• Title/Summary/Keyword: Aluminum 5052

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

  • 하종수;강석하;김용석
    • Transactions of Materials Processing
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    • v.12 no.4
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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.

Finite Element Analysis and Experimental Investigation of Non-isothermal Forming Processes for Aluminum-Alloy Sheet Metals. (Part 1. Experiment) (알루미늄 합금박판 비등온 성형공정의 유한요소해석 및 실험적 연구(제1부. 실험))

  • 류호연;배원택;김종호;김성민;구본영;금영탁
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1998.03a
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    • pp.45-52
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    • 1998
  • This study is to investigate the effects of warm deep drawing with aluminum sheets of A1050-H16 and A5052-H32 for improving deep drawability. Experiments for procucing circular cups and square cups were carried out for various working conditions, such as forming temperature and blank shape. The limit drawing ratio(LDR) of 2.63 in warm deep drawing of circular cups in case of A5052-H32 sheet, whereas LDR of A1050-H16 is 2.25, could be obtained and the former was 8 times higher than the value at room temperature. The maximum relative drawing depth for square cups of A5052-H32 material was also about 2 times deeper than the depth drawn at room temperature. The effects of blank shape, and temperature on drawability of aluminum materials as well as thickness distribution of drawn cups were examined and discussed.

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A Study on the fracture behavior of surface hardening treated aluminum alloy under the high velocity impact (고속충격을 받는 표면처리된 알루미늄 합금의 거동에 관한 연구)

  • 손세원;김희재;황도연;홍성희
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.784-789
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    • 2001
  • In order to investigate the fracture behaviors(penetration modes) and the resistance to penetration during ballistic impact of cold-rolled Al 5052 H34 alloy laminates, anodized Al 5052 H34 alloy laminates, and Al 5052 H34 alloy after cold-rolling, ballistic testing was conducted. In general, superior armor material is brittle materials which have a high hardness. Ballistic resistance of these materials was measured by protection ballistic limit(V50), a statical velocity with 50% probability for incomplete penetration. Fracture behaviors and ballistic tolerance, described by penetration modes, are observed respectfully, resulting from V50 test and Projectile Through Plate(PTP) test at velocities greater than V50. PTP tests were conducted with 0$^{\circ}$obliquity at room temperature using 5.56mm ball projectile. V50 tests with 0$^{\circ}$obliquity at room temperature were also conducted with projectiles that were able to achieve near or complete penetration during PTP tests. Surface Hardness, resistance to penetration, and penetration modes of Al 5052 H34 alloy laminates compared to those of cold-rolled Al 5052 H34 alloy laminates and anodized Al 5052 H34 alloy laminates anodized Al 5052 H34 alloy after cold-rolling.

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Determination of Elastic Modulus of Equal-Channel-Angular-Pressed Aluminum 5052 Alloy by Acoustic Material Signature (음향재료신호를 이용한 강소성변형된 알루미늄 5052 합금의 탄성계수 측정)

  • Kim, Chung-Seok;Park, Ik-Keun;Jhang, Kyoung-Young;Miyasaka, Chiaki
    • Journal of the Korean Society for Nondestructive Testing
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    • v.30 no.2
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    • pp.146-154
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    • 2010
  • The effects of severe plastic deformation, equal channel angular pressing, and annealing of Al 5052 alloy on elastic modulus have been studied. The AI 5052 alloy was plastically deformed by ECAP method after solution treatment, and then finally annealing heat treated. Elastic modulus was measured by conventional tensile and nano-indentation test, and also measured on the surface of the specimen using acoustic material signature of the acoustic microscope. The variation in the elastic modulus influenced by plastic deformation and heat treatment, inaccessible by the conventional techniques, was successfully measured by acoustic material signature and obtained the elastic modulus depending on crystal orientation at each grain.

