• 제목/요약/키워드: ARB

검색결과 81건 처리시간 0.031초

ARB법에 의한 Cu-Fe-P합금의 초미세결정립 형성 (Formation of Ultrafine Grains in Cu-Fe-P Alloy by Accumulative Roll-Bonding Process)

  • 이성희;한승전;김형욱;임차용
    • 한국재료학회지
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    • 제19권8호
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    • pp.432-436
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    • 2009
  • A Cu-Fe-P copper alloy was processed by accumulative roll-bonding (ARB) for ultra grain refinement and high strengthening. Two 1mm thick copper sheets, 30 mm wide and 300 mm long, were first degreased and wire-brushed for sound bonding. The sheets were then stacked on top of each other and roll-bonded by about 50% reduction rolling without lubrication at ambient temperature. The bonded sheet was then cut into two pieces of the same dimensions and the same procedure was repeated for the sheets up to eight cycles. Microstructural evolution of the copper alloy with the number of the ARB cycles was investigated by optical microscopy (OM), transmission electron microscopy(TEM), and electron back scatter diffraction(EBSD). The grain size decreased gradually with the number of ARB cycles, and was reduced to 290 nm after eight cycles. The boundaries above 60% of ultrafine grains formed exhibited high angle boundaries above 15 degrees. In addition, the average misorientation angle of ultrafine grains was 30 degrees.

ARB법에 의해 강소성가공된 무산소동의 어닐링 특성 (Annealing Characteristics of Oxygen Free Copper Severely Deformed by Accumulative Roll-Bonding Process)

  • 이성희;조준;이충효;한승전;임차용
    • 한국재료학회지
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    • 제15권9호
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    • pp.555-559
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    • 2005
  • An oxygen free copper severely-deformed by eight cycles (an equivalent strain of $\~6.4$) of accumulative roll-bonding (ARB) was annealed at various temperatures ranging from 100 to $300^{\circ}C$. The annealed copper was characterized by transmission electron microscopy (TEM) and tensile & hardness test. TEM observation revealed that the ultrafine grains developed by the ARB still remained up to $150^{\circ}C$, however above $200^{\circ}C$ they were replaced by equiaxed and coarse grains due to an occurrence of the static recrystallization. Tensile strength and hardness of the copper decreased slightly with the annealing temperature up to $150^{\circ}C$, however they dropped largely above $200^{\circ}C$. Annealing characteristics of the copper were compared with those of a commercially pure aluminum processed by ARB and subsequently annealed.

EBSD측정에 의한 반복겹침접합압연된 무산소동의 두께방향으로의 미세조직 변화 분석 (Microstructural Evolution Analysis in Thickness Direction of An Oxygen Free Copper Processed by Accumulative Roll-Bonding Using EBSD Measurement)

  • 이성희;임차용
    • 한국재료학회지
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    • 제24권11호
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    • pp.585-590
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    • 2014
  • Microstructural evolution in the thickness direction of an oxygen free copper processed by accumulative rollbonding (ARB) is investigated by electron back scatter diffraction (EBSD) measurement. For the ARB, two copper alloy sheets 1 mm thick, 30 mm wide and 300 mm long are first degreased and wire-brushed for sound bonding. The sheets are then stacked and roll-bonded by about 50% reduction rolling without lubrication at an ambient temperature. The bonded sheet is then cut to the two pieces of the same dimensions and the same procedure was repeated on the sheets up to eight cycles. The specimen after 1 cycle showed inhomogeneous microstructure in the thickness direction so that the grains near the surface were finer than those near the center. This inhomogeneity decreased with an increasing number of ARB cycles, and the grain sizes of the specimens after 3 cycles were almost identical. In addition, the aspect ratio of the grains decreased with an increasing number of ARB cycles due to the subdivision of the grains by shear deformation. The fraction of grains with high angle grain boundaries also increased with continuing process of the ARB so that it was higher than that of the low angle grain boundaries in specimens after 3 cycles. A discontinuous dynamic recrystallization occurred partially in specimens after 5 cycles.

