Electrophotographic Powder Application for Metal Powder bed based Additive Manufacturing

The scope of this paper is the systematic investigation and conceptual design of a process based on the principle of electrophotography for the application of particles on a build plate with the focus on powder bed based fusion of metals by means of a laser beam (PBF-LB/M). The influence parameters for the particle transfer from the photoconductor to the build plate are investigated using a prototype based on the stamp principle. In this setup the process is extended for the first time by the sequence of powder deposition compared to [1, 2]. The investigations of this work concentrate exclusively on a full-area attraction on the photoconductoŕs surface and its deposition. The attraction of the powder to be deposited is performed without an exposure sequence. Significant parameters for the system are identified and measures to ensure a reproducible deposition are derived. Within the scope of experimental investigations, the PBF-LB/M typical powder 1.7147 (20MnCr5) with a particle size distribution of 15 to 56 μm is tested with regard to the deposition quality (surface coverage density and layer thickness) in a single- and multi-layer deposition. The stacking of the particle layers not only increases the area coverage density, but also demonstrates the basic transferability for generating a powder bed, which is required for additive manufacturing.