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Abstract
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The effect of friction stir welding (FSW) parameters on the microstructure, mechanical and
electrical properties of 2024 aluminum alloy and copper joints was investigated. After
obtaining the processing window, the optimum values of ultimate tensile strengthz
142 MPa, elongationz 5 %, and electrical resistivityz 33 nUm were obtained by FSW at a
rotational speed (W) z 948 rpm and a traverse speed (V) z 85 mm/min. W/V ratio, which
stands for the amount of heat input during FSW, had a considerable effect on the joints'
properties. At W/V>(W/V)optimum, larger amounts of Al4Cu9 and Al2Cu brittle intermetallic
compounds (IMCs), and at W/V<(W/V)optimum, more defects were formed in the joints
compared to optimum condition. IMCS and voids in the non-optimum joints were the
origin of lower strength and ductility and higher electrical resistivity. Moreover, the
mechanism of microstructure formation in the stir zone is discussed in detail.
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