Forming of Metallic Bipolar Plates by Dynamic Loading (Dynamic Load를 이용한 박막 금속 분리판 성형기술)

  • Koo, J.Y.;Kang, C.G.
    • Transactions of Materials Processing
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    • v.21 no.1
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    • pp.5-12
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    • 2012
  • The weight of the bipolar plate is one of the crucial aspects of improving power density in PEMFC stacks. Aluminum alloys have good mechanical properties such as density, electrical resistivity, and thermal conductivity. Furthermore, using aluminum in a bipolar plate instead of graphite reduces the bipolar plate cost and makes machining easier. Therefore in this study, an aluminum alloy was selected as the appropriate material for a bipolar plate. Results from feasibility experiments with the aim of developing fuel cells consisting of Al bipolar plates with multiple channels are presented. Dynamic loading was applied and the formability of micro channels was estimated as a function of punch pressure and die radius. Sheets of Al5052 with a thickness of 0.3mm were used. For a die radius of 0.1mm the formability was optimized with a sine wave dynamic load of 90kN at maximum pressure and 5 cycles of a sine wave punch travel. The experimental results demonstrate the feasibility of the proposed manufacturing technique for producing bipolar plates.

Microstructure and Mechanical Properties of AA6061/AA5052/AA6061 Complex Sheet Fabricated by Cold-Roll Bonding Process (냉간압연접합법에 의해 제조된 AA6061/AA5052/AA6061 복합판재의 미세조직 및 기계적 성질)

  • Hwang, Ju-Yeon;Lee, Seong-Hee
    • Korean Journal of Materials Research
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    • v.29 no.6
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    • pp.392-397
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    • 2019
  • A cold roll-bonding process is applied to fabricate an AA6061/AA5052/AA6061 three-layer clad sheet. Two AA6061 and one AA5052 sheets of 2 mm thickness, 40 mm width, and 300 mm length are stacked, with the AA5052 sheet located in the center. After surface treatment such as degreasing and wire brushing, sample is reduced to a thickness of 1.5 mm by multi-pass cold rolling. The rolling is performed at ambient temperature without lubricant using a 2-high mill with a roll diameter of 400 mm at rolling speed of 6.0 m/sec. The roll bonded AA6061/AA5052/AA6061 complex sheet is then hardened by natural aging(T4) and artificial aging(T6) treatments. The microstructures of the as-roll bonded and age-hardened Al complex sheets are revealed by optical microscopy; the mechanical properties are investigated by tensile testing and hardness testing. After rolling, the roll-bonded AA6061/AA5052/AA6061 sheets show a typical deformation structure in which grains are elongated in the rolling direction. However, after T4 and T6 aging treatment, there is a recrystallization structure consisting of coarse equiaxed grains in both AA5052 and AA6061 sheets. The as roll-bonded specimen shows a sandwich structure in which an AA5052 sheet is inserted into two AA6061 sheets with higher hardness. However, after T4 and T6 aging treatment, there is a different sandwich structure in which the hardness of the upper and lower layers of the AA6061 sheets is higher than that of the center of the AA5052 sheet. The strength values of the T4 and T6 age-treated specimens are found to increase by 1.3 and 1.4 times, respectively, compared to that value of the starting material.

A Study on the ballistic performance and fracture mode of anodized Aluminum 5052-H34 alloy laminates (알루미늄 5052-H34 합금 적층재의 방탄성능과 파괴모드에 관한 연구)

  • 손세원;김희재;박영의;홍성희
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.11a
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    • pp.507-512
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    • 2000
  • The ob.jective of this study is to determine fracture behaviors(penetrati0n modes) and resistance to penetration duringballistic impact of Al 5052-H34 alloy laminates and anodized Al 5052-H34 alloy laminates. Resistance to penetration is determined by $V_{50}$ ballistic limit, a statical velocity with 50% probability for complete penetration, test method. Fracture behaviors and ballistic tolerance, described by penetration modes, are respectfully observed that result from V50 test and Projectile Through Plates (PTP) test at velocities greater than $V_{50}$. PTP tests were conducted with 0" obliquity at room temperature using 5.56mm ball projectile. $V_{50}$ tests with 0" obliquity at room temperature were conducted with projectiles that were able to achieve near or complete penetration during PTP tests. Surface Hardness, resistance to penetration, and penetration modes of A1 5052-H34 alloy laminates compared to those of anodized Al 5052-H34 alloy laminates.y laminates.

