Fast Regime-Fluidized Bed Machining (FR-FBM) of Atmospheric Plasma Spraying (APS) TiO2 coatings

This paper deals with the development and application of a new technique, Fast Regime-Fluidized Bed Machining (FR-FBM), for the easy-to-automate finishing of as-deposited Atmospheric Plasma Spraying (APS) TiO2 coatings on AISI 1040 steel substrates. The effects of leading FBM operational parameters, namely, abrasive size, jet pressure and processing time, were evaluated by using a full factorial Design Of Experiments. Machinability of APS APS-TiO2 coatings was found to be highly dependent on jet pressure and on abrasive mesh size as they affect the contact conditions between the abrasive and machined surface as well as the finishing force. By modifying these conditions, FR-FBM allows 3 to