중국 중재조정의 적법성에 관한 연구 (A Study on the Legality of Arb-Med in China)

  • 이경화;서경
    • 무역상무연구
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    • 제69권
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    • pp.523-541
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    • 2016
  • According to Chinese Arbitration Law, combination of mediation with arbitration means that in the process of arbitration, arbitrator may conduct mediation proceedings for the case they are handling, provided both parties agree to do so. If mediation succeeds and the parties reach a settlement agreement, the arbitrators may render a consent award or a written mediation statement in accordance with the contents of the settlement agreement. If mediation fails, the arbitration proceedings will be resumed until the case is concluded by making of an arbitral award. There is no formal name of this system in China, it is called "combination of mediation with arbitration", "mediation in arbitration process" or "arbitration-mediation", the author of this thesis select "arbitration-mediation" and make it simply as "Arb-Med". This thesis concentrates on three issues that arbitrators and the parties have to clarify and pay attention to once they choose to use Arb-Med. The first part is about the 'waivable problems', include waive the right to challenge a arbitrator who act as a mediator at the same time with parties' approval, as well as the question about the waiver of the arbitrator's duty to disclose confidential information obtained during mediation. The second part is 'public policy in Arb-Med', introduces the concept of public policy, the bias may arise the complaint about public policy, and the due procedure problem. And the last part is about the award deals with a difference not contemplated by or not falling within the terms of the submission to arbitration, or it contains decisions on matters beyond the scope of the submission to arbitration, especially about the award including some contents which has relation to third party's interests.

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반복겹침접합 압연공정에 의해 제조한 초미세립 AA1050/AA5052 복합알루미늄합금판재의 어닐링 특성 (Annealing Characteristics of Ultrafine Grained AA1050/AA5052 Complex Aluminum Alloy Sheet Fabricated by Accumulative Roll-Bonding)

  • 이성희;이광진
    • 한국재료학회지
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    • 제21권12호
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    • pp.655-659
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    • 2011
  • An ultrafine grained complex aluminum alloy was fabricated by an accumulative roll-bonding (ARB) process using dissimilar aluminum alloys of AA1050 and AA5052 and subsequently annealed. A two-layer stack ARB process was performed up to six cycles without lubricant at an ambient temperature. In the ARB process, the dissimilar aluminum alloys, AA1050 and AA5052, with the same dimensions were stacked on each other after surface treatment, rolled to the thickness reduction of 50%, and then cut in half length by a shearing machine. The same procedure was repeated up to six cycles. A sound complex aluminum alloy sheet was fabricated by the ARB process, and then subsequently annealed for 0.5h at various temperatures ranging from 100 to $350^{\circ}C$. The tensile strength decreased largely with an increasing annealing temperature, especially at temperatures of 150 to $250^{\circ}C$. However, above $250^{\circ}C$ it hardly decreased even when the annealing temperature was increased. On the other hand, the total elongation increased greatly above $250^{\circ}C$. The hardness exhibited inhomogeneous distribution in the thickness direction of the specimens annealed at relatively low temperatures, however it had a homogeneous distribution in specimens annealed at high temperatures.

누적압연접합에 의한 5052 Al 합금의 결정립 미세화와 기계적 특성 연구 (An Investigation of Microstructural Evolution and Sliding Wear Behavior of Ultra-Fine Grained 5052 Aluminum Alloy Fabricated by a Accumulative Roll-Bonding Process)

  • 하종수;강석하;김용석
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2003년도 춘계학술대회논문집
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    • pp.84-87
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    • 2003
  • Microstructural evolution and dry sliding wear behavior of ultra-fine grained 5052 Al alloy obtained by an accumulative roll-bonding process have been investigated. After 7 ARB cycles, ultra-fine grains with large misorientations between neighboring grains were obtained. The grain size was about 0.2$\mu\textrm{m}$. The hardness, tensile and yield strengths of the ultra-fine grained alloy increased as the amount of accumulated strain increased with the ARB cycles. Sliding wear teats of the ultra-fine grained 5052 Al alloy were conducted at room temperature. Wear rate of the ultra-fine grained alloy increased in spite of the increase of hardness. Surfaces of the worn specimens were examined with SEM to investigate wear mechanism of the ultra-fine grained alloy.

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누적압연접합에 의한 5052 Al 합금의 결정립 미세화와 기계적 특성 연구 (An Investigation of Microstructural Evolution and Sliding Wear Behavior of Ultra-Fine Grained 5052 Aluminum Alloy Fabricated by an Accumulative Roll-Bonding Process)

  • 하종수;강석하;김용석
    • 소성∙가공
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    • 제12권4호
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    • pp.376-381
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    • 2003
  • Microstructural evolution and dry sliding wear behavior of ultra-fine grained 5052 Al alloy obtained by an accumulative roll-bonding process have been investigated. After 7 ARB cycles, ultra-fine grains with a large misorientation between neighboring grains were obtained. The grain size was about 0.2 $\mu$m. The hardness, tensile and yield strengths of the ultra-fine grained alloy increased as the amount of accumulated strain increased with the ARB cycles. Sliding wear tests of the ultra-fine grained 5052 Al alloy were conducted at room temperature. Wear rate of the ultra-fine grained alloy increased in spite of the increase of hardness. Surface of the worn specimens were examined with SEM to investigate wear mechanism of the ultra-fine grained alloy.

