Effect of Titanium and Titanium Nickelide Substrates on the Structural-Phase State and Mechanical Properties of Electron Beam Additive Manufacturing TiNi-Based Alloys

We investigated the structural-phase state and mechanical properties of a TiNi-based alloy, obtained by electron beam wire-feed additive manufacturing on titanium and titanium nickelide substrates. It was shown that the printed samples have a heterogeneous coarse-grained microstructure. At room temperature, the obtained samples have the structure of the high-temperature B2-phase of TiNi and the secondary Ti2Ni (or Ti4Ni2Ox) phase. It was found that the printed samples on the Grade 2 substrate failed brittlely during testing. The printed samples on Ti49.8Ni50.2 (at %) substrate were plastically deformed and demonstrated pseudoelasticity plateau. It is shown that the value of mechanical properties correlates with the content of Ti2Ni (or Ti4Ni2Ox).