LAUSR

The dissimilar welding of Al–Zn–Mg alloy (7005) plates and Al–Mg alloy (5083) rods was conducted using the inertia friction welding process. The effect of rotational speed during welding on the microstructure and mechanical properties of the joints was then investigated. The results indicate that under lower rotational speeds, a transition layer was formed at the interface that reduced the tensile strength of the joint. However, dynamic recrystallization occurred in the region near the interface resulting in excellent grain refinement and good metallurgical bonding. The tensile strength of the joints increased with increasing rotational speed due to the extrusion of the transition layer under higher rotational speeds. A maximum tensile strength of 311.4 MPa, approximately 88% of the 5083 base metal tensile strength, was achieved using a rotational speed of 3000 rpm. All tensile specimens manufactured at lower rotational speeds failed along the interface between base metal and weld. However, the peripheral zone of the tensile specimens manufactured at 3000 rpm fractured in the thermo-mechanically affected zone of the 5083 alloy via a quasi-cleavage fracturing mode. The results of this study are expected to be useful in improving the quality of dissimilar aluminum alloy welds.