Wire + Arc Additive Manufacturing (WAAM) is a type of directed energy deposition additive manufacturing technology that uses an electric or plasma arc to melt a wire feedstock. The layer-wise nature of the process can lead to an accumulation of heat as additional layers are repeatedly applied and the build height increases. In addition to the heat accumulation and slowed cooling rate, repeated applications subject the previously deposited layers to a thermal cycling effect that can negatively affect the microstructure, mechanical properties and the bead geometry of WAAM-fabricated parts. As a result, properties of WAAM parts cannot meet those of their wrought equivalents in the same alloy.
This presentation presents an overview of the various different strategies employed to enhance the mechanical properties of WAAM-fabricated parts. Through a comprehensive overview of the literature, some strategies were found to be effective at enhancing mechanical properties, and some were shown to make little to no difference. The various merits of the effective strategies are discussed, not only as they relate to properties, but also to the commercial applicability of the techniques. With this knowledge, a roadmap for the future of WAAM development is presented to further the adoption of WAAM for commercial applications.
- Understand the challenges of WAAM technology, both processing and materials properties
- Discern between the various improvement strategies for WAAM
- Upon completion, participants will be able to identify the best strategies for improving properties of WAAM parts