• 제목/요약/키워드: Zr-Be amorphous alloy

검색결과 33건 처리시간 0.026초

나노결정형 Zr57V36Fe7 게터합금의 수소흡수특성 (Hydrogen Absorption Properties of Nanocrystalline Zr57V36Fe7 Getter alloy)

  • 박제신;서창열;김원백
    • 한국분말재료학회지
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    • 제12권6호
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    • pp.433-440
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    • 2005
  • The hydrogen sorption speed of $Zr_{57}V_{36}Fe_7$ nanocrystalline and amorphous alloys was evaluated at room temperature. Nanocrystalline alloys of $Zr_{57}V_{36}Fe_7$ were prepared by planetary ball milling. The hydrogen sorption speed of nanocrystalline alloys was higher than that of the amorphous alloy. The enhanced sorption speed of nanocrystalline alloys was explained in terms of surface oxygen stability which has been known to retard the activation of amorphous alloys. The retardation can be reduced by formation of nanocrystals, which results in the observed increase in sorption properties.

벌크 비정질 Zr-Ti-Cu-Ni-Be 합금의 고온 소성 변형 특성 (High Temperature Plastic Deformation Behaviors of the Bulk Metallic Glass Zr-Ti-Cu-Ni-Be Alloy)

  • 이광석;하태권;안상호;장영원
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2001년도 추계학술대회 논문집
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    • pp.272-276
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    • 2001
  • Multicomponent $Zr_{41.2}Ti_{13.8}Cu_{12.5}Ni_{10}Be_{22.5}$ bulk matallic glass alloy shows good bulk glass forming ability due to its high resistance to crystallization in the undercooled liquid state.1) In this study, DSC and X-ray diffractometry have been performed to confirm the amorphous structure of the master $Zr_{41.2}Ti_{13.8}Cu_{12.5}Ni_{10}Be_{22.5}$ alloy. To investigate the mechanical properties and deformation behaviors of the bulk metallic $Zr_{41.2}Ti_{13.8}Cu_{12.5}Ni_{10}Be_{22.5}$ alloy, a series of compression tests has been carried out at the temperatures ranging from $351^{\circ}C$ to $461^{\circ}C$ and at the various initial strain rates from $2{\times}10^{-4}s^{-1}\;to\;2{\times}10^{-2}s^{-1}$. There are two types of nominal stress-strain curves. The one shows linear stress-strain relationship meaning fracture at maximum stress, the other shows plastic deformation including steady-state flow. Also DSC analysis for the compressed specimens has been performed to investigate the change of thermal stability and crystallization behavior for the various test conditions.

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벌크 비정질 Zr-Ti-Cu-Ni-Be 합금의 고온 압축 변형 특성 (High Temperature Compressive Deformation Behavior of the Bulk Metallic Glass Zr-Ti-Cu-Ni-Be Alloy)

  • 이광석;하태권;안상호;장영원
    • 소성∙가공
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    • 제10권7호
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    • pp.565-572
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    • 2001
  • It is well known that a multicomponent $Zr_{4l.2}Ti_{13.8}Cu_{12.5}Ni_{10}Be_{22.5}$ bulk metallic glass alloy shows good bulk glass forming ability due to its high resistance to crystallization in the undercooled liquid state. DSC and XRD have been performed to confirm the amorphous structure of the master alloy. To investigate the mechanical properties and deformation behavior of the bulk metallic $Zr_{4l.2}Ti_{13.8}Cu_{12.5}Ni_{10}Be_{22.5}$ alloy, a series of compression tests has been carried out at the temperatures ranging from $351^{\circ}C$ to $461^{\circ}C$at the various initial strain rates from $2{\times}10^4s^1$ to $2{\times}10^2s^1$. Three types of nominal stress-strain curves have been identified such as linear stress-strain relationship meaning fracture at maximum stress, plastic deformation including stress overshoot and steady-state flow, plastic deformation without stress overshoot depending on the strain rate and test temperature. Also DSC analysis for the compressed specimens was carried out to investigate the change of structure, thermal stability and crystallization behavior for the various test conditions.

