The microstructure and properties of Cu-Ta alloys prepared by laser directed energy deposition

The Cu-Ta and Cu-Ta-Ti deposited alloys were successfully prepared by laser directed energy deposition. The occurrence of monotectic reaction in Cu-Ta alloy was evidenced under the condition of oxygen impurities and high cooling rate. The incorporation of Ti in Cu-Ta-Ti alloy promotes the transition from incoherent Cu/Ta interface to semi-coherent Cu/β-Cu₃Ti/Ta interface, facilitating the dislocations transmit across the interface. Additionally, the solid solution strengthening and the precipitation strengthening provide the Cu-Ta-Ti deposited alloy with a balance of excellent strength and ductility, where the Cu-Ta-Ti deposited alloy has an ultimate tensile strength of 744 ± 8 MPa, a yield strength of 577 ± 12 MPa, and a total elongation of 9.9 ± 0.3 %.