The Al/Cu dissimilar metals were welded using the external heating assisted magnetic pulse welding technique, and a comparative analysis was conducted on the macroscopic morphology, interface structure, and mechanical properties of the welded joints under different external heating temperatures, namely room temperature, 100 ℃, and 200 ℃. The results demonstrate that the external heating assisted electromagnetic pulse welding technique can achieve high-quality welding of Al/Cu dissimilar metals. With increasing external heating temperature, the size of the effective bonding area of the welded joint increases. The wavy interface morphology exhibits different forms depending on the external heating temperature: at room temperature, the interface shows a mixed waveform of sine waves and shear waves; at 100 ℃, an irregular embedded waveform morphology is formed; at 200 ℃, the morphology is similar to that at room temperature, but the thickness of the interface reaction layer is maximum. Al-Cu compounds were detected in the interface reaction zones under all three conditions. The mechanical property test results indicate that as the external heating temperature increases, the mechanical performance of the welded joint gradually improves. When the heating temperature is 200 ℃, the tensile-shear strength of the welded joint reaches 4 076 N. All specimens fractured at the joint interface, exhibiting a mixed fracture morphology of "river-like" and ductile dimples, suggesting a ductile-brittle mixed fracture as the failure mode of the welded joint. Under the influence of the external heating, the increase in the effective bonding area of the welded joint and the changes in the interface waveform structure effectively enhance the mechanical properties of the joint.
magnetic pulse weldingexternal heating-assistedAl/Cu dissimilar metalsmicrostructuremechanical properties
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