Ultrasonic Atomization Of Recycled Aluminum Feedstock: From Single Alloy Scrap To Cross-Scrap Alloy For Plasma- And Powder-based Directed Energy Deposition

Authors: Daniel Vieweger (Technische Universität München, Germany) Josip Vincic (Technische Universität München, Germany) Peter Mayr (Technische Universität München, Germany) Abstract: This work investigates ultrasonic atomization (UA) as a versatile route for transforming aluminum scrap into powder feedstocks suitable for plasma- and powder-based Directed Energy Deposition (DED-Arc-P) within a circular manufacturing framework. Both single-alloy scrap and mixed post-consumer scrap from different alloy families were converted into powders to explore recycling pathways of different complexity. UA was employed to melt and homogenize the scrap material, producing spherical powders. The powders were analyzed with a focus on their chemical composition and general powder quality. They were subsequently processed using DED-Arc-P to assess overall processability, defect tendencies, and microstructure, with a focus on phase formation resulting from the mixed-alloy approach. Using mixed scrap streams instead of narrowly specified alloys reduces reliance on primary metal with tight compositional tolerances and enables higher overall scrap utilization. The results highlight a promising method for producing resource-efficient aluminum feedstock and promoting more sustainable additive manufacturing. DOI: https://doi.org/10.59499/EP267143775