Developing Cu modified Ti6Al4V alloys with a combination of high strength and ductility by electron beam freeform fabrication

A thin-wall structure of Ti6Al4V-3Cu was prepared by electron beam freeform fabrication (EBF3) with Cu plated wire and a novel in-situ alloying method based on chemical plating for wire-based additive manufacturing was proposed. The results show that the addition of Cu leads to significant refinement of prior-beta grain, resulting in the transformation from fully columnar to mixed equiaxed-columnar structure. Meanwhile Ti2Cu precipitates are formed to play a role in strengthening. The average ultimate tensile strength of Cu modified specimens increases about 170 MPa in both horizontal and vertical directions compared to those without Cu whereas the plasticity does not decrease obviously. With the addition of Cu, the mechanical properties of the EBF3 Ti6Al4V alloy tend to be a favorable combination of strength and ductility.

Automated summary

A thin-wall structure of Ti6Al4V-3Cu was prepared using electron beam freeform fabrication (EBF3) with Cu plated wire and a novel in-situ alloying method. The addition of Cu led to significant refinement of prior-beta grain, resulting in improved strength without significant decrease in ductility.