Fatigue Performance of Titanium–Aluminum–Vanadium Alloy Fabricated by Laser-Wire-Based Directed Energy Deposition Forming Dot-Shaped Beads

Abstract

Laser-wire-based directed energy deposition (DED) is a type of additive manufacturing. We investigated the chemical composition and fatigue performance to verify the usefulness of Ti–6Al–4V fabricated by laser-wire-based DED which deposited dot-shaped beads on a base material and conducted in preventing atmospheric intrusion with local shielding only. We compared the fatigue performance to a wrought material equivalent to AMS4967M and evaluated the deposited material in the as-fabricated condition. The chemical composition of the deposited material was within the specifications for the alloy. The fatigue strength at 1 × 10⁷ cycles of the deposited material was more than 100 MPa higher than that of 682 MPa of the wrought material. Perhaps the high fatigue strength of the deposited material was caused by the low porosity and the acicular α′ martensitic phase. From these results, we showed the usefulness of Ti–6Al–4V deposited by a laser-wire-based DED to which local shielding was applied.