Effect of Particle Size Distribution of Meta! Powder on Powder Bed and Building Characteristic in Metal-Based Powder Bed Fusion with Laser Beam

This study fbcuses on the particle size distribution of the metal powder used in powder bed fusion with a laser beam (PBF-LB/M). The metal powders used in the PBF-LB/M are classified after granulation and contain a mixture of small and large powder. The influences ofdifferent particle size distributions on the powder properties such as thermal conductivity and laser absorption, powder bed properties, and building characteristics were investigated. In addition, the melting phenomenon of the powder during single-track building in the PBF-LB/M process was visualized with a high-speed camera to investigate the influences of different panicles size distributions on the behavior of spatter particles. Furthermore, surface building was conducted on a commercial building machine, and the properties of the obtained objects were evaluated. The results showed that the thermal conductivity increased, and the laser absorption decreased when ihe mean particle size of the metal powder increased. It was revealed that as the mean particle diameter increases, the number ofspatter particles decreases, the scattering velocity decreases, and the spatter size increases. Furthermore, the number of spatter particles adhered to the surface of the obtained built structure decreased as the mean particle diameter increased. © 2024 Japan Society for Precision Engineering. All rights reserved.