• Title/Summary/Keyword: Cu wire

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A Study on the Short-Circuit Characteristics of Vinyl Cords Damaged by External Flame (외부화염에 의해 소손된 비닐 코드의 단락 특성에 관한 연구)

  • Choi Chung-Seog;Kim Hyang-Kon;Shong Kil-Mok
    • Fire Science and Engineering
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    • v.18 no.4
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    • pp.72-77
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    • 2004
  • In this paper, we studied on the short-circuit process, surface structure, and component variation of vinyl cords. In the results of high speed imaging system (HSIS) analysis, as soon as wire covering was damaged by heat, the conductor of wire came in contact with the other conduct of wire, and the short-circuit occurred. Stereomicroscope and SEM analysis indicated that the source part of wire showed V-type form. The molten beads of load part were bigger than those of source part. In the results of EDX analysis, Cu and O were detected in the source part, whereas covering material (Cl, Ca), Cu and O were detected in the load part. The results will help us to find out the cause of electrical fire.

Effect of Mo and Cu Contents on Work Hardening of Cold Drawn Stainless Steel 304H Wires for Spring (스프링용 스테인레스강 304H 신선재의 가공경화에 미치는 Mo와 Cu 농도의 영향)

  • Kim S. W.
    • Korean Journal of Materials Research
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    • v.15 no.10
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    • pp.632-638
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    • 2005
  • To investigate the effect of Mo and Cu contents on tensile strength of cold drawn stainless steel 304H wires, metallographical and mechanical tests were performed for the wire specimens drawn to different drawing strains at room temperature. It was confirmed that the contents of Mo ana Cu have little influence on the tensile strength of drawn specimens, even though the strain induced martensite transformation decreased with increasing the contents of Mo and Cu. These results were explained by the strengthening of the formed martensite itself due to the solid solution effect of interstitial solutes, carbon and nitrogen. The contents of these elements were slightly higher in the specimens containing additionally added Mo and Cu.

Ag-Cu Powders Prepared by Electrical Wire Explosion of Cu-plated Ag Wires (동도금한 은선재의 전기선폭발에 의해 제조한 Ag-Cu분말)

  • Kim, Won-Baek;Park, Je-Shin;Suh, Chang-Youl
    • Journal of Powder Materials
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    • v.14 no.5
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    • pp.320-326
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    • 2007
  • Ag-Cu alloy nano powders were fabricated by the electrical explosion of Cu-plated Ag wires. Ag wires of 0.2mm diameter was electroplated to final diameter of 0.220 mm and 0.307 mm which correspond to Ag-27Cu and Ag-68Cu alloy. The explosion product consisted of equilibrium phases of ${\alpha}-Ag$ and ${\beta}$-Cu. The particle size of Ag-Cu nano powders were 44 nm and 70 nm for 0.220 mm and 0.307 mm wires, respectively. The Ag-Cu nano powders contained less Cu than average value due to higher sublimation energy compared to that of Ag. As a result, micron-sized spherical particles formed from liquid droplets contained higher Cu content.

Commercial MgB2 superconducting wires at Sam Dong

  • Lee, Dong Gun;Choi, Jun Hyuk;Kim, Du Na;Jeon, Ju Heum;Maeda, Minoru;Choi, Seyong;Kim, Jung Ho
    • Progress in Superconductivity and Cryogenics
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    • v.22 no.2
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    • pp.26-31
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    • 2020
  • Since 2014, Sam Dong Co., Ltd. has successfully developed high-performance MgB2 superconducting wires with a kilometer-scale. Herein, we studied performances of various MgB2 wires fabricated by the Sam Dong with different Cu fractions and diameters for practical applications. Critical current densities of our commercial wire, 18+'1'Cu multifilamentary MgB2 wire, are estimated to be 270,000 A/㎠ at 3 T and 4.2 K and 100,000 A/㎠ at 2 T and 20 K, respectively. We further discuss research progress of various MgB2 superconducting wires at Sam Dong Co., Ltd and make an effort to align with customers' requirements.

Variation of Carbonization Pattern and Crystal Structure of Polyvinyl Chloride Wire Under the Thermal Stresses (열 스트레스에 의한 비닐절연전선의 탄화 패턴 및 결정 구조의 변화)

  • Choi, Chung-Seog;Kim, Hyang-Kon
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.57 no.3
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    • pp.332-337
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    • 2008
  • We analyzed carbonization pattern and crystal structure of polyvinyl chloride wire by thermal stress. Copper that is oxidized at normal temperature is a reddish brown. If under the thermal stress range of 500 to 700 [$^{\circ}C$], carbonization and exfoliation occurrence. Section structure of electric wire is same as arrangement of particle in metallograph analysis. But, as thermal stress increases, size of particle is enlarged. Electric wire displays elongation structure in SEM image analysis and elongation structure collapses when receive thermal stress at 300 [$^{\circ}C$]. In EDX analysis, we get the spectra of CuL, CuK, OK, and ClK. FT-IR analysis was shown new spectra with in range of $1,440{\sim}1,430\;[cm^{-1}]$, 1,340 [$cm^{-1}$], 1,240 [$cm^{-1}$].

