Metal Additive Manufacturing Conference - MAMC 2023

Most commercial Directed Energy Deposition(DED) machine tools use pneumatic methods of feedstock handling; the current study proposes a gravity-based design. The powder metering in the current design is accomplished via a helical-grooved metering rod rotating inside a powder-filled hopper, continuously dispensing powder mass in a small user-defined quantity. This powder is then shaped into a convergent powder stream through a powder delivery nozzle, followed by its subsequent injection into the melt pool. The proposed powder handling unit exhibits several advantages over conventional ones, such as minimized spatter, improved powder recycling, minimized cost of operation, etc. Furthermore, the setup is modular and simple in nature and can be mounted to any laser welding head, thus imparting additive manufacturing capabilities. Discrete Element Method(DEM) simulations and initial prototypes establish the viability of the proposed design.