Characterization of Inconel 718® superalloy fabricated by wire Arc Additive Manufacturing: effect on mechanical properties and machinability

Wire and Arc Additive Manufacturing has the potential to become an appropriate tech-nique to produce large complex-shaped metallic parts. However, a post-processing machining operation is necessary to reach the final geometry. In this work, Inconel 718 walls were manufactured in a monitored environment and their microstructure and mechanical properties were characterised. Then, slot milling operations were performed to investigate the influence of cutting speed and machining direction. The conclusions drawn from this article can be used as a guide for a correct definition of strategies and milling parameters. It was observed that at higher cutting speeds a better surface quality and lower torques are obtained. Moreover, the main novelty of this work is that is shows the influence of the anisotropy of WAAM-Inconel 718 on its machinability. Milling along the torch's travel direction offers better dimensional tolerance values with lower cutting torques, being more favourable than machining in the building direction. (c) 2021 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

Wire and Arc Additive Manufacturing is a promising technology for producing large metallic parts, but post-processing machining is still necessary. This study investigated the microstructure and mechanical properties of Inconel 718 walls and explored the effects of cutting speed and machining direction on slot milling operations. Higher cutting speeds result in better surface quality and lower torques, with milling along the torch's travel direction offering better dimensional tolerance values and lower cutting torques.