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$Zr_{55}Cu_{30}Al_{10}Ni_{5}$ 벌크 유리상 금속 변형거동의 변형률속도 의존성 (Strain Rate Dependency of Deformation Behavior in $Zr_{55}Cu_{30}Al_{10}Ni_{5}$ Bulk Metallic Glass)

  • 신형섭;정영진;고동균;오상엽
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 추계학술대회
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    • pp.1145-1150
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    • 2003
  • Zr-based bulk metallic glasses have a significant mechanical properties such as high strength and elastic strain limit, and a good processing ability due to the deformation behavior such as superplasticity under supercooled liquid region. Recently, many researches on the determination of optimum working condition in various bulk metallic glasses have been carried out. In this study, the deformation behavior and forming conditions of $Zr_{55}Cu_{30}Al_{10}Ni_{5}$ bulk metallic glass were investigated under three different strain rates and at various temperatures between 627K and 727K. The glass transition temperature, crystallization temperature and supercooled liquid region of $Zr_{55}Cu_{30}Al_{10}Ni_{5}$ bulk metallic glass are 680K, 762K and 82K, respectively.

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고온에서 $Zr_{55}Al_{10}Ni_5Cu_{30}$ 벌크 유리금속의 변형거동 (Deformation Behavior of a $Zr_{55}Al_{10}Ni_5Cu_{30}$ Bulk Metallic Glass at High Temperatures)

  • 정영진;김기현;오상엽;신형섭
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.342-347
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    • 2004
  • The deformation behavior of a $Zr_{55}Al_{10}Ni_5Cu_{30}$ bulk metallic glass under tensile loading at different range of strain rates and temperatures between 680 K and 740 K were investigated. The variation in the deformation behavior of $Zr_{55}Al_{10}Ni_5Cu_{30}$ bulk metallic glass which resulted from the crystallization induced during testing was reported. The$Zr_{55}Al_{10}Ni_5Cu_{30}$ bulk metallic glass has showed either homogeneous or inhomogeneous deformation depending on test condition. It exhibited a maximum elongation of about 560 % at the condition of $407^{\circ}C{\times}\;10^{-4}/s$. The flow behavior exhibited three different types and the flow stress became lower at higher temperatures and lower strain rates. The increase of the time elapsed during heating resulted in the partial crystallization of bulk metallic glass phase and eventually strain hardening and brittle fracture.

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