Fluidized bed finishing of additively manufactured objects: The influence of operating parameters

This study investigates the potential of Fluidized Bed Finishing (FBF) of square flat AlSi10Mg specimens manufactured via Laser-Powder Bed Fusion (L-PBF) additive manufacturing technology. Two FBF operational modes were experimentally investigated: I) with stationary specimens; II) with specimens under controlled rotational motion. Four different abrasive materials have been tested, quartz sand, corundum, irregular steel and cut wire steel particles, characterized by different hardness, density and shape. The effect of the abrasive material, processing time and specimen tilt angle was investigated. Results showed moderate smoothing under stationary specimen configuration, while good finishing for rotation-assisted tests, maximum reduction of the surface roughness of 12% and 67%, respectively. Steel particles were the most effective bed material, with particle density overtaking hardness as key particle property. The optimal tilt angle was the one that maximized sliding and shear. Altogether, surface finishing is driven by surface shear forces dominated by inertial stresses in particulate phase.