Mechanical properties and joining mechanism of magnetic pulse welding of aluminum and titanium

Aluminum–titanium hybrid parts provide different performance advantages and realize performance complementarity that can be applied in aerospace and automobile applications. However, aluminum joined to titanium by fusion welding presents challenges in achieving good joint quality. This study investigated the joining of aluminum to titanium by magnetic pulse welding, a solid-state process with excellent advantages for joining dissimilar materials. The influence of discharge voltage, radial gap, and overlap length on joint quality was studied. The joint with the highest shear strength was obtained with a 10 mm overlap length, 6.5 kV discharge voltage, and 2 mm radial gap. Joints with overlap lengths below 6 mm have the highest effective joining ratio. The overlap length affects the impact mode of the joint, and three impact modes were proposed: bidirectional, overall, and single-orientation impact. The single-orientation impact mode has the highest effective joining ratio. Finally, investigations revealed that the pulse-welded joint is a composite bond consisting of mechanical and metallurgical bonding with waves and intermetallic compounds as two of its important characteristics.