The main equipment in the laboratory is a metal additive manufacturing machine using plasma and fed by wires. The manufacturing technology is called PAW-WAAM, which stands for Plasma Arc Welding-Wire Arc Additive Manufacturing, meaning additive manufacturing by induced plasma arc. The plasma is continuously fed by pure argon gas (99.99%). The bed upon which work is performed can support metal prints weighing up to 300 kg. It’s worth noting that this equipment is of Spanish origin, specifically from Durango (Basque Country).

The equipment uses the PA-WAAM technique, where a constricted arc is generated between a non-consumable tungsten electrode (negative polarity) and the base metal. The W electrode is encased in a special copper (Cu) nozzle (inner chamber) inside the torch, which confines the arc. An inert gas, mainly argon (Ar), is supplied through the Cu inner chamber which is then energized to form a plasma. Shielding gas, also inert, flows out from an outer ring of the special Cu nozzle. Therefore, compared to the more popular GTA-based technique, PAW-WAAM offers higher energy density, enhancing arc stability and reducing contamination.
Our PAW-WAAM equipment is a P1200- 4X-I model supplied by ADDILAN (Addilan Fabricaci ́on Aditiva S.L., Du- rango, Spain). This equipment comprises a CNC machine with cartesian axes (gantry). The heat source is a Tetrix 552 AC/DC Synergic Plasma AW GR (SCO 4103) generator and a T drive 4 Rob 3 RE HW, from EWM. Additionally, the machine features a PMW 350-2 torch allowing material deposition with a current of up to 350 A. Throughout the WAAM processing, the voltage is monitored online, to ensure that layers were deposited at a constant torch height (through-the-arc sensor principle).