Microstructure and mechanical properties of resistance spot welded AZ31/AA5754 using a nickel interlayer

Dissimilar joining of aluminum (AA5754) and magnesium (AZ31) alloys was investigated in the current study via resistance spot welding. A commercial pure nickel interlayer was inserted between the two base metals to prevent the formation of Al–Mg intermetallic compounds. Microstructural investigations, via SEM/EDS and XRD methods, were carried out to characterize the Mg/Ni and Al/Ni interfaces. It was found that the Al–Mg reaction was …