Microstructure and properties of a shape memory alloy Ti-Ni-Al-V fabricated by double-wire arc additive manufacturing

In this study, a novel heterogeneous double-wire arc additive manufacturing method was used for the in-situ synthesis of a novel Ti-Ni-Al-V alloy wall. The results indicated that the synthesis wall was composed of the NiTi₂, B₂, and Ni₄Ti₃ phases from the bottom to the top. With an increase in deposition layers, the Ti2Ni content decreased. The hardness at the bottom was ∼685.4 HV_0.2, while that of the middle and stable regions was 553 HV_0.2. The maximum compressive strength was 2100 MPa. The fracture morphology was brittle. After cyclic compression, the recoverable and unrecoverable strains were 4.79 % and 1.21 %, respectively, indicating excellent recovery characteristics.