• 제목/요약/키워드: Cu stress

검색결과 534건 처리시간 0.021초

비정질 $Ti_{50}-Ni_{30}-Cu_{20}$ 리본의 결정화 열처리와 형상기억특성 변화 (Shape Memory Characteristics and Crystallization Annealing of Amorphous $Ti_{50}-Ni_{30}-Cu_{20}$ Ribbons)

  • 김연욱;윤영목
    • 한국주조공학회지
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    • 제28권1호
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    • pp.31-36
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    • 2008
  • Ti-Ni-Cu alloys are very attractive shape memory alloys for applications as actuators because of a large transformation elongation and a small transformation hysteresis. Rapidly solidified Ti-Ni alloy ribbons have been known to have the shape memory effect and superelasticity superior to the alloy ingots fabricated by conventional casting. In this study, solidification structures and shape memory characteristics of $Ti-Ni_{30}-Cu_{20}$ alloy ribbons prepared by melt spinning were investigated by means of DSC and XRD. Operating parameters to fabricate the amorphous ribbons were the wheel velocity of 55 m/s and the melt spinning temperature of $1500^{\circ}C$. The crystallization temperature was measured to be $440^{\circ}C$. The crystallized ribbons exhibited very fine microstructure after annealing at $440^{\circ}C$ for 10 minutes and $460^{\circ}C$ for 5 minutes and was deformed up to about 6.8% and 6.23% in ductile manner, respectively. Stress-strain curve of the ribbon exhibited a flat stress-plateau at 64 MPa and this is associated with the stress-induced a B2-B19 martensitic transformation. During cycle deformation with the applied stress of 220 MPa, transformation hysteresis and elongation associated with the B2-B19 transformation were observed to be $4.3^{\circ}C$ and 3.6%.

중간가공열처리한 AI-Li계 합금의 고온변형거동 (The Hot Deformation Behaviors of Intermediate Thermo-Mechanical Treated Al-Li Based Alloy)

  • 유창영;진영철
    • 열처리공학회지
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    • 제4권3호
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    • pp.1-6
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    • 1991
  • In this study, intermediate thermo-mechanical treated Al-2.0 wt%Li, and Al-2.0 wt%Li-1.2 wt%Cu-1.0 wt%Mg-0.12 wt%Zr alloys were tested in tension at $10^{\circ}C$ and elevated temperature(100, 200 and $300^{\circ}C$). The results are follows : The tensile strength of Al-Li-Cu-Mg-Zr alloy is the highest but the elongation of Al-Li alloy is the highest(106%) among the all alloys in tension at $300^{\circ}C$. The Portervin-LeChartlier effect is showed in AI-Li-Cu-Mg-Zr alloy at 10 and $100^{\circ}C$, because of tangled dislocation by Mg and Cu. In the true stress-strain curves of all alloy, the peaks of stress at $300^{\circ}C$ are showed at the strain less than 0.1. In the binary alloy, the dynamic restoration process at 200 and $300^{\circ}C$ is nearly similar to dynamic recovery type. The hot deformation stress is decreased with increase of dynamic recovery degree, but the elongation is increased. When the strain the strain rate are constant, the temperature dependence of hot deformation stress is increased with increase of deformation temperature. The elongation and degree of dynamic recovery are decreased with increase of hot deformation activation energy, but the deformation stresses slightly increased.

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Measurement reliability of irreversible stress/strain limits in Sn-Cu double layer stabilized IBAD/RCE-DR processed GdBCO coated conductor tapes under uniaxial tension at 77 K

  • Bautista, Zhierwinjay;Diaz, Mark Angelo;Shin, Hyung-Seop;Lee, Jae-Hun
    • 한국초전도ㆍ저온공학회논문지
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    • 제20권4호
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    • pp.36-40
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    • 2018
  • In this study, the electromechanical properties in Sn-Cu double layer stabilized GdBCO coated conductor (CC) tapes with and without external lamination under uniaxial tension were examined at 77 K and self-field. Their irreversible stress and strain limits were determined using a loading-unloading scheme based on different critical current ($I_c$) recovery criteria. The repeated tests were performed and statistical estimation was done to check the reproducibility depending on the criterion adopted in evaluating the electromechanical properties. From the results, it showed that the Sn-Cu double-layer stabilized CC tapes have the higher irreversible stress limit, but lower irreversible strain limit as compared to brass laminated ones. Through the repeated tests, it can be found that a small scattering of irreversible limits existed in both CC tape samples. Finally, similar strain sensitivity of $I_c$ in both CC tapes was obtained.

