Metal Laser Powder Bed Fusion (PBF-LB/M Powder Bed Fusion, Laser-Based/Metal) offers decisive advantages over conventional manufacturing processes. Complex geometries can be produced that cannot, or only to a limited extent, be manufactured with conventional manufacturing processes. One of the main disadvantages of the process are high investment and operating costs. In order to make the PBF-LB/M process accessible to new research areas, the costs need to be reduced. Therefore, this work investigates whether laser beam sources and motion systems in currently established PBF-LB/M systems can be replaced by more cost-effective components. To reduce the operating costs for PBF-LB/M, the studies are carried out based on previous work with water-atomized, process-foreign sinter powder instead of gas-atomized, spherical PBF-LB/M powders. A cost-efficient, low-alloyed powder is selected (Höganäs HP1) and processed on two different PBF-LB/M machines with a restricted process window using process parameter values that current low-cost machines can achieve. The results show that a multimode fiber laser leads to a more stable process and wider melt pools compared to a single mode fiber laser. In addition, a lower sensitivity of the process with respect to modified process parameters is observed for the multimode laser, resulting in a wider range of stable process windows. A Cartesian motion system (gantry) is suitable for use in PBF-LB/M despite lower scan speeds compared to galvanometer scanners. Beam guidance in the XY-plane offers new possibilities for machine and process design that are not possible with usual scanner systems.
Soft-magnetic materials can benefit significantly from additive manufacturing using Laser Powder Bed Fusion of metals with laser beam, as this technology allows the production of parts with complex geometries. In this study, two iron-based alloys were investigated: Fe-10%Ni (at%) and Fe-10%Si (at%), which are known for their promising soft-magnetic properties. A parameter study was first conducted to optimize the process settings with the goal of maximizing the relative density, which strongly influences magnetic performance. Using AI-based optimization software (xT-Saam by Exponential Technologies Ltd., Riga, Latvia), geometrically simple specimens with a relative density of ≥99.95% were successfully produced. Utilizing the developed parameter sets, toroids were manufactured and heat-treated to improve their magnetic properties. The best obtained ferromagnetic properties were HC = 1621 A/m (coercivity) and µR = 305 (permeability) for Fe-10%Ni, and HC = 300 A/m and µR = 1114 for Fe-10%Si.