Effect of deposition sequence on interfacial characteristics of Inconel–copper functional bimetallic structures fabricated by directed energy deposition-arc

Interfacial bonding reliability is a critical issue in bimetallic structures. To understand the effect of deposition sequence on interfacial characteristics, bimetallic structures of Inconel and copper alloys were fabricated by directed energy deposition arc (DED-Arc). The interfacial element diffusion behaviors and formation mechanisms were investigated in detail. The bimetallic structure of C18150 on GH4169 exhibits a sound metallurgical bonding interface with a wide interfacial region (∼400 μm), which is attributed to Marangoni convection and intense elemental interdiffusion. The study highlights the feasibility of fabricating large Inconel–copper functional bimetallic structures with sound metallurgical bonding using DED-Arc and it provides a theoretical reference for design and fabrication of bimetallic structures with material-property mismatches.