Fluidized bed machining of metal objects produced by additive manufacturing

Fluidized bed surface finishing of objects made by additive manufacturing technology has been investigated. Surface roughness is a crucial parameter for parts made with additive manufacturing technology, since it affects the dimensional accuracy and mechanical, tribological and corrosion resistance. Fluidized Bed Machining can be a suitable method for finishing parts with high geometrical complexity due to the high particles mobility. In this study, an experimental campaign has been carried out in a lab-scale fluidized bed apparatus with Aluminium alloy samples made by selective laser melting technology. Surface finishing has been evaluated in terms of wear and roughness under bubbling fluidization conditions while varying the sample orientation. Furthermore, the main mechanisms of particle removal are under investigation. In particular, inertial and frictional mechanisms are considered for the surface finishing process of metal parts in fluidized bed. Results show that the sample orientation affects the wear rate and the resulting roughness. Furthermore, energy dissipation models could be able to describe the finishing process of metal parts in fluidized beds.