Current Challenges Of Precision Manufacturing Through Powder Bed Fusion -Laser Beam

Paper in proceeding, 2023

Additive manufacturing (AM) technologies enable manufacturing complex designs compared to traditional manufacturing methods. There is an enormous opportunity to explore this technology which aids its evolution process to acceptable manufacturing methods. This work focuses on the dimensional
tolerances of AM parts. In particular, small features typically required in applications such as waveguides, filters, and antennas applicable for telecommunication services in the millimeter-wave frequency range are considered. In this study, the objective is to design, manufacture and test (i) a radio frequency (RF) waveguide resonator with small features and (ii) a test artefact featuring a variety of small features ranging from canonical shapes to complex shapes exploited in the RF resonator. Precision parts are manufactured using powder bed fusion-laser beam/metal (PBF-LB/M), and geometrical deviations of their small features are measured and compared between parts printed at different positions on the build plate. The geometrical deviations of the fine features are characterized using a scanning electron microscope (SEM). Also, resonance frequencies and Q-values of the RF resonators are measured. It is found that the manufactured parts have a surface roughness subject to orientation and strategies with powder particles fused to the small features. Geometrical accuracy in the range of tens of micrometers and RF resonance frequency with a small spread between samples but systematic deviation from the nominal value were measured.