Anisotropic characterization of wire-arc additive manufacturing Ti-5Al-2Sn-2Zr-4Mo-4Cr alloy: Influence of texture and microstructure

The microstructure, monotonic tensile, low cyclic fatigue (LCF) behavior, and failure mechanisms of wire-arc additive manufacturing (WAAM) TC17 alloy were investigated to guide the design of aviation industry components. The results showed that the average elongation of horizontal and vertical samples was 6.4 % and 14.5 %, respectively. The total strain amplitudes of horizontal and vertical samples were 1.207 % and 1.908 %, respectively, at 2N_f = 10³. The α_GB and {0001}<11–20> slip system together provide the cumulative plastic deformation, resulting in lower plasticity of horizontal loading compared to vertical loading. Based on crystallography, a parameter F∗ was proposed to quantify the anisotropy of LCF properties and the strong correlation between crack propagation and the α + β microstructure. By controlling the deposition parameters in WAAM, it is possible to achieve the desired α lamellae orientation (∼45°< θ < ∼90°), ensuring superior fatigue resistance in the vertical loading direction.