• Title/Summary/Keyword: Dissimilar Friction Stir Welding

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Effects of Tool Plunge Position on Mechanical Properties of Friction-stir-weleded Region in A6061-T6/AZ31 Dissimilar Metals (A6061-T6/AZ31 이종금속 마찰교반접합부의 기계적 특성에 미치는 툴 삽입 위치의 영향)

  • Lee, Kwang-Jin;Kim, Sang-Hyuk
    • Journal of Welding and Joining
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    • v.30 no.5
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    • pp.22-26
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    • 2012
  • Butt-joints of A6061-T6 and AZ31 plates were successfully manufactured by using a friction stir welding method. Off-set free joints and off-set joints were fabricated to investigate the effect of the tool plunge position on the mechanical properties of the joints. Hardness test, tensile test and charpy impact test was performed to evaluate the mechanical properties of the joints. Off-set condition resulted in increase of mechanical properties of the joints. The variation of the hardness distribution in the SZ was also stabilized in the off-set condition. Tensile strength of the off-set joint was about 85% against to that of the AZ31 base metal. Impact absorption energy by Charpy-Impact-Test of the off-set joint also increased by almost 2 times against to that of the AZ31 base metal.

Corrosion Properties of Dissimilar Friction Stir Welded 6061 Aluminum and HT590 Steel

  • Seo, Bosung;Song, Kuk Hyun;Park, Kwangsuk
    • Metals and materials international
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    • v.24 no.6
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    • pp.1232-1240
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    • 2018
  • Corrosion properties of dissimilar friction stir welded 6061 aluminum and HT590 steel were investigated to understand effects of galvanic corrosion. As cathode when coupled, HT590 was cathodically protected. However, the passivation of AA6061 made the aluminum alloy cathode temporarily, which leaded to corrosion of HT590. From the EIS analysis showing Warburg diffusion plot in Nyquist plots, it can be inferred that the stable passivation layer was formed on AA6061. However, the weld as well as HT590 did not show Warburg diffusion plot in Nyquist plots, suggesting that there was no barrier for corrosion or even if it exists, the barrier had no function for preventing and/or retarding charge transport through the passivation layer. The open circuit potential measurements showed that the potential of the weld was similar to that of HT590, which lied in the pitting region for AA6061, making the aluminum alloy part of the weld keep corrosion state. That resulted in the cracked oxide film on AA6061 of the weld, which could not play a role of corrosion barrier.

Joint characteristics of dissimilar formed Al alloys with fixed location of welded specimen by friction stir welding (접합시편의 고정위치에 따른 이종 알루미늄 합금의 마찰교반접합부특성)

  • 이원배;김종웅;연윤모;정승부
    • Proceedings of the KWS Conference
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    • 2003.05a
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    • pp.176-178
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    • 2003
  • The weld zone of dissimilar formed Al alloy exhibited the complex structure of the two materials and mainly composed of the retreating side material. The mechanical properties were also depended on the dominant microstructure of the weld zone with welding conditions. The different mechanical properties of weld zone with welding conditions were related to the behavior of the precipitates of wrought Al alloy and Si particles of cast Al alloy. The higher mechanical properties of weld were acquired when relatively harder material, wrought Al alloy, was fixed at the retreating side.

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A Study on the Effect of Metal Plate Position Design on Mechanical Strength during Lap Joint Dissimilar Friction Stir Welding Process of Aluminum Alloys (알루미늄 합금의 이종겹치기 마찰교반용접시 판재의 위치설계가 기계적 강도에 미치는 영향에 관한 연구)

  • Park, Hee-Sang;Ko, Jun-Bin;Choi, Won-Doo;Choi, Man-Young
    • Journal of the Korean Society for Precision Engineering
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    • v.27 no.3
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    • pp.66-72
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    • 2010
  • Recently, the use of means of transportation of the lightweight aluminum to temper the trend is increasing. More efficient use of lightweight aluminum material to Friction stir welding has been widely attempted. Types of welding tools at the right screw to rotate anti-clockwise direction, when the tensile stress exerted on the location of the top plate to the left in the direction of the welding process to the installation was able to obtain high tensile strength. A5052 to the top of the left in the direction of the welding process to install and, when you installed the right under the A6061 was not easily come up to the top of the A5052. Conversely, at the bottom left to install on top of the A6061 and A5052 have been installed at the bottom of the upper area of the A6061 and A5052 intrude easily form the shape of the hill you can see that it was formed.

Fatigue Crack Growth Properties of Friction Stir Welded Dissimilar Aluminum Alloys (이종알루미늄합금 FSW 접합부의 피로균열진전 특성)

  • Lee, Won-Jun;Lee, Hyo-Jae;Kim, Hyung-Jin;Park, Won-Jo
    • Journal of Ocean Engineering and Technology
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    • v.27 no.1
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    • pp.37-42
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    • 2013
  • The presence of a crack can increase the local stress or strain, which can cause inelastic deformation and significantly reduce the life of a component or structure. Therefore, in this study, the fatigue crack growth (FCG) behaviors of friction stir welded Al 2024-T3 and Al 7075-T6 specimens were examined, with fatigue cracks growing parallel to the dynamically recrystallized zone at variable ${\Delta}K$ values and an R ratio of 0.3. In addition, the FCG values of the base metal Al 2024-T3 and Al 7075-T6 were tested under the same conditions and parameters as comparative groups. The results showed that compared with the base metal Al 2024 specimen, which had the best fatigue property, the welded specimen had only 88% of the fatigue cycles.

A Study on the Weldability and Mechanical Characteristics of Dissimilar Materials Butt Joints by Laser Assisted Friction Stir Welding (Laser-FSW Hybrid 접합기술을 적용한 이종재료(Al6061-T6/SS400) 접합부의 접합성 및 기계적 특성에 관한 연구)

  • Bang, Han-Sur;Bang, Hee-Seon;Kim, Hyun-Su;Kim, Jun-Hyung;Oh, Ik-Hyun;Ro, Chan-Seung
    • Journal of Welding and Joining
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    • v.28 no.6
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    • pp.70-75
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    • 2010
  • This study intends to investigate the weldability and mechanical characteristics of butt weld joints by LAFSW for dissimilar materials (Al6061-T6 and SS400). At optimum welding conditions, the tensile strength of dissimilar materials joints made by FSW is found to be lower than that of LAFSW. Due to the increase in plastic flow and formation of finer recrystallized grains at the TMAZ and SZ by laser preheating in LAFSW, the hardness in LAFSW appeared to be higher than that of FSW. Compared with FSW, finer grain size is observed and elongated grains in parent metal are deformed in the same direction around the nugget zone in TMAZ of Al6061-T6 by LAFSW. Whereas, at weld nugget zone, coarse grain size is appeared in LAFSW compared to FSW, which is owing to more plastic flow due to laser preheating effect. In dissimilar materials joints by LAFSW, ductile mode of fracture is found to occur at Al6061 side with fewer brittle particles. Mixed mode of cleavage area and ductile fracture is observed at SS400 side.

Microstructural and Mechanical Analysis of a Friction Stir Welded Joint of Dissimilar Advanced High-Strength Steels (초고강도 합금강의 이종마찰교반 접합부에서의 미세조직 특성 및 기계적 물성 연구)

  • Lee, J.W.;Cho, H.H.;Mondal, Mounarik;Das, Hrishikesh;Hong, S.T.
    • Transactions of Materials Processing
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    • v.29 no.1
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    • pp.11-19
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    • 2020
  • For microstructural analysis of a friction stir welded (FSWed) joint of advanced high-strength steels, dual phase (DP) and complex phase (CP) steels, are studied. FSWed joints are successfully fabricated in the following four cases: (i) DP/DP; (ii) CP/CP; (iii) DP/CP, where the advancing side is DP and the retreating side is CP; (iv) CP/DP, where the advancing side is CP and the retreating side is DP. The stir zone (SZ) of (i) the DP/DP joint mainly consists of lath martensite, while the stir zone of (ii) the CP/CP joint consists not only of lath martensite but also of bainite. In the case of (iii) DP/CP and (iv) CP/DP, they exhibit a similar microstructure including acicular-shaped phases in the joints; however, cross-sections of the joints show differences in material mixing in each case. In (iv) the CP/DP joint, temperature towards the CP steel is sufficient to cause softening, thus leading to better mixing than that in (iii) DP/CP. The phases of the SZ in each of the four cases are formed by phase transformation during the FSWed process; however, the transformed phase volume fraction of CP steel is lower than that of DP steel, indicating that dynamic recrystallization occurs mainly in CP steel. The hardness values of the SZ are significantly higher than those of the base materials, especially, the SZ of (iii) the DP/CP joint has the highest value due to highest fraction of lath martensite.