• Journal of Welding and Joining
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• 제34권4호
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• pp.34-39
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• 2016

Recently, aluminum alloy has used various industry, such as automobile, shipbuilding and aircraft because of characteristics of low density and high corrosion resistance. Al 6061-T6 is heat treatment materials so it has high strength and mostly used for assembly by mechanical fastening such as a bolting and riveting. In GMA (Gas Metal Arc) welding of alloy, some defects which are hot cracking, porosity, low-mechanical properties and large heat affected zone is generated, because of high heat conductivity. It reduces mechanical properties. In this study, the major factor effected on properties are analyzed after welding in Al 6061-T6 in GMAW, then optimize heat treatment conditions. Plate of Al 6061-T6 with a thickness of 12 mm is welded in V groove and applied welding method is butt joint. Mechanical properties and microstructure are analyzed according to heat treatment condition. Tensile strength, microstructure and Hardness are evaluated. Result of research appears that Al 6061-T6 applied heat treatment show outstanding mechanical properties.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2007년도 춘계학술대회 논문집
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• pp.639-640
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• 2007

• Journal of Advanced Marine Engineering and Technology
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• 제33권2호
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• pp.313-321
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• 2009

The construction of fiber-reinforced plastic (FRP) boats is decreasing trend since the application of international regulations on the control of marine environmental pollution, which recommended the use of environmentally friendly materials. The aluminum alloy used with material for ship is a superior to FRP. It is environmental friendly, easy to recycle, and provides a high added value to fishing boats. However, the welding for Al alloy materials have many problems, such as deformation by welding heat and effect of the working environment. In this paper, it was carried out welding by robot with welding material of ER5183 and ER5556 on 6061-T6 Al alloy for ship. The mechanical and electrochemical characteristics evaluated for specimen welded by robot. The cathodic polarization trend for the base metal and welding metal showed the effects of concentration polarization due to oxygen reduction and activation polarization due to hydrogen generation. The hardnesses of welding zone and heat affected zone are lower than that of base metal. At the result of tensile test, the specimen welded with ER5183 presented excellent property compared with ER5556.

• 한국표면공학회지
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• 제41권6호
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• pp.341-350
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• 2008

In friction stir welding for 6061-T6 with various traveling speed and rotation speed conditions, the best mechanical characteristics presented in traveling speed of 507 mm/min and rotation speed of 1100RPM. The maximum tensile strength and yield strength increased with the increasing of traveling speed. The result of the electrochemical characteristic evaluation in friction stir welding at optimum conditions for 6061-T6 Al alloy presented a good characteristics compare to base metal.

• Journal of Welding and Joining
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• 제17권2호
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• pp.44-52
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• 1999

This study deals with spot weld ability of dissimilar aluminum alloy sheets in order to take advantage of its lightweight and strength. The paper also shows the relationship between weld elements(i.e. current, welding time and tip force) and weld quality on the resistance spot weld part of the same and dissimilar Al alloy. The conclusions are: (1) Because of excessive tip force, deep indentation remained at the Al 5182 side which is lower stiffness at the dissimilar Al alloy. (2) Weld quality (i.e. tensile shear strength) of dissimilar Al alloy is superior to that of the same Al 6061 alloy. (3) As long cycles, fatigue life of spot weld specimen on dissimilar Al alloy sheets was better than that of the same Al alloy.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.148-152
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• 2000

The aluminum alloy 6061-T6 has been successfully used in structural applications especially the pressure vessel of the Advanced Neutron Source research reactor. And aluminum alloys, including 6061-T6, have a face-centered-cubic crystals structure. Under normal circumstances face-centered-cubic crystal structures do not exhibit cleavage fractures even at very lo9w temperatures. In aluminum-based structures, plates frequently find use as connecting links. Mechanical fasteners are often utilized in instances where ease of application, familiarity with fabrication processes, and severe dynamic loading are of concern. Plates frequently find use as connecting elements in structures built from aluminum alloys. Many structural elements employ mechanical fasteners. Twenty and twenty aluminum alloy 6061-T6 plates, representing four different bolt patterns, were mechanically deformed. And variable materials such as A1 6061-T6, Al 2024-T3, Carbon/Epoxy, Glass/Epoxy Composite and Woven fiber composite, are used as patch materials. From this experiment, it has been shown that the strength of patch-repaired specimens is different with the patch materials.

• Corrosion Science and Technology
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• 제18권6호
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• pp.292-299
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• 2019

The hull material of a high-speed ship may cause erosion damage from fluid impact. When physical erosion and electrochemical corrosion combine, erosion corrosion damage occurs. The aluminum ship is vulnerable to erosion corrosion because it can be operated at high speed. Thus, in this study, Al5052-O and Al6061-T6 aluminum alloys for the marine environment were selected as experimental materials. The erosion corrosion resistance of Al5052-O and Al6061-T6 aluminum alloys in seawater was investigated by an erosion test and potentiodynamic polarization test at the various flow rate (0 m/s, 5 m/s, 10 m/s, 15 m/s, 20 m/s). Erosion corrosion characteristics were evaluated by surface analysis, 3D analysis, SEM analysis, and the Tafel extrapolation method. The results of surface damage analysis after the erosion test showed that Al6061-T6 presented better erosion resistance than Al5052-O. The results of the potentiodynamic polarization test at the various flow rate, corrosion current density by Tafel extrapolation presented lower values of Al6061-T6 than Al5052-O. Al5052-O showed more surface damage than Al6061-T6 at all flow rates. Consequently, Al6061-T6 presented better erosion corrosion resistance than Al5052-O. The results of this study are valuable data for selecting hull material for an aluminum alloy vessel.

• 비파괴검사학회지
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• 제33권1호
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• pp.20-25
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• 2013

열화 정도를 예측하기 위한 비파괴기법으로 초음파기법이 널리 적용되고 있다. 초음파 속도와 감쇠 특성은 일반적으로 금속재료의 물성 변화에 따라 변화하기 때문에 초음파 속도와 감쇠 특성을 이용하여 금속재료의 열화 정도를 간접적으로 예측할 수 있다. 따라서, 본 연구에서는 반복하중으로 인하여 피로파괴 발생 가능성이 높은 볼트, 리벳 접합의 구조용재 및 선박 차량에 사용되고 있는 Al6061-T6을 피로수명의 0%, 55%, 70%, 85%인 시험편을 제작하였고, 가공된 시험편의 감쇠 특성을 이용하여 측정된 열화 이미지로 Al6061-T6의 건전부와 열화부를 판단하였으며, 건전부와 열화부의 감쇠 특성 차이를 계산하여 Al6061-T6의 열화 진행 정도를 평가하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제35권1호
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• pp.75-81
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• 2011

이종합금인 알루미늄 합금 6061-T6와 알루미늄 합금 5083-O의 용접을 위해 마찰교반 용접기술을 사용하였다. 마찰교반 용접된 이종 접합부에 대하여 기계적 특성, 경도 및 조직변화를 관찰하였다. 용접재의 기계적특성은 후진 측에 위치한 알루미늄 합금의 교반영역에 형성되는 미세조직이 주요한 변수로 작용하였다. 이종 알루미늄 합금이 교차한 양파 모양 형상의 얇은 층을 이루었다. 미세조직관찰에서 공구회전방향과 무관하게 이종합금 접합부에 기공이 관찰되지 않았으나 6061-T6 쪽 열영향부 영역에서 결정립 조대화기 뚜렷하였다. 본 논문의 연구결과, 결함이 없는 최상의 용접조건은 Al 6061-T6를 공구 진행방향에 전진 측에, Al 5083-O를 후진 측에 위치하고, 이송속도 124 mm/min, 1250 rpm의 공구의 회전수, 5 mm의 프루브 직경, 4.5 mm의 프루브 길이, 20 mm의 공구어깨, $2^{\circ}$의 공구 경사각 이다. 이때 용접재의 최대인장강도는 231 MPa이였고, 항복강도는 121 MPa을 나타내었다.

• 소성∙가공
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• 제16권6호
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• pp.443-446
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• 2007

The semi-solid process has been developed near net-shape components for kinds of methods. Thixo-forming with reheating prepared billet and rheo-forming with cooled melt until semi-solid state. Material is applied electromagnetic stirring system to slurry with aluminum 6061 alloy. An experiment has variation factors which are pressure, solid-fraction, stirring current and stirring time. The mechanical properties are compared to forge sample with to apply heat treatment T6. This study is researched function a virtual pressure and fine shape zone. Optimum pressure is found to prevent defect of porosity.