• Journal of Advanced Marine Engineering and Technology
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• v.35 no.1
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• pp.75-81
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• 2011

Dissimilar joining of aluminum 6061-T6 alloy to aluminum 5083-O alloy was performed using friction-stir welding technique. The mechanical properties, hardness, macro- and micro-structure on dissimilar friction-stir-weld aluminium alloy were investigated. Mechanical properties of the weld mainly depend on which Al alloy is placed at the retreating sides of the rotating tool respectively during dissimilar friction-stir weld because the microstructure of stir zone was mainly composed of welded Al alloys of the retreating side. Onion ring pattern was observed like lamella structure stacked by each Al alloy in turn. It apparently results in defect-free weld zone that traverse speed was changed to 124 mm/min under conditions of tool rotation speed like 1250 rpm with 5 mm of tool's prove diameter, 4.5 mm of prove length, 20 mm of shoulder diameter, and $2^{\circ}$ of tilting angle. The 231 MPa of ultimate stress and the 121 MPa of yield point are obtained about the friction-stir-welded Al 6061-T6(AS) to Al 5083-O(RS).

• Transactions of Materials Processing
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• v.7 no.5
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• pp.450-458
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• 1998

The high temperature deformation behavior of Al 5083 alloy has been studied in the temperature range of 350 to 520 ${\circ}C$ and strain rate range of 0.2 to 3.0/sec by torsion test. The strain rate sensitivity(m) of the material was evaluated and used for estabilishing power dissipation maps following the dynamic material model. These maps show the variation of efficiency of power dissipation(${\eta}$=2m/(2m+1)) with temperature and strain rate. Hot restoration of dynamic recrystallization (DRX) was analyzed from the flow curve, deformed microstructure, and processing maps during hot deformation. Also, the effect of deformation strain on the efficiency of power dissipation of the alloy was analysed using the processing maps. Moreover relationship between the hot-ductility and efficiency of power dissipation of the alloy depending on thmperature and strain rate was studied using the Zener-Hollomon parameter(Z=${\varepsilon}$exp(Q/RT) It is found that the maximum efficiency of power dissipation for DRX in Al 5083 alloy is about 74.6 pct at the strain of 0.2. The strain rate and temperature at which the efficiency peak occurred in the DRX domain is found to be ∼0.1/sec and ∼450${\circ}C$ respectively.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.9
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• pp.57-62
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• 2021

CNC machining is used to fabricate various components. This has led to the development of processing-based industries for the production of automobile, appliances, semiconductors, and rockets. Additionally, this machining has enabled economical mass production of high-quality products in industries. Magnesium alloy with a hexagonal closed packed configuration is prone to difficulties during plastic machining, has a high oxygen affinity, and exhibits poor corrosion resistance to seawater and the atmosphere. In this research, Al alloy A5083 was used to investigate and analyze the surface roughness with a certain depth of cut fixed by the machining center (DVM-500II) and various feed rates, speeds, and processing methods after modeling and simulated machining with Gibbs CAM.

• Journal of Welding and Joining
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• v.30 no.4
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• pp.4-9
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• 2012

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.137-137
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• 2017

Al-Mg 합금은 비중이 적고 강도가 우수하기 때문에 해양 환경에서 구조용 재료로 많이 사용되고 있으며, 특히 선박용 재료로 사용될 경우 선체의 중량을 줄일 수 있어 연료비가 절감되며 선속의 고속화가 가능하다. 그러나 해양환경에서의 재료 특성에 관한 지식 및 관련 기술 부족으로 알루미늄 선박 건조는 활성화 되지 못하고 있는 실정이다. 알루미늄 합금은 공기 중에서는 우수한 내식성을 지니는 것으로 알려져 있으나 해수환경에서는 염소이온에 의한 부동태 피막 파괴로 인해 내식성이 저하되며 공식 및 응력부식균열 등에 의한 손상이 발생할 수 있다. 특히 용접부의 경우, 모재에 비해 부식손상에 취약하며 기공과 같은 용접 결함을 포함하고 있어 구조물 파괴의 시발점이 될 수 있으므로 선박 및 구조물 건조시 대비가 필요하다. 그러나 이에 관한 충분한 연구가 이루어지지 않아 국내 중소형 조선소의 경우 알루미늄 선박 건조에 어려움을 겪는 경우가 많다. 따라서 본 연구에서는 선박 건조 및 해양 구조물에 널리 사용되는 Al 5083-H321 합금 용접부에 대하여 해수 내 부식 특성을 연구하고자 한다. 부식특성 파악을 위한 전기화학적 실험에 앞서 화학적 에칭을 통해 미세부위별 실험을 수행하였다. 기준전극은 은/염화은 전극을 대극은 백금전극을 사용하였으며, 타펠 분석을 위한 분극실험은 OCP를 기준으로 -0.25 ~ +0.25 V까지 실시하였고 양극분극실험은 OCP ~ +3.0 V까지 실시하였다. 양극분극 실험 후 부식된 표면은 주사전자현미경과 3D 분석을 통해 용접부 조직에 따른 전기화학적 특성을 관찰하였다.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.8
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• pp.974-980
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• 2014

Aluminum acts as sacrificial anode and corrosion protection with Al2O3 formation. If the same current on material for Al ships with steel ships supplies, the more hydrogen would be occurred, that result is bring about over-protection. For this reason, the damage by hydrogen embrittlement leads to the serious accident. In this study, we evaluate electrochemical behavior with rotation speed of 5083-H116 Al alloy material for Al ship in seawater. To examine the electrochemical characteristics with rotation speed and its effects on performance, experiments were conducted at four rotation speed. Results of experiments, the corrosion current density and damage were increased by applying the rotation speed compared to static state.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2011.06a
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• pp.321-321
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• 2011

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.97-98
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• 2006

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.295-296
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• 2006

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2012.06a
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• pp.252-252
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• 2012