• 제목/요약/키워드: Intermediate Annealing

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500 m급 Bi-2223/Ag 고온초전도 선재의 균일 가공 및 임계전류 특성 (Uniform deformation and Critical Current properties of 500 m class Bi-2223/Ag HTS tapes)

  • 이동훈;양주생;최정규;윤진국;황선역;김상철;하홍수;하동우;오상수
    • 한국초전도저온공학회:학술대회논문집
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    • 한국초전도저온공학회 2003년도 학술대회 논문집
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    • pp.85-87
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    • 2003
  • Intermediate annealing was carried out during wire drawing for uniform deformation of 500 m class Bi-2223/Ag HTS tapes. Wire drawing force was measured to evaluate the uniformity of wire deformation along the length. To prevent sausage and filament breakage of wire, drawing stress was controlled below 200 MPa by using intermediate annealing process. Thickness and width of the rolled tapes was measured 0.23 mm and 4.1 mm with low deviation $\pm$ 0.08 mm and $\pm$ 0.09 mm, respectively. The critical current of the 500 m tapes was measured 33.7 A $\pm$ 3.7 A by continuous critical current measurement system.

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분말 압연에 의해 제조된 퍼말로이(PB, PC)의 자성 특성 (Magnetic Properties of Permalloy(PB, PC) Strips Fabricated by Powder Rolling Process)

  • 이동원
    • 한국분말재료학회지
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    • 제3권1호
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    • pp.13-24
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    • 1996
  • Two grades of Permalloy strips, Fe-45Ni(PB) and Fe-78Ni-4Mo-5Cu(PC) were fabricated by powder rolling process from elemental powder mixtures. The roll compacted green strips were sintered, homogenized, cold rolled with or without an intermediate annealing and finally heat treated to measure magnetic properties. For a given thickness reduction, rolling with an intermediate annealing was found more effective to achieve a full densification with no visible micropores and also to obtain better magnetic properties. Increasing the final rolling reduction also produced a marked improvement of the magnetic properties whereas the cooling rate during the final heat treatment has little effect in both grades. Addition of a small amount, 0.4% Mn slightly degraded the properties. As an overall, The PM strips produced via powder rolling yielded the similar soft magnetic properties to the corresponding commercial grades produced via wrought processing.

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고온초전도 PIT 장선재 제조 및 특성 평가 (Fabrication and evaluation of superconducting properties of HIS PIT long tapes)

  • 하홍수;이동훈;양주생;황선역;최정규;김상철;하동우;오상수;권영길
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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    • pp.597-600
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    • 2003
  • Bi-2223/Ag HTS wires have been fabricated by the PIT(powder in tube)process. Intermediate annealing was carried out to increase the homogenization and uniformity of the superconducting filaments embedded in the silver matrix during the deformation process that is important to sustain the engineering critical current density in long superconducting wire. Intermediate annealing act to release the deformation hardening of the superconducting wires during drawing process. Rolling parameters were investigated to roll the superconducting tapes with uniform thickness, width and winding tensions. Critical current of 60 m long superconducting tapes was measured 54.3 A continuously after final sintering heat treatment. The phase analysis of Bi-2223/Ag superconducting tapes are examined by the XRD.

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솔-젤법에 의한 강유전성 PFN 박막의 제조 및 특성평가 (Fabrication and Characterization of Ferroelectric PFN Thin Film by Sol-Gel Processing)

  • 류재율;김병호;임대순
    • 한국세라믹학회지
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    • 제33권6호
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    • pp.665-671
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    • 1996
  • Ferroelectric Pb(Fe1/2Nb1/2)O3 thin films were successfully fabricated on ITO/Glass substrate by sol-gel proces-sing and characterized to determine the dielectric and electric properties. Viscosity of PEN sol measured to investigate rheological properties was 3.25 cP which was proper for coating. The sol also showed Newtonian behavior. RTA(Rapid Thermal Annealing) was used for the annealing of the thin film and 1200~1700$\AA$ thick PEN thin films were fabricated by repeating the intermediate and the final annealing. After the deposition of Pt as top electrode by vacuum evaporation dielectric and electric properties were measured. Dielectric properties of FFN thin film were enhanced by increasing the perovskite phase fraction with increasing the annealing temperature. Measured dielectric constant of 1700$\AA$ PFN thin film annealed at $650^{\circ}C$ was 890 at 1kHz Capacitatnce density and dielectric loss were 47 fF/${\mu}{\textrm}{m}$2 and 0.47 respectively. As a result of measuring Curie temperature PFN thin films had Curie point with a rang of 110~12$0^{\circ}C$ and showed broad dielectric peak at that point. Leakage current of the PFN thin films were increased with increasing the annealing tempera-ture.

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Reduction of Reconstruction Errors in Kinoform CGHs by Modified Simulated Annealing Algorithm

  • Yang, Han-Jin;Cho, Jeong-Sik;Won, Yong-Hyub
    • Journal of the Optical Society of Korea
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    • 제13권1호
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    • pp.92-97
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    • 2009
  • In this paper, a conventional simulated annealing (SA) method for optimization of a kinoform computer generated hologram (CGH) is analyzed and the SA method is modified to reduce a reconstruction error rate (ER) of the CGH. The dependences of the quantization level of the hologram pattern and the size of the data on the ER are analyzed. To overcome saturation of the ER, the conventional SA method is modified as it magnifies a Fourier-transformed pattern in the intermediate step. The proposed method can achieve a small ER less than 1%, which is impossible in the conventional SA method.

