Microstructure and mechanical properties of laser welded titanium alloy and stainless steel joint with composite interlayer

Abstract In this work, TA2/T2 was used as a composite interlayer to prevent the formation of brittle Ti-Fe intermetallics when joining TC4 Ti alloy to 304 stainless steel. The TA2/T2 (commercially pure Ti and Cu) 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 the TC4-TA2 interface, a weld zone was formed due to the mixing of molten TC4 and TA2. The laser was also focused on the T2-304 stainless steel interface, a weld zone was formed due to the mixing of molten T2 and 304 stainless steel. Composite interlayer TA/T2 was used not only to prevent the formation of Ti-Fe intermetallics during welding but also to improve microstructure and properties of the stainless steel–Ti alloy joint. The joint fractured at the TA2/T2 explosive welding interface with a maximum tensile strength of 428 MPa.