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چکیده
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In the present study, AZ31 magnesium alloy was bonded to 7075 aluminum alloy at various temperatures (393, 402, 412, and 421 °C) and at different holding times ( 25, 60, and 120 min) through diffusion bonding. Besides, 12, 29, 38, and 80 MPa axial loads accompanied by vacuum condition were applied during the bonding. The experimental and numerical results of the successful joints confirmed the existence of the different reacted layers in the diffusion zone and the formation of the predicted intermetallic compounds. Findings show that by applying 29 MPa pressure, at 402, 412, and 421 °C temperatures, the interfacial transition zone (ITZ) with 21.26, 21.96 and 22.60 μm thicknesses was respectively formed. Besides, the maximum amount of the bond strength (30 MPa) due to the proper coalescence of metal surfaces occurred at 402 °C. While the hardness of ITZ was found to be greater than base metals, it was by increasing the bonding temperature that the amount of this layer hardness also increased. Moreover, the results of simulation with DEFORM-3D software indicated that the ITZ had different mechanical properties from base metals and it was also revealed that, by analyzing the effective stress the Mg alloy specimen was more deformed than Al alloy during the joining process.
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