Implementation of a nozzle-based powder deposition mechanism for multi-material powder bed fusion using a laser beam

This study presents the implementation of a novel nozzle-based powder deposition mechanism designed for three-material powder bed fusion using a laser beam. The research outlines the hardware configuration, featuring a six-axis articulated robot to maneuver the powder deposition system within the PBF-LB machine. The deposition system and powders were optimized to achieve three primary objectives: precise powder dosing, selective powder deposition, and homogenization of the powder layer. These investigations are essential and foundational for enabling applications that require three-material processing, such as the targeted production of battery cell caps. Battery cell caps require pure aluminum, pure copper, and an electrically insulating material (in this case a ceramic mixture). The aluminum powder is applied using the machine’s conventional recoater system. To facilitate the deposition of the second and third materials, the additional nozzle-based deposition mechanism must be integrated into the machine. Consequently, this study focuses on the deposition behavior of copper and ceramic powders using the nozzle mechanism. Through analysis of powder rheology, morphology, and granulometry, experimental insights were gained to understand, design, and optimize the deposition mechanism. The findings were used to examine flow-optimized powder composition and powder throughput. Following this, single and multiple powder tracks were deposited in the build chamber to evaluate the deposited track widths. Finally, the derived insights and scientific understanding were synthesized into guidelines, to provide a framework for applying the methodology to other powder materials for future applications.