• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 춘계학술대회 논문집
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• pp.369-369
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• 2009

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 추계학술대회 논문집
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• pp.311-311
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• 2008

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 추계학술대회 논문집
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• pp.412-412
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• 2009

• 대한금속재료학회지
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• 제48권8호
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• pp.699-704
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• 2010

We investigated the cryogenic temperature plasticity of a bulk amorphous alloy. Experiments showed that as temperature decreases, the plasticity of the alloy increases, such that the alloy exhibited ~20% of plastic strain when tested at $-196^{\circ}C$. This enhancement in the plasticity at cryogenic temperatures was associated with the formation of abundant shear bands distributed uniformly over the entire surface of the sample. Nonetheless, the serrations, the characteristic feature of the plastic deformation of amorphous alloys, were unclear at $-196^{\circ}C$. In this study, both the enhanced plasticity and the unclear serrations exhibited by the amorphous alloy at cryogenic temperatures were clarified by exploring shear banding behaviors in the context of the velocity and the viscosity of a propagating shear band.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 추계학술대회 논문집
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• pp.462-462
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• 2009

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 춘계학술대회 논문집
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• pp.512-512
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• 2008

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 춘계학술대회 논문집
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• pp.107-110
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• 2007

It has been reported that the permanent strain could happen during recrystallization and grain growth even under the externally applied stress which is much lower than yield stress. In this study, we performed dilatometry experiments under the various compressive stresses and measured the amount of recrystallization and grain growth induced permanent strain. A new constitutive equation based on the concept of boundary migration induced plasticity was suggested to describe the recrystallization and grain growth induced plasticity. This equation was verified by comparing the calculated values with dilatometric experimental data under the various compressive stresses.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 추계학술대회 논문집
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• pp.453-453
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• 2009

• 대한금속재료학회지
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• 제47권11호
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• pp.773-785
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• 2009

Studies of a number of Cu-Zr amorphous alloys have demonstrated that those exhibiting greater plastic strain during homogeneous deformation at room temperature show lower global plasticity associated with inhomogeneous deformation in a typical compression test. Using a combination of experiments and molecular dynamics simulations, we clarify this seeming paradox between the homogeneous and inhomogeneous deformation by exploring the microstructural aspects in view of the structural disordering, disorder-induced softening, and shear localization and relate these findings to the global plasticity of bulk amorphous alloys. Additional analyses were conducted to derive a simple structural parameter that allows the prediction of the global plasticity of bulk amorphous alloys.

• 한국결정성장학회지
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• 제17권5호
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• pp.223-230
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• 2007

화력발전소에서 발생하는 석탄 바닥재를 효과적으로 재활용하기 위해 여러 가지 폐기물을 함유한 점토소지와 바닥재를 첨가한 점토소지의 가소성 지수를 Atterberg 한계를 이용하여 측정하였다. 그리고 압출 성형을 통하여 가소성 지수가 실제 성형공정에 적용 가능한지를 확인하였다. 수분, 바닥재 함유량, 그리고 석분과 하수오니의 첨가 조성을 달리해 성형이 가능한 조성을 찾았으며, 골재를 만들어 가소성에 따라 성형체의 물성이 어떻게 바뀌는지 조사하였다. 가소성 지수로 압출성형이 가능한 조성을 찾을 수 있으며, 실제로도 압출 성형이 가능한 것을 확인할 수 있었다. 그리고 가소성과 골재 성형체의 물성을 관찰한 결과 첨가 폐기물의 종류에 따라 차이는 있었지만 일반적으로 가소성 지수가 낮아지면, 소지의 비중은 낮아졌으며, 흡수율은 증가하는 경향이 있음을 알 수 있었다.