Functional and Mechanical Properties of As-Deposited and Heat Treated WAAM-Built NiTi Shape-Memory Alloy

In this work, MIG process was utilized for the wire arc additive manufacturing of wall-shaped parts, using NiTi shape-memory alloy. High-scale specimens consisting 20 layers were deposited by Ni-rich (Ni55.56Ti wt.%) as a feedstock on substrate with identical chemical composition. One two heat-treated at temperature 430 °C 1 h. The influence such heat treatment microstructure, phase transformation temperatures, and compositions, microhardness, tensile bending tests’ results is discussed. As-deposited metal successfully demonstrates superelastic behavior, except in lower zone. regard to effect, it concluded that both as-deposited samples deformed liquid nitrogen completely restored (100%) their shapes an initial strain 4–5%. An occurrence R-phase found specimens. tests be anisotropic along height presented led changes functional mechanical properties specimen, provided formation finely dispersed Ni4Ti3, NiTi2, Ni3Ti phases.