Microstructure and Synthesis of Ag Spot-coated Cu Nanopowders by Hydrothermal-attachment Method using Ag Colloid (수열흡착법을 이용한 은 점코팅된 구리 나노분말의 합성과 미세조직)

  • Kim, Hyeong-Chul;Han, Jae-Kil
    • Journal of Powder Materials
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    • v.18 no.6
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    • pp.546-551
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    • 2011
  • Ag spot-coated Cu nanopowders were synthesized by a hydrothermal-attachment method (HA) using oleic acid capped Ag hydrosol. Cu nano powders were synthesized by pulsed wire exploding method using 0.4 mm in diameter of Cu wire (purity 99.9%). Synthesized Cu nano powders are seen with comparatively spherical shape having range in 50 nm to 150 nm in diameter. The oleic acid capped Ag hydrosol was synthesized by the precipitation-redispersion method. Oleic acid capped Ag nano particles showed the narrow size distribution and their particle size were less than 20 nm in diameter. In the case of nano Ag-spot coated Cu powders, nanosized Ag particles were adhered in the copper surface by HAA method. The components of C, O and Ag were distributed on the surface of copper powder.

Nanostructures and Mechanical Properties of Copper Nano Powder Compacted by Magnetic Pulsed Compaction (MPC) Method (Magnetic Pulsed Compaction(MPC)법으로 성형된 Cu 나노 분말 성형체의 미세구조 및 기계적 특성)

  • 이근희;김민정;김경호;이창규;김흥회
    • Journal of Powder Materials
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    • v.9 no.2
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    • pp.124-132
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    • 2002
  • Nano Cu powders, synthesized by Pulsed Wire Evaporation (PWE) method, have been compacted by Magnetic Pulsed Cojpaction(MPC) method. The microstructure and mechanical properties were analyzed. The optimal condition for proper mechanical properties with nanostructure was found. Both pure nano Cu powders and passivated nano Cu powders were compacted, and the effect of passivated layer on the mechanical properties was investigated. The compacts by MPC, which had ultra-fine and uniform nanostructure, showed higher density of 95% of theoretical density than that of static compaction. The pur and passivated Cu compacted at $300^{\circ}C$ exhibited maximum hardnesses of 248 and 260 Hv, respectively. The wear resistance of those compacts corresponded to the hardness.

Mechanical and Electrical Properties of an Al-Fe-Mg-Cu-B System Alloy for Electrical Wire Fabricated by Wire Drawing (인발가공에 의해 제조된 전선용 Al-Fe-Mg-Cu-B계 합금의 기계적 및 전기적 특성)

  • Jung, Chang-Gi;Hiroshi, Utsunomiya;Son, Hyeon-Taek;Lee, Seong-Hee
    • Korean Journal of Materials Research
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    • v.27 no.11
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    • pp.597-602
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    • 2017
  • In this study, an Al-0.7wt%Fe-0.2wt%Mg-0.2wt%Cu-0.02wt%B alloy was designed to fabricate an aluminum alloy for electrical wire having both high strength and high conductivity. The designed Al alloy was processed by casting, extrusion and drawing processes. Especially, the drawing process was done by severe deformation of a rod with an initial diameter of 12 mm into a wire of 2 mm diameter; process was equivalent to an effective strain of 3.58, and the total reduction in area was 97 %. The drawn Al alloy wire was then annealed at various temperatures of 200 to $400^{\circ}C$ for 30 minutes. The mechanical properties, microstructural changes and electrical properties of the annealed specimens were investigated. As the annealing temperature increased, the tensile strength decreased and the elongation increased. Recovery or/and recrystallization occurred as annealing temperature increased, and complete recrystallization occurred at annealing temperatures over $300^{\circ}C$. Electric conductivity increased with increasing temperature up to $250^{\circ}C$, but no significant change was observed above $300^{\circ}C$. It is concluded that, from the viewpoint of the mechanical and electrical properties, the specimen annealed at $350^{\circ}C$ is the most suitable for the wire drawn Al alloy electrical wire.

Composite and Spark Plasma Sintering of the Atomized Fe Amorphous Powders and Wire-exploded Cu Nanopowder in Liquid (가스분무 Fe계 비정질 분말과 유체 내 전기선 폭발에 의한 나노 Cu 분말의 복합화와 방전플라즈마 소결)

  • Kim, Jin-Chun;Goo, Wang-Heo;Yoo, Joo-Sik
    • Journal of Powder Materials
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    • v.15 no.4
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    • pp.285-291
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    • 2008
  • Fe based ($Fe_{68.2}C_{5.9}Si_{3.5}B_{6.7}P_{9.6}Cr_{2.1}Mo_{2.0}Al_{2.0}$) amorphous powder were produced by a gas atomization process, and then ductile Cu powder fabricated by the electric explosion of wire(EEW) were mixed in the liquid (methanol) consecutively. The Fe-based amorphous - nanometallic Cu composite powders were compacted by a spark plasma sintering (SPS) processes. The nano-sized Cu powders of ${\sim}\;nm$200 produced by EEW in the methanol were mixed and well coated with the atomized Fe amorphous powders through the simple drying process on the hot plate. The relative density of the compacts obtained by the SPS showed over 98% and its hardness was also found to reach over 1100 Hv.

In-situ Particle Characterization of Cu Nanopowder using Scanning Mobility Particle Sizer in Pulsed Wire Evaporation Method (전기폭발법에서 SMPS를 이용한 Cu 나노분말의 실시간 입자특성평가)

  • 이창우;맹덕영;박중학;유지훈;이재훈;이창규;김흥회
    • Journal of Powder Materials
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    • v.10 no.4
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    • pp.275-280
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    • 2003
  • Synthesis and characteristics of Cu nanopowder were considered by in-situ characterization method using SMPS in pulsed wire evaporation process. With increasing pressure in chamber, particle size and degree of agglomeration increased by increase of collision frequency. Also, it was found from the XRD analyses and BET measurements that crystallite size and particle size decreased with elevating applied voltage. However, SMPS measurements and TEM observation revealed the increase of particle size and degree of agglomeration with increase of applied voltage. These results suggested that particle growth and agglomeration depend on overheating factor in chamber at the early stage and thermal coagulation in filtering system during powder formation until collection.