Elastostatic compression tests were carried out on amorphous alloys to evaluate their energy absorption capability during homogeneous deformation at room temperature. Experiments demonstrated that a compressive stress below the global yield imposed on amorphous alloys for extended periods causes homogeneous plastic strain associated with the irreversible structural disordering. During the disordering process, free volume was created, dissipating the externally applied strain energy and the rate of creation was found to converge to a saturated value. We evaluated the capability of energy absorption of amorphous alloys during homogeneous deformation using recent theories on the evolution of the structural state.