중국 중재제도의 특징과 그 역사.문화적 배경에 관한 연구 (A Study on the Characteristics of Chinese Arbitration System and Its Historical and Cultural Background)

  • 오원석;이경화
    • 한국중재학회지:중재연구
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    • 제24권2호
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    • pp.161-181
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    • 2014
  • This thesis, which mainly focuses on the characteristics of the Chinese arbitration system, will mainly deal with three characteristics and analyze the causes that directly or indirectly influence them. The first characteristic is China does not recognize ad hoc arbitration. Ad hoc arbitration is the initial form of arbitration, and it occupies an important position in many countries; however, China's judicial system does not recognize it. There are many disadvantages for building a system of ad hoc arbitration in China; i. e., the arbitration system in China is undeveloped and shot-time established, and it lacks social and civil society basis, along with a credit system, which the Western ad hoc arbitration relies on. The second characteristic is the existence of excessive judicial supervision and control over arbitration in China. Judicial supervision over arbitration has been the customary practice in each country of the modern world, but sharp variation exists in the legal stipulations and the courts' attitude toward the standard to be applied in the supervision over arbitration. In China, there has always been a controversy over judicial supervision, and the standards applied in the supervision over arbitration by courts in different regions are less than identical. The last characteristic is the existence of a combination of mediation with arbitration, which is called Arb-Med in China. Such means that in the process of arbitration, the arbitrator may conduct mediation proceedings for the case it is handling if both parties agree to do so. Under the Chinese law, Arb-Med may lead to a binding and enforceable outcome. However, it has several legal disadvantages and almost no country adopts this system. China still insists that this system will go on because Arb-Med was first made in China, and its effect was proven through long-time practice in CIETAC.

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Anthraquinone계 염료의 제거를 위한 호알칼리성 Bacillus sp.의 분리와 성장 특성 (Isolation and Growth Characteristics of Alkalophilic Bacillus sp. for Removal of Anthraquinone Dye.)

  • 김정목
    • 한국미생물·생명공학회지
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    • 제29권2호
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    • pp.67-71
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    • 2001
  • 자연계로부터 anthraquinone계 염료인 Remazol brilliant blue R를 분해.탈색하는 호알칼리성 균주를 분리하여 Bacillus sp. ARB1으로 명명하고 성장특성을 조사하였다. 최적 배양온도와 pH는 $35^{\circ}C$, pH 9.0로 나타났다. 배양액의 초기 pH가 10과 10.5일 경우 배양시간의 경과에 따라 pH 값이 점점 감소하여 40시간 후 9.3, 9.4로 각각 감소하였다. 진탕배양의 경우가 정치배양의 경우보다 Bacillus sp. ARB1의 탈색율이 현저히 높았다. 최적 배양조건에서 Bacillus sp. ARB1을 회분배양한 결과 배양 32시간 후 93%의 탈색율을 나타내었다. 실제 염색가공폐수를 사용한 회분배양에서 40시간 후에 탈색율은 78%로 나타났다.

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ARB법에 의한 인탈산동의 결정립초미세화 및 고강도화 (Ultra Grain Refinement and High Strengthening of Deoxidized Low-Phosphorous Copper by Accumulative Roll-Bonding Process)

  • 이성희;한승전;임차용
    • 한국재료학회지
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    • 제16권9호
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    • pp.592-597
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    • 2006
  • A deoxidized low-phosphorous (DLP) copper was processed by accumulative roll-bonding (ARB) for ultra grain refinement and high strengthening. Two copper sheets 1 mm thick, 30 mm wide and 300 mm long are first degreased and wire-brushed for sound bonding. The sheets are then stacked to each other, and roll-bonded by about 50% reduction rolling without lubrication at ambient temperature. The bonded sheet is then cut to the two pieces of same dimensions and the same procedure was repeated to the sheets up to eight cycles (${\varepsilon}{\sim}6.3$). TEM observation revealed that ultrafine grains were developed after the 4th cycle, and their size decreased at higher cycles. Tensile strength of the copper increased with the equivalent strain, and it reached 547 MPa which was 3 times higher than that of the initial material. It is concluded that the ARB process is an effective method for high strengthening of the DLP copper.