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Zr-기 벌크 아몰퍼스 금속의 충격 파괴 거동 (Impact Fracture Behaviors of Zr-Based Bulk Amorphous Metals)

  • 고동균;정영진;신형섭;오상엽
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 추계학술대회
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    • pp.1246-1251
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    • 2003
  • The fracture behaviors of Zr-based bulk amorphous metals(BAMs) having compositions of $Zr_{55}Al_{10}Ni_{5}Cu_{30}$, were investigated under impact loading and quasi-static conditions. For experiments, a newly devised instrumented impact testing apparatus and the subsize Charpy specimens were used. The influences of loading rate and the notch shape on the fracture behavior of the Zr-based BAM were examined. The Zr-based BAMs showed an elastic deformation behavior without any plastic deformation on it before fracture. Most fracture energies were absorbed in the process of the crack initiation. The maximum load and fracture absorbed energy under quasi-static condition were larger than those under impact condition. However, there existed relatively insignificant notch shape effect. Fracture surfaces under impact loading were smoother than those under quasi-static loading. The absorbed fracture energy appeared differently depending on the extent of the vein-like pattern region due to the shear bands developed at the notch tip. It can be found that the fracture energy of the Zr-Al-Ni-Cu alloy is closely related with the development of shear bands during fracture.

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$Fe_{87}Zr_{7}B_{5}Ag_{1}$ 비정질합금의 연자기 특성 (The Magnetic Properties of $Fe_{87}Zr_{7}B_{5}Ag_{1}$(at.%) Amorphous Alloy)

  • 김병걸;송재성;김현식;오영우
    • 한국자기학회지
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    • 제5권1호
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    • pp.8-14
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    • 1995
  • $Fe_{87}Zr_{7}B_{6}$(at.%)조성의 합금에 Fe에 대해 비고용원소인 Ag를 B와 1.0at.% 치환한 $Fe_{87}Zr_{7}B_{5}Ag_{1}$(at.%) 조성의 비정질리본을 액체급냉법으로 제조하여, 연자 기특성을 조사하였다. 급냉응고된 비정질리본의 연자기특성을 향상시키기 위하여 $300~600^{\circ}C$에서 $50^{\circ}C$ 간격으로 열처리한 후, 비정질리본의 연자기특성 및 미세조직의 변화를 조사하였다. 열처리방 법은 진공분위기에서 무자장중 열처리하여 상온까지 노냉했다. $Fe_{87}Zr_{7}B_{5}Ag_{1}$ 비 정질리본을 $400^{\circ}C$에서 1시간 등온열처리하였 때, 보자력$(H_{c})$ 15 mOe, 초투자율$(\mu_{i})$ 288,000(1kHz, 2mOe) 그리고 철손$(W_{c})$ 50 W/kg(100kHz, 1,000G)이라는 Co계 비정질합금에 필적할 수 있는 대단히 우수한 연자성재료가 개발되었다. 이와 같은 우수한 연자기특성은 Fe 와 비고용원소인 Ag 를 소량 첨가함에 따라 열처리에 의해 2~3 nm 크기의 미세한 Fe-rich cluster 형성에 따른 전기저항의 증가, 자왜의 감소 그리고 자구(domain) 크기의 감소에 기인한다고 생각된다.

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인체에 유해하지 않은 원소를 사용한 Ti 계 벌크 비정질 합금 개발 (Development of Ti-based Bulk Metallic Glasses with Non-toxic Elements)

  • 이철규;이승훈
    • 한국주조공학회지
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    • 제32권4호
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    • pp.177-180
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    • 2012
  • Ti-based bulk metallic glasses with high glass forming ability were developed through a systematic alloy design technique. The main alloy design strategy was the selection of alloying elements that may not be toxic in the human body. The $Ti_{45.0}Cu_{40.1}Zr_{12.7}Si_{2.2}$ alloy could be cast into an amorphous rod with the diameter of 3 mm by a suction casting technique using Cu mold. The compressive strength of the amorphous rod was measured as 1826 MPa. Since the Ti-based amorphous alloys consist of non-toxic elements, they can be widely used as bio-materials and eco-materials with unique and beneficial properties.

Thermal stability, magnetic and magnetocaloric properties of Gd55Co35M10 (M = Si, Zr and Nb) melt-spun ribbons

