A new technology in surface finishing: Fluidized bed machining (FBM) of aluminium alloys

This paper deals with the definition of a new finishing process named fluidized bed machining (FBM). Material is removed from the workpiece by an abrasive solid emulsion and air flowing through all the equipment, scratching the surface to be finished. This process is able to produce an accurate surface finishing both on areas inaccessible to traditional methods and complex passages. The application of FBM to sheets and complex shaped components, made from two aluminum alloys, AA 2024 O and AA 2024 T3, with a widespread diffusion in several industrial sectors has been investigated. Experimental tests were performed with the aim of studying mass removal, evolution of surface topography, and process efficiency in terms of improvements in average roughness. The results of experimental tests showed that the surface profile generated and material removal were functions of the processing time, mesh size, type of abrasive, flow speed applied. The results revealed that the efficiency of the process is strongly linked to the mechanical properties of the metal treated. Furthermore, from the surface texture examination, it followed that this technique guarantees good surface finishing without influencing closest geometrical tolerances and with a rate of surface generation for ductile materials being economically acceptable.