Microstructure and Mechanical Property Improvement of Dissimilar Metal Joints for TC4 Ti Alloy to 304 Stainless Steel Using TA2/Q235 Composite Interlayer

Abstract

In this work, TA2/Q235 was used as an composite interlayer to prevent the formation of these brittle Ti–Fe intermetallics when joining TC4 Ti alloy to 304 stainless steel (SS). The TA2/Q235 composite interlayer was prepared by explosive welding. The laser was focused on the TC4–TA2 interface, which joined the TC4 and TA2 by fusion welding. At TC4–TA2 interface, a weld zone was formed due to the mixing of molten TC4 and TA2. The laser was focused on the Q235–304 SS interface, a weld zone was formed due to the mixing of molten Q235 and 304 SS. Composite interlayer TA/Q235 was used to prevent the formation of Ti–Fe intermetallics during welding and improve microstructure and properties of the SS–Ti alloy joint. The joint fractured at the TA2/Q235 explosive welding interface with the maximum tensile strength of 548 MPa.