Microstructure and tensile properties of Ti6Al4V with Layered Structures fabricated by Electron Beam Directed Energy Deposition

Adding modified elements to regulate the microstructure of titanium alloys prepared by additive manufacturing and enhance the mechanical properties of as-deposited titanium alloys has become a research focus. However, this approach also brings the risk of causing the materials with high strength-low plasticity characteristics. In this study, a macroscopic layered structure titanium alloy with hierarchical heterogeneous characteristics was constructed by alternately melting Ti6Al4V wire and Cu-modified Ti6Al4V wire using electron beam as a heat source. The tensile test results demonstrated that the layered structure titanium alloy exhibiting great strength and plasticity matching, which proved that the layered structure constructed via additive manufacturing could effectively alleviate the strength-ductility trade-off. The mechanism of synergistical improvement of the fracture strength and plastic was attributed to the deformation-induced strengthening as well as multiple crack-deflection and tip-passivation occurring during the plastic deformation of layered Ti6Al4V alloy.