Investigating the Reproducibility of the Wire Arc Additive Manufacturing Process

Abstract

Wire arc additive manufacturing (WAAM) of titanium parts shows promising potential for aerospace application due to its high deposition rates allowing a fast and economical production of large integral parts. However, due to the demands of aerospace industry an extensive qualification procedure is necessary to enable the parts as ready to fly. Nowadays, qualification for additive manufactured parts is a time-consuming process, so the advantages in additive manufacturing cannot be fully utilized. For this reason, a complete process qualification for WAAM would reduce the costs drastically in contrast to qualifying manufactured parts individually. As a first step the robustness and reproducibility of the energy reduced WAAM process was investigated. Thick-walled samples are manufactured layer by layer with an oscillating welding head motion. The mechanical properties of the samples are compared on an adequate statistical basis. Microstructural-and computer tomography analysis are conducted to comprehend shown interactions. The reproducibility is investigated in dependence of different heat treatment states, different directions of mechanical testing and two manufacturing systems of the same type.

Influence of oxygen content in the shielding gas chamber on mechanical properties and macroscopic structure of Ti-6Al-4V during wire arc additive manufacturing

“…The samples were cut into two sections and one section of each sample was heat treated for 2.5 h at 650 °C in an oven constantly purged with 10 l/min of Argon 4.8 gas. This temperature regime is commonly chosen within aerospace industry to relieve the thermal stress of Ti-6Al-4V and its influence on the tensile properties has been previously investigated [16]. The heat-treated section was used for hardness and tensile testing.…”