피로인산구리용액으로부터 전기도금 된 Cu 필름의 특성에 미치는 도금조건의 영향 (Effect of Deposition Conditions on Properties of Cu Thin Films Electrodeposited from Pyrophosphate Baths)

  • 신동율;심철용;구본급;박덕용
    • 전기화학회지
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    • 제16권1호
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    • pp.19-29
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    • 2013
  • 피로인산구리용액에서 전기도금공정을 이용하여 상온과 $55^{\circ}C$에서 각각 제조된 Cu박막의 특성에 미치는 전류밀도, 도금용액 온도, pH의 영향에 대한 연구를 수행하였다. 전류효율은 전류밀도가 증가함에 따라 감소하였으나, 도금용액의 온도가 증가함에 따라 증가하는 경향을 나타내었다. 그러나 pH 는 전류효율에 거의 영향을 미치지는 않았으며, 상온과 $55^{\circ}C$에서 모두 90% 이상으로 측정되었다. 상온에서 전기도금 된 Cu 박막의 잔류응력은 전류밀도의 증가에 따라 감소하며, 60 $mA/cm^2$ 이상에서는 거의 0에 근접하였다. $55^{\circ}C$에서 전기도금 된 Cu 박막은 0~40 MPa의 잔류응력을 나타내었다. 상온에서 도금하는 경우 수지상 표면 형상이 30 $mA/cm^2$ 이상의 전류밀도로부터 관찰되었고, $55^{\circ}C$에서는 100 $mA/cm^2$ 이상의 전류밀도부터 관찰되었다. 상온과 $55^{\circ}C$의 도금용액으로부터 전기도금 된 Cu 박막은 거의 (111) 피크들로 구성되어 있다. 특히 $55^{\circ}C$, 30 $mA/cm^2$에서 전기도금 된 Cu 박막의 경우 (111) 피크의 강한 우선방향을 나타내었다.

전기도금 된 Cu 필름 특성에 미치는 피로인산구리용액의 화학성분의 영향 (Influence of Chemical Composition of Pyrophosphate Copper Baths on Properties of Electrodeposited Cu Films)

  • 신동율;구본급;박덕용
    • 전기화학회지
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    • 제18권1호
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    • pp.7-16
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    • 2015
  • 전기도금공정을 이용하여 상온에서 제조된 Cu박막의 특성에 미치는 피로인산구리용액의 화학성분($Cu^{2+}$ 농도, $K_4P_2O_7$ 농도, 첨가제 농도)의 영향에 대한 연구를 수행하였다. 전류효율은 도금용액의 $Cu^{2+}$ 농도가 0.3 M까지 높아짐에 따라 거의 100%까지 증가하는 경향을 나타내었다. $K_4P_2O_7$ 농도는 1.5~1.8 M 농도에서 전류효율의 감소를 나타내었으나, 0.9~1.3 M과 2.1~2.4 M에서는 거의 100%의 전류효율을 나타내었다. 첨가제의 농도 변화는 전류효율에는 거의 영향을 미치지 않았다. 전기도금 된 Cu 박막의 잔류응력은 도금용액의 $Cu^{2+}$ 농도가 0.15 M 이하에서는 약 20 MPa로 측정되었으나, $Cu^{2+}$ 농도가 증가함에 따라 증가하다가 0.25 M 에서 약 120 MPa의 최대치를 나타내었다. 한편 도금용액의 $K_4P_2O_7$ 농도가 0.9 M로부터 2.4M로 증가할수록 잔류 응력은 80MPa로부터 0 MPa까지 감소하는 경향을 나타내었으며, 첨가제의 농도는 잔류응력에 영향을 미치지 않은 것으로 관찰되었다. 표면형상의 경우 $Cu^{2+}$ 농도와 $K_4P_2O_7$ 농도는 상당한 영향을 미쳤으나, 첨가제는 약간의 영향만을 나타내었다. XRD 분석 결과 $Cu^{2+}$ 농도와 $K_4P_2O_7$ 농도는 Cu 박막의 미세조직에 상당한 영향을 미쳤으나, 첨가제는 거의 영향을 미치지 않는 것으로 나타났다. $Cu^{2+}$ 농도와 $K_4P_2O_7$ 농도가 증가할수록 (111) 피크의 강한 우선방향성이 나타내었다.