  • Jiao, D.L.;Zhong, X.C.;Zhang, H.;Qiu, W.Q.;Liu, Z.W.;Ramanujan, R.V.
    • Current Applied Physics
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    • 제18권12호
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    • pp.1523-1527
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    • 2018
  • The thermal stability, magnetic and magnetocaloric properties of $Gd_{55}Co_{35}M_{10}$ (M = Si, Zr and Nb) melts-pun ribbons were studied. The relatively high reduced glass transition temperature ($T_{x1}/T_m$ > 0.60) and low melting point ($T_m$) resulted in excellent glass forming ability (GFA). The Curie temperatures ($T_C$) of melt-spun amorphous ribbons $Gd_{55}Co_{35}M_{10}$ for M = Si, Zr and Nb were 166, 148 and 173 K, respectively. For a magnetic field change of 2 T, the values of maximum magnetic entropy change $(-{\Delta}S_M)^{max}$ for $Gd_{55}Co_{35}Si_{10}$, $Gd_{55}Co_{35}Zr_{10}$ and $Gd_{55}Co_{35}Nb_{10}$ were found to be 2.86, 4.28 and $4.05J\;kg^{-1}K^{-1}$, while the refrigeration capacity (RC) values were 154, 274 and $174J\;kg^{-1}$, respectively. The $RC_{FWHM}$ values of amorphous alloys $Gd_{55}Co_{35}M_{10}$ (M = Si, Zr and Nb) are comparable to or larger than that of $LaFe_{11.6}Si_{1.4}$ crystalline alloy. Large values of $(-{\Delta}S_M)^{max}$ and RC along with good thermal stability make $Gd_{55}Co_{35}M_{10}$ (M = Si, Zr and Nb) amorphous alloys be potential materials for magnetic cooling operating in a wide temperature range from 150 to 175 K, e.g., as part of a gas liquefaction process.

Fe-계 비정질 합금의 절연 코팅이 자기적 성질에 미치는 영향 (Influence of Insulated Coatings on The Magnetic Properties of Fe-Based Amorphous Alloy)

  • 김현식;오영우;김병걸;전순종;김기욱;민복기;송재성
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1994년도 하계학술대회 논문집 C
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    • pp.1311-1313
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    • 1994
  • The development of an insulated coating which can be used for amorphous alloys is extremely important from the practical point of view. This importance may be enhanced by the influence of the coating on the magnetic properties. The aim of the study is to show how some coating influence the magnetic properties of $Fe_{87}Zr_7B_5Ag_1(at%)$ amorphous alloy.

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Cu-Zr-Al-Be 비정질합금의 결정화거동 및 속도론 (Crystallization Behavior and Kinetics of Cu-Zr-Al-Be Bulk Metallic Glass)

  • 김유찬;에릭플러리;석현광;차필령;이진규;이재철
    • 대한금속재료학회지
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    • 제46권6호
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    • pp.338-344
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    • 2008
  • The crystallization kinetics of the $Cu_{43}Zr_{43}Al_7Be_7$ bulk metallic glass were studied by differential scanning calorimetry(DSC) in the continuous heating and isothermal annealing modes. Only one major peak could be detected on the DSC traces of $Cu_{43}Zr_{43}Al_7Be_7$ bulk amorphous alloy, and the activation energy for crystallization corresponding to the peak determined by the Kissinger method was resulted of 239 kJ/mol. The isothermal kinetic, analyzed by the Johnson-Mehl-Avrami equation yielded values for the Avrami exponents in the range 1.69 to 2.37, which implied a crystallization governed by a three-dimensioned growth. Primary phases were essentially the cubic structure CuZr together with the $Cu_{10}Zr_7$ phase. At higher temperature, the CuZr disappeared while the $Cu_{10}Zr_7$ became predominant. After long term annealing at 731 K, the phases were $Cu_{10}Zr_7$, $Cu_2ZrAl$ and $Al_3Zr_5$.

Cu-Zr-Ag계 비정질 합금의 불혼화 영역이 구조 및 소성에 미치는 영향 (Miscibility Gap in Cu-Zr-Ag Alloy System and its Effect on the Structure and Plasticity of Metallic Glass)

  • 이진주;박경원;김도향;에릭플러리
    • 대한금속재료학회지
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    • 제49권12호
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    • pp.930-936
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    • 2011
  • In the present study, we show that the addition of Ag, an element having a positive enthalpy of mixing with Cu in the liquid state, enables the simultaneous enhancement of the glass forming ability and the plasticity in Cu-Zr-Ag bulk metallic glasses (BMGs). Rods of 4 mm diameter could be prepared with a fully amorphous structure and values of plastic strain up to 18% were measured under a compression mode for compositions around $Cu_{42.5}Zr_{47.5}Ag_{10}$. The possible role of Ag in the change of the atomic structure and the enhancement of the plastic strain in the ternary Cu-Zr-Ag BMGs is discussed based on analyses from transmission electron microscopy and EXAFS (extended X-ray absorption fine structure).