Combined titanium-steel structures formation by directed energy deposition using vanadium and nickel interlayers

The possibility of obtaining a combined titanium-steel construction by directed energy deposition using vanadium or vanadium/nickel interlayers has been investigated. Vanadium wire VnPr-1, nickel wire NP1 grade, and welding wires Sv-08G2S, 316L, and MSG NiFe-1 grades were used for deposition on the end of the titanium plate VT1-0. The use of vanadium as an interlayer deposited on titanium makes it possible to provide a joining with a stable structure, steady hardness distribution, and acceptable manufacturability. The content of dissolved titanium in the vanadium layer has a negative effect on the subsequent deposition of steel, nickel, or iron-nickel alloy. Therefore, the titanium content was reduced to a level of less than 0.5% by the deposition of at least 4 vanadium beads. The results of tensile tests demonstrated that all specimens failed in the elastic section mostly along the interlayers between vanadium and subsequent layers of low-carbon steel, nickel, and iron-nickel alloys deposited on it. The greatest ultimate tensile strength is achieved in the specimen, which is a compound of titanium and steel through interlayers of vanadium and iron-nickel alloy, and constitutes 251 MPa. The only specimen was destroyed along the titanium-vanadium interlayer probably due to brittle ω–phase formation.