PSI - Issue 68

Mohamed Elsayed et al. / Procedia Structural Integrity 68 (2025) 1003–1009 Elsayed et al. / Structural Integrity Procedia 00 (2025) 000–000

1005

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Fig. 1. (a) Schematic drawing of the 3D plates during printing process and (b) scanning strategy with 60 o rotational, magnified with blue dashed lines. 1.2. Welding processes 1.1.1. GTAW technique The GTAW technique was used to join the 3D-printed plates with a butt joint, using an ESAB TIG 4300I AC/DC machine and ER316L filler metal. GTAW welding efficiency (η) was taken as 60% (Khedr et al., 2023). The welding parameters as optimized based on the literature (Huysmans et al., 2021; Mohyla et al., 2020), included a current of 100 A, voltage of 12 V, travel speed of 2 mm/sec, and a shielding gas (Argon) flow rate of 12 L/min. The delta ferrite content within FZ was measured using a ferrite scope model (MF300FM, CAMBRIDGE UK). The corresponding heat input was 360 J/mm, calculated using Equation 2 (Khedr et al., 2023), as follows: Heat input (J/mm) = % !∗#∗$ !"#$ ∗&''' ( 2 ) Where η is the GTAW welding efficiency, I is the welding current (ampere), V is the voltage (volt), S GTAW is the welding speed (mm/s) of GTAW technique. 1.1.2. LW technique The printed plates were joined using LW technique using a 6-axis industrial robot equipped with a (Yb: YAG) disc laser system. Argon was used as the shielding gas with a flow rate of 30 L/min. The welding parameters, included a laser power of 3000 W, an optical diameter of 200 µm, a focal point level of -1 mm, and a welding speed of 60 mm/sec, resulting in a welding energy input of 50 J/mm, calculated according to Equation 3 (M. P. Kumar et al., 2020), as follows: E LW = (3) Where E LW is the energy density (J/mm), P LW is the laser welding power (watt) and S LW is the laser welding speed (mm/s).