Effect of substrate preheating and in situ cooling on dimensional accuracy, microstructure, and hardness of wire-arc directed energy deposition components

Arc-based directed energy deposition (DED-Arc) is a promising manufacturing technology on the rise in the industry. Onthe one hand, convincing process advantages, such as the possibility of sustainably producing complex and large-volumecomponent geometries with comparatively high building rates, favor further industrial interest. On the other hand, thereare still challenges, like the difficulty of controlling heat input and the intricate thermal history. The resulting temperaturegradients and heat accumulations lead to inhomogeneous component properties and reduced process efficiency, which delaysfurther establishment in the manufacturing industry. Therefore, implementing and developing concepts for thermal manage-ment in DED-Arc is necessary. The study examines how controlling the substrate temperature can affect the dimensionalaccuracy, microstructure, and hardness of DED-Arc components. Different preheating and in situ cooling strategies weredeveloped based on numerical investigations, including a water-cooled in situ cooling unit, a cobot-guided inductor, andclassical preheating approaches. The findings indicate that substrate tempering significantly impacts the penetration zoneand heat-affected zone dimensions, layer widths, microstructure, and hardness profiles. A special combination of preheatingand in situ cooling resulted in enhanced substrate bonding, uniform layer widths (4.0 ± 0.1) mm, and consistent hardnessvalues (142 ± 10) HV due to a more uniform microstructure. These results indicate that integrated substrate plate temperingcan significantly improve thermal process control in DED-Arc, supporting its further industrial establishment.     «

Arc-based directed energy deposition (DED-Arc) is a promising manufacturing technology on the rise in the industry. Onthe one hand, convincing process advantages, such as the possibility of sustainably producing complex and large-volumecomponent geometries with comparatively high building rates, favor further industrial interest. On the other hand, thereare still challenges, like the difficulty of controlling heat input and the intricate thermal history. The resulting temperaturegradients and he...     »