다품종용 회분식 공정에서의 중간 저장 탱크 공유를 위한 최적 생산계획 ; 회분식 조업의 자동화 모델 (Optimal Scheduling of Multi-product Batch Process for Common Intermediate Storage Policy; A Model for Batch Process Automation)

  • 정재학;이인범;양대륙;장근수
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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    • pp.303-308
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    • 1992
  • In this study, we propose a shared storage system which is more efficient policy than MIS(Mixed Intermediate Storage) policy for relatively rare storage system and can be called CIS(Common Intermediate Storage) policy. Using this strategy, we develop a new completion time algorithm and apply it to two kinds of optimal or near optimal scheduling method; combinatorial search and simulated annealing method. We also extend this strategy to other storage policy, for example MIS policy, with PLC(Programmable Logic Controller) logic and on/off action of electronic valves. It thus can be accepted as a basic form of FMS(Flexible Manufacturing System) for operating various storage policies. Finally we suggest the interlocking block to compansate for the shortcoming of CIS policy, i.e, complication of operation and safety, resulting in a basic batch process automation mode.

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나노상 $SnO_2$ 가스센서에서 센서검지특성에 미치는 결정구조의 영향 (Effect of Crystal Structures on the Sensing Properties of Nanophase $SnO_2$ Gas Sensor)

  • 안재평;김선호;박종구;허무영
    • 한국분말재료학회지
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    • 제8권2호
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    • pp.98-103
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    • 2001
  • Metallic tin powder with diameter less than 50 nm was synthesized by inert gas condensation method and subsequently oxidized to tin oxide ($SnO_2$) along the two heat-treatment routes. The $SnO_2$ powder of single phase with a tetragonal structure was obtained by the heat-treatment route with intermediate annealing step-wise oxidation, whereas the $SnO_2$ powder with mixture of orthorhombic and tetragonal phases was obtained by the heat-treatment route without intermediate annealing (direct oxidation). $SnO_2$ gas sensors fabricated from the nano-phase $SnO_2$ powders were investigated by structural observations as well as measurement of electrical resistance. The $SnO_2$ gas sensors fabricated from the mixed-phase powder exhibited much lower sensitivity against $H_2$ gas than those fabricated from the powder of tetragonal phase. Reduced sensitivity of gas sensors with the new orthorhombic phase was attributed to detrimental effects of phase boundaries between orthorhombic and tetragonal phases and many twin boundaries on the charge mobility.

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Effects of Cold Rolling Parameters on Sagging Behavior for Three Layer Al-Si/Al-Mn(Zn)/Al-Si Brazing Sheets

  • S.H. Lee;J.S. Yoon;M.S. Kim;D. Jung
    • 소성∙가공
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    • 제8권3호
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    • pp.227-227
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    • 1999
  • The effects of intermediate annealing (IA) and the final cold rolling (CR) condition on the microstructure and sagging resistance during brazing were investigated using three layer clad sheets composed of the Al-7.5 wt.%Si alloy (filler, thickness: 10 ㎛)/Al-1.3 wt.%Mn based alloy (core, 80㎛)/Al-7.5 wt.%Si alloy (filler, 10㎛). Also, the effect of 1.2∼2 wt.% Zn addition into the core on the sagging resistance of the clad sheets was determined. It was revealed that all the clad sheets fabricated by the optimum condition (IA at 690 K and CR to 20∼45%) show excellent sagging resistance with a limited erosion due to the formation of a coarsely recrystallized grain structure in the core during brazing. It was also revealed that the recrystallization behavior of the Al-1.3 wt.%Mn based alloy is hardly affected by the addition of 1.2-2 wt.%Zn during the brazing cycle. Therefore, the sagging resistance of the clad sheets is found to be governed not by the Zn content added in the A1-1.3wt.%Mn based core, but by the intermediate annealing and final cold rolling condition.

니오븀이 첨가된 Zr 합금 스트립의 부식 및 기계적 특성에 대한 중간열처리 영향 (Effects of Intermediate Heat Treatment on the Corrosion and Mechanical Properties of Zr Alloy Strip Incorporating Nb)

  • 이명호;정양일;최병권;박상윤;김현길;박정용;정용환
    • 대한금속재료학회지
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    • 제47권8호
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    • pp.482-487
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    • 2009
  • In order to investigate the effects of intermediate heat treatment between cold rolling passes on the hardness and corrosion properties of a Zr alloy incorporating Nb (Zr-1.49Nb-0.38Sn-0.20Fe-0.11Cr) strip, three different intermediate heat treatment processes ($580^{\circ}C{\times}4hrs$, $600^{\circ}C{\times}2hrs$ and $620^{\circ}{\times}1hrs$) were designed based on a recrystallization map and an accumulated annealing parameter. Test samples from the different processes were investigated by a hardness test, corrosion test, and microstructure analysis and appropriate heat-treatment conditions were thereupon proposed. The sample subjected to an intermediate heat treatment of $580^{\circ}C{\times}4hrs$ was harder than that undergoing $600^{\circ}C{\times}2hrs$ and $620^{\circ}C{\times}1hr$ while the corrosion resistance of the sample that received an intermediate heat treatment of $580^{\circ}C{\times}4hrs$ was superior to that of the other specimens. Considering the trade-off of hardness and corrosion resistance, an intermediate heat treatment process of $600^{\circ}C{\times}2hrs$ is proposed to improve the manufacturing process of the alloy strip.