Additive Manufacturing of Functional Inconel 718 Parts from Recycled Materials

This paper focuses on manufacturing and characterization of geometrically complex functional parts fabricated from recycled Inconel 718, a nickel-based superalloy. A novel gas atomization process was used to produce the feedstock for a powder bed fusion process by recycling and melting used Inconel parts. An analysis of the melt-pool geometry and microstructure was conducted using finite element method to determine the optimal print parameters for an EOS M100 3D printer. Densities and mechanical properties of recycled Inconel 718 were tested for various printing parameters using standard test methods and anisotropic tensile behavior of additively manufactured parts were studied. The experimental data were compared with historical and simulated data and indicated equal or better properties compared to the baseline. Chemical composition, microstructure, and fracture surface of broken samples were also examined. Finally, a simulation of the additive manufacturing process was performed using the mechanical properties results and was used to redesign and build a turbine for an automotive turbocharger. The results of this study indicate that scrap Inconel 718 parts can be used to additively manufacture high-quality functional parts.