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An Investigation of Mechanical Properties and Sliding Wear Behavior of Ultra-Fine Grained 5052 Aluminum Alloy Fabricated by a Accumulative Roll-Bonding Process (누적압연접합공정에 의해 제조된 초미세립 5052 알루미늄 합금의 상온 기계적 특성 및 미끄럼 마멸거동에 대한 연구)

  • 하종수;강석하;김용석;신동혁
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2003.03a
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    • pp.26-26
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    • 2003
  • 본 연구에서는 누적압연접합공정(ARB)을 통하여 5052 알루미늄 합금의 결정립을 약 0.2$\mu\textrm{m}$ 크기로 미세화 하였다. 누적압연에 의한 변형량 증가에 따른 미세 조직 변화와 결정립 간의 상대적인 방위각 차이를 TEM을 이용하여 관찰하였다. 누적 변형량을 함수로 상온 인장특성을 분석하였고, 초미세립 소재를 후속 열처리한 후 미세 조직 변화를 관찰하여 제조된 초미세립 소재의 열적 안정성을 평가하였다. 상온 대기 중에서 pin-on-disk 형태의 마멸시험기를 사용하여 초미세립 소재의 미끄럼 마멸시험을 변형량과 하중을 변수로 행하였다. 강소성 변형에 의해 제조된 5052 알루미늄 합금 소재의 마멸저항성은 강소성 변형 전과 비교하여 소재의 경도가 크게 증가하였음에도 불구하고 오히려 감소하였다. 마멸시험 후 마멸면의 SEM, 마멸단면의 OM 관찰과 마멸면 직하의 깊이에 따른 경도측정을 통하여 초미세립 소재의 마멸기구를 분석하였고 마멸표면의 변형 층을 관찰하였다. 또한 마멸면 직하 조직의 TEM 관찰을 통해서 마멸시험 중의 미세 조직 변화를 연구하였다.

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Al5052 Welding by $CO_2$ Laser using Filler Wire (용접 와이어를 사용한 Al5052 $CO_2$ 레이저 용접)

  • 박기영;이경돈;김주관
    • Laser Solutions
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    • v.5 no.1
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    • pp.13-21
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    • 2002
  • Compared to conventional welding process, laser welding does not use additional filler wire generally. However, if laser welding uses the filler wire, the applicability of the method can be broaden. When laser welding uses the filler wire, it is possible to enhance gap bridging ability and to prevent cracking in weld pool by metallurgical control. In this study, we had optimal condition and experimented gap bridging capability for butt welding with 2㎜ Al5052 alloys using the filler wire feeder. As the experimental parameters, wire feed rate and wire diameter are considered and then the performance of wire feed is evaluated under various filler wire welding conditions.

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A study on the through crack behavior of aluminum alloy with cantilever beam type under variable load (외팔보 형식의 하중진폭 변화에 대한 Al 합금의 관통균열 거동에 관한 연구)

  • Yoo, Heonil;Kim, Yeob-Rae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.22 no.4
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    • pp.834-842
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    • 1998
  • This paper examines the crack growth behavior of 7075-T651 and 5052-H32 aluminum alloy under high-low block loading condition. The cantilever beam type specimen with a chevron notch is used in this study. The crack growth and closure ae investigated by compliance method. The applied stress ratios are R=0.15, 0.0, -0.15 and R=-0.15, 0.0, 0.15. The crack growth rate was found to increase as the load amplitude increases. However,${\bigtriangleup}K_eff$ was almost independent on the stress ratio. The experimental constants of 7075-T651 and 5052-H32 in Paris law were c`=1-1.3${\times}{10^-7},m`=3~3.2 and c`=4~6{\times}{10^-9}, m`=4.3-4.8$, respectively. $K_op$ of 7075-T651 and 5052-H32 becomes smaller as the stress ratio decreases. It seems that the crack closure affects $K_op$.