Influence of Powder Particle Size Distributions on Surface Topography of Polymer Laser Powder Bed Fusion Parts

The morphology and particle size distribution of commercial polymer powders for Laser based Powder Bed Fusion (PBF-LB) spans a wide range. This is a consequence of the traditional manufacturing methods of milling and grinding. In theory, a combination of large and fine powder particles provides dense powder packing which in turn allows for good processability and parts. This study focuses on correlating powder properties and part quality for parts manufactured with 3 different size distributions, i.e. commercial grade, narrower than commercial, and a mix of different size spans. Parts were made with polyamide-11 and the results indicate a more suitable particle size distribution for a specific material and a specific machine. Hence spending some additional resources on sieving powder prior to use can be beneficial. However, an optimization should be carried out for each powder and material to find the ideal powder size distribution corresponding to desired part quality.