Stress and Stress Voiding in Cu/Low-k Interconnects

  • Paik, Jong-Min;Park, Hyun;Joo, Young-Chang
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제3권3호
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    • pp.114-121
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    • 2003
  • Through comparing stress state of TEOS and SiLK-embedded structures, the effect of low-k materials on stress and stress distribution in via-line structures were investigated using three-dimensional finite element analyses. In the case of TEOS-embedded via-line structures, hydrostatic stress was concentrated at the via and the top of the lines, where the void was suspected to nucleate. On the other hand, in the via-line structures integrated with SiLK, large von-Mises stress is maintained at the via, thus deformation of via is expected as the main failure mode. A good correlation between the calculated results and experimentally observed failure modes according to dielectric materials was obtained.

가공온도에 따라 다이업셋한 Nd-Fe-B-Cu 합금의 응력과 결정에 관한 연구 (A Study on the Stress and Crystal in Die-Upsetted Nd-Fe-B-Cu Alloys as a Function of Working Temperature)

  • 박정덕;양현수;곽창섭;정원용
    • 열처리공학회지
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    • 제7권1호
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    • pp.61-71
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    • 1994
  • This study is to investigate the stress distributions, crystal orientations and magnetic properties during die-upsetting according to working temperature of Nd-Fe-B-Cu alloys. The stress distributions in the specimens during compressing process were calculated by a finite element method program(SPID). The calculated stresses were effective stress (${\sigma}_{eff}$), compression stress(${\sigma}_z$), radial direction stress(${\sigma}_r$) rotational direction stress(${\sigma}_e$) and shear stress(${\tau}_{rz}$). The stress distributions of ${\sigma}_z$, obtained by a computer simulation showed that the stress components causing the magnetic alignment during die-upsetting of the cast magnets were very high at the center-part of a specimen, and decreased toward the periphery-part of a specimen. In view of the above results the magnetic properties should be better at the center-part of a specimen than any other parts. But the measured magnetic properties were better at the mid-part. These results should be due to the fact that the specimens were casted. Normally the magnetic properties are affected by the casting process as well as by the stress levels. ${\sigma}_r$, ${\sigma}_e$ are thought to affect the liquid phase flowing and domain patterns, respectively. The influence of ${\tau}_{rz}$ was trivial, ${\sigma}_{eff}$ distributed similar throughout the specimen. The Nd-rich phase appeared at the peripheral of the specimen where the stress level of ${\sigma}_r$, ${\sigma}_z$, was low or the stress level of ${\sigma}_e$ was high. The Nd-rich phase was squeezed out during die-upsetting. This phase had an effect on the crystal orientation and grain growth. The stress distributions of alloy were irregular at the parts of the specimen where the die contacted with specimen.

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피로인산동 도금용액으로부터 전기도금 된 Cu 도금층의 물성에 미치는 인가전류밀도의 영향 (Influence of Applied Current Density on Properties of Cu thin layer Electrodeposited from Copper Pyrophosphate Bath)

  • 윤필근;박덕용
    • 한국표면공학회지
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    • 제53권4호
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    • pp.190-199
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    • 2020
  • Copper pyrophosphate baths were employed in order to study the dependencies of current efficiency, residual stress, surface morphology and microstructure of electrodeposited Cu thin layers on applied current density. The current efficiency was obtained to be more than about 90 %, independent of the applied current density. Residual stress of Cu electrodeposits was measured to be in the range of -30 MPa and 25 MPa with the increase of applied current density from 0.5 to 15 mA/㎠. Relatively smooth surface morphologies of the electodeposited Cu layers were obtained at an intermediate current range between 3 and 4 mA/㎠. The Cu electrodeposits showed FCC(111), FCC(200), and FCC(220) peaks and any preferred orientation was not observed in this study. The average crystalline size of Cu thin layers was measured to be in the range of 44~69 nm.

HSLA-100강 및 HY-100강의 응력제거처리 균열에 관한 연구 (A Study on the Stress Relief Cracking of HSLA-100 and HY-100 steels)

  • 박태원;심인옥;김영우;강정윤
    • Journal of Welding and Joining
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    • 제14권3호
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    • pp.48-57
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    • 1996
  • A study was made to examine the characteristics of base metal and stress relief cracking(SRC) of heat affected zone(HAZ) for HY-100 and Cu-bearing HSLA-100 steels. The Gleeble thermal/mechanical simulator was used to simulate the SRC/HAZ. The details of mechanical properties of base plate and SRC tested specimens were studied by impact test, optical microscopy and scanning electron microscopy. The specimens were aged at $650^{\circ}C$ for HSLA-100 steel and at $660^{\circ}C$ for HY-100 steel and thermal cycled from $1350^{\circ}C$ to $25^{\circ}C$ with a cooling time of $\Delta$t_${800^{circ}C/500^{circ}C}$=21sec. corresponds to the heat input of 30kJ/cm. The thermal cycled specimens were stressed to a predetermined level of 248~600MPa and then reheated to the stress relief temperatures of $570~620^{\circ}C$. The time to failure$(t_f)$ at a given stress level was used as a measure of SRC susceptibility. The strength, elongation and impact toughness of base plate were greater in HSLA-100 steel than in HY-100 steel. The time to failure was decreased with increasing temperature and/or stress. HSLA-100 steel was more susceptible to stress relief cracking than HY-100 steel under same conditions. It is thought to be resulted from the precipitation of $\varepsilon$-Cu phase by dynamic self diffusion of solute atoms. By the precipitation of $\varepsilon$-Cu phase, the differential strengthening of grain interior relative to grain boundary may be greater in the Cu-bearing HSLA-100 steel than in HY-100 steel. Therefore, greater strain concentration at grain boundary of HSLA-100 steel results in the increased SRC susceptibility. The activation energies for SRC of HSLA-100 steel are 103.9kcal/mal for 387MPa and 87.6kcal/mol for 437MPa and that of HY-100 steel is 129.2kcal/mol for 437MPa.

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TFT-LCDs에 적용 가능한 Cu-Ag 박막에 대한 Mo 기판 위에서의 특성조사 (Characteristic of Cu-Ag Added Thin Film on Molybdenum Substrate for an Advanced Metallization Process)

  • 이현민;이재갑
    • 한국재료학회지
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    • 제16권4호
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    • pp.257-263
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    • 2006
  • We have investigated the effect of silver added to Cu films on the microstructure evolution, resistivity, surface morphology, stress relaxation temperature, and adhesion properties of Cu(Ag) alloy thin films deposited on Mo glue layer upon annealing. In addition, pure Cu films deposited on Mo has been annealed and compared. The results show that the silver in Cu(Ag) thin films control the grain growth through the coarsening of its precipitates upon annealing at $300^{\circ}C{\sim}600^{\circ}C$ and the grain growth of Cu reveals the activation energy of 0.22 eV, approximately one third of activation energy for diffusion of Ag dopant along the grain boundaries in Cu matrix (0.75 eV). This indicates that the grain growth can be controlled by Ag diffusion along the grain boundaries. In addition, the grain growth can be a major contributor to the decreased resistivity of Cu(Ag) alloy thin films at the temperature of $300^{\circ}C{\sim}500^{\circ}C$, and decreases the resistivity of Cu(Ag) thin films to $1.96{\mu}{\Omega}-cm$ after annealing at $600^{\circ}C$. Furthermore, the addition of Ag increases the stress relaxation temperature of Cu(Ag) thin films, and thus leading to the enhanced resistance to the void formation, which starts at $300^{\circ}C$ in the pure Cu thin films. Moreover, Cu(Ag) thin films shows the increased adhesion properties, possibly resulting from the Ag segregating to the interface. Consequently, the Cu(Ag) thin films can be used as a metallization of advanced TFT-LCDs.