**2. Experimental setup**

For WAAM®, two welding equipment were used: a three-axis gantry machine with programmable logic controller (PLC) and a two-axis welding portal FCB 900–500/ML100 (**Figure 1**). To achieve a low heat input (E), the welds were made using the Cold Metal Transfer (CMT) process of the company Fronius. For logistical reasons, two power sources (PS) were used with the RCU 5000 control unit: CMT TPS 4000, first generation (PS 1) and CMT Advanced 4000, second generation (PS 2). However, the welds were made with the same synergy line (NIBAS 625/1.2mmM12 Ar + 2,5% CO2). Accompanying the welds, the electrical welding parameters, the shielding gas flow, and the wire feed speed were recorded and monitored with external measuring system WeldAnalyst-S2 (HKS Prozesstechnik GmbH). During the welding process, infrared pyrometers were used to measure the temperature of the welded parts. Two batches of solid wire S Ni 7718 from different manufacturers with diameter 1.2 mm were used. One of them is a standard batch, while the other is made specifically for AM.
