The need to fabricate and repair large-scale structures in forward deployment capacities is of extreme importance for future space and terrestrial missions. As such, welding-derived metal AM technologies such as wire+arc additive manufacturing (WAAM) have been created to meet this need. The benefits of WAAM compared to the more common laser powder bed fusion techniques are numerous including the ability to manufacture and assemble components greater than 300 mm in height under microgravity conditions, mechanical properties comparable to wrought materials in the as-built condition, and >200% higher build rates. However, the process-structure-property relationships for wire-feed AM materials and structures are not well-known which currently precludes significant advances in employing this technology as a viable tool for manufacturing and repair of mission critical structures.

We seek to characterize location and orientation dependent properties within large, WAAM structures in an effort to certify their use in engineering applications. Primarily, the effect of process variables on cyclic fatigue and fracture properties are investigated and connected to microstructure and residual stress distributions resultant from high-energy processing. Future work in this area includes process development for advanced WAAM alloys, optimization of robotic control, and scalability.