Journal of Laser Applications (October 2024)
by Francesco Bruzzo (Fraunhofer, Institut für Werkstoff und Strahltechnik); Matteo Alberghini, Andrea Bertinetti, Alessio Tommasi (Gemmate Technologies); Mirko Riede (Fraunhofer, Institut für Werkstoff und Strahltechnik); Daniele Pullini (Centro Ricerche Fiat) and Elena López (Fraunhofer, Institut für Werkstoff und Strahltechnik)
Abstract
Amongst metal additive manufacturing technologies, Direct Energy Deposition (DED) processes have the advantage to be easily integrable in a manufacturing chain with other conventional technologies. This characteristic can be exploited by designing reinforcement structures to be added by DED onto pre-existing subcomponents to tailor the part´s mechanical properties while keeping the part light-weight. This study focuses on DED by means of laser beam and powder (DED-LB/P) process optimiza-tion to improve material quality and geometrical accuracy of AlSi10Mg reinforcement structures while preventing excessive thermal deformations and material dilution into the substrate. These results are compared with finite elements numerical simulations of the deposition process, comprising thermo-elastic deformation and material deposition, to predict the bending and reinforcement of the pro-cessed substrate. In particular, the model includes the deterministic prediction of the deposition pro-file as a function of the process parameters and a few condition-specific coefficients: once calibrated, the model was used to compare the numerical and experimental residual deformation of the rein-forced sample, obtaining promising agreement. The reinforcement provided to a 1.5 mm thick sub-strate by a single wall of deposited material, with cross sectional dimensions of 2 mm in width and 2.5 mm in height, was evaluated by 3 points bending. With the reinforcement on the tensile side of the stresses, the energy absorbed by the material plastic deformation increased by 2.4% as compared to the substrate alone, while with the reinforcement on the compression side of the stresses the energy absorption increased by 75.8% on average.
