Study on the Microstructure and Properties of Titanium/Aluminum Continuous Drive Friction Welded Joints

In this study, a continuous drive friction welding method was utilized to join TC4 titanium alloy and 6061 aluminum alloy round bars. The effects of friction time on interfacial microstructures, mechanical properties, and corrosion resistance of Al-Ti joints were analyzed systematically. The results indicate that the flying edge on the Al side of the joint gradually increases with an increase in friction time. The scanning electron microscope morphology of the joint and the sudden change in joint hardness indicate that the intermetallic compounds (IMCs) with different morphology and sizes were formed at the interface. EDS analysis and XRD analysis of the tensile fracture surface showed that these IMCs were mainly the TiAl3 phase. Short friction times resulted in the mainly intermittent granular and massive distribution of IMCs and weak joining strength with the substrate. Prolonged friction times led to the formation of more continuous laminated IMCs at the joint interface, and the overgrowth of IMCs was detrimental to joint performance, which finally increased then decreased in tensile strength and corrosion resistance of the joints.