• Journal of Welding and Joining
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• v.28 no.5
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• pp.15-19
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• 2010

• Proceedings of the KWS Conference
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• 2003.05a
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• pp.57-59
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• 2003

• Journal of Powder Materials
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• v.31 no.1
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• pp.37-42
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• 2024

Friction stir spot welding (FSSW) is a solid-state joining process and a rapidly growing dissimilar material welding technology for joining metallic alloys in the automotive industry. Welding tool shape and process conditions must be appropriately controlled to obtain high bonding characteristics. In this study, FSSW is performed on dissimilar materials AA5052-H32 aluminum alloy sheet and SPRC440 steel sheet, and the influence of the shape of joining tool and tool insertion depth during joining is investigated. A new intermetallic compound is produced at the aluminum and steel sheets joint. When the insertion depth of the tool is insufficient, the intermetallic compound between the two sheets did not form uniformly. As the insertion depth increased, the intermetallic compound layer become uniform and continuous. The joint specimen shows higher values of tensile shear load as the diameter and insertion depth of the tool increase. This shows that the uniform formation of the intermetallic compound strengthens the bonding force between the joining specimens and increases the tensile shear load.

• Korean Journal of Materials Research
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• v.27 no.6
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• pp.331-338
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• 2017

This study was carried out to investigate the optimum condition of a friction stir welding process for a joint of AA2219-T87 and AA2195-T8 dissimilar aluminum alloys. These alloys are known to have good cryogenic properties, and as such to be suitable for use in fuel tanks of space vehicles. The welding parameters include the travelling speed, rotation speed and rotation direction of the tool. The experiment was conducted under conditions in which the travelling speed of the tool was 120-300 mm/min and the rotation speed of the tool was 400-800 rpm. To investigate the effect of the rotation direction of the tool, the joining was performed by switching the positions of the two dissimilar alloys. After welding, the microstructure was observed and the micro-hardness were measured; non-destructive evaluation was carried out to perform tensile tests on defect-free specimens. The result was that the microstructure of the weld joint underwent dynamic recrystallization due to sufficient deformation and frictional heat. The travelling speed of the tool had little effect on the properties of the joint, but the properties of the joint varied with the rotation speed of the tool. The conditions for the best joining properties were 600 rpm and 180-240 mm/min when the AA2219-T8 alloy was on the retreating side(RS).

• Proceedings of the KWS Conference
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• 2005.11a
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• pp.189-191
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• 2005

Dissimilar joining of AI 6013-T4 alloys and austenite stainless steel was carried out using friction stir welding technique. Microstructures near the weld zone and mechanical properties of the joint have been investigated. Microstructures in the stainless steel side and AI alloy were depended on the thermo-mechanical condition which they received. TEM micrographs revealed that the interface region was composed of the mixed layers of elongated stainless steel and ultra-fine grained AI alloy and intermetallic compound layer which was identified as the $Al_{4}Fe$ with hexagonal close packed structure. Mechanical properties were lower than those of 6013 AI alloy base metal, because tool inserting location was deviated to AI alloy from the butt line, which resulted in the lack of the stirring.

• Proceedings of the KWS Conference
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• 2003.11a
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• pp.265-267
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• 2003

• Proceedings of the KWS Conference
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• 2003.05a
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• pp.72-74
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• 2003

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.7-13
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• 2019

This study aims to develop a FE Model to simulate dissimilar friction stir welding and to address its potential for fundamental analysis and practical applications. The FE model is based on Coupled Eulerian-Lagrangian approach. Multiphysics systems are calculated using explicit time integration algorithm, and heat generations by friction and inelastic heat conversion as well as heat transfer through the bottom surface are included. Using the developed model, friction stir welding between an Al6061T6 plate and an AZ61 plate were simulated. Three simulations are carried out varying the welding parameters. The model is capable of predicting the temperature and plastic strain fields and the distribution of void. The simulation results showed that temperature was generally greater in Mg plates and that, as a rotation speed increase, not the maximum temperature of Mg plate increased, but did the temperature of Al plate. In addition, the model could predict flash defects, however, the prediction of void near the welding tool was not satisfactory. Since the model includes the complex physics closely occurring during FSW, the model possibly analyze a lot of phenomena hard to discovered by experiments. However, practical applications may be limited due to huge simulation time.

• Proceedings of the KWS Conference
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• 2006.10a
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• pp.112-114
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• 2006

• Journal of Welding and Joining
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• v.24 no.4
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• pp.6-10
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• 2006