A Method and System to Produce Linear Metal Feedstock from Heterogeneous Metal Particles

Wire-fed and extrusion-based additive manufacturing (AM) processes depend on linear feedstocks such as wire, rod, billet, and strip. Reclaimed materials, including out-of-specification AM powders and machining chips, present an opportunity to reduce material waste, production costs, and dependence on pristine feedstocks. However, feedstock internal structure can affect deposition bonding and the mechanical performance of AM components, and converting reclaimed materials into linear feedstocks can homogenize particles. Therefore, there is a need for an efficient processing method that converts heterogeneous metallic particles into linear feedstock while enabling controlled mechanical property gradients to improve the performance and reliability of additively manufactured components.

 

Researchers at Arizona State University have developed a novel method to convert heterogeneous metal particles, including reclaimed machining chips, into linear feedstock forms for wire-fed and extrusion-based additive manufacturing (AM) without remelting. This approach utilizes a combination of processes to consolidate particles while retaining selected spatial differences in composition. The feedstock may be configured with continuous composition gradients or sharper transitions between materials, providing a potential feedstock-level route to site-specific properties in manufactured components. In an initial demonstration, a mixed aluminum machining-chip feedstock was consolidated into strip form. Microstructural analysis reported oxide disruption, inter-chip bonding, and a fine equiaxed grain structure, while also identifying residual voids and incomplete bonding between layers in portions of the demonstrated strip.