Microstructure and mechanical properties of a novel Ti-Cu alloy fabricated using dual-wire arc additive manufacturing

With the increase in material requirements in the aerospace sector, conventional Ti alloys cannot fully satisfy the stringent demands of critical structural components. Consequently, the development of novel high-property Ti alloys has become an urgent challenge. Dual-wire arc additive manufacturing (D-WAAM) is a promising method for designing such advanced alloys owing to its high deposition efficiency and compositional tunability. In this study, pure Ti and Cu welding wires were selected as the feedstock materials, and Ti- x Cu alloys ( x = 5, 8, and 15 at%) were fabricated via D-WAAM. The results revealed that increasing the Cu content promoted a transition from lath-like α-Ti structures to clustered microstructures rich in Ti 2 Cu phases. Correspondingly, the microhardness increased from 257 to 323 HV 0.2 , and the ultimate tensile strength increased from 432 to 929 MPa. Moreover, the fracture mode changed from ductile to brittle. Electrochemical tests further showed that the addition of Cu increased the corrosion potential and elevated the charge-transfer resistance to the order of 10 6 Ω, indicating a corrosion resistance superior to that of commercially pure Ti.