b'Water Soluble Support MaterialINL scientists developed and demonstrated first known water for Directed Energy Depositionsoluble support material for metal additive manufacturing.Additive Manufacturing M etal additive manufacturing, specifically through directed energy deposition processes, offers an innovative alternative to traditional manufacturing. Additive manufacturing provides a method of fabricating complex geometries and highly customized three-dimensional parts that traditional manufacturing methods cannot achieve. However, metal additive manufacturing faces several key hurdles to fully realize its potential in industry. Among them, post processing issues are recognized as a significant challenge because current support PROJECT NUMBER:material technology has a direct negative effect on post processing efforts. Support 21P1064-021 structures are made of the same metal as the target part and are thus essentially TOTAL APPROVED AMOUNT:welded to the end part. Manual machining is required for support structure removal, $123,000 over 1 year increasing time, potential for part damage, and material waste in post processing while greatly decreasing design freedom. They are, however, necessary for printing complex PRINCIPAL INVESTIGATOR:geometries such as overhangs and internal features. Joshua ZelinaThis project addressed this issue by developing a water soluble support material CO-INVESTIGATORS: compatible with metal additive manufacturing. High melting temperature, water Fidelma Di Lemma, INL soluble salts were chosen for testing to fill this role. Potassium sulfate performed best Prabhat Tripathy, INLand was printed alongside Inconel 718 as a support material. The Inconel 718 part Randall Scott, INLfeatured a 90 bridge supported by the potassium sulfate. This feature would not be printable without a support material, and thus provided the simplest test case to prove potassium sulfates viability as a support material. The multi-material part printed successfully. The Inconel 718 and potassium sulfate part was then placed into deionized water that dissolved the potassium sulfate supports and left behind the Inconel 718 structure. This demonstrated the first known water soluble support material compatible with metal additive manufacturing, which represents a significant advancement in the additive manufacturing field.The development of a water soluble support material will enable the fabrication of next generation fuel designs that were un-manufacturable. Additionally, the project was the first to successfully demonstrate multi-material directed energy deposition additive manufacturing at INL, which will be instrumental in informing future research initiatives. Finally, this research demonstrated the first known directed energy deposition additive manufacturing of salts. In summary, the project achieved its goals and yielded a novel additive manufacturing capability for use in INL and industry.Additively manufactured Inconel 718 part with 90 overhang printed with potassium sulfate support structure. Shown before dissolving support structure (left) and with support structure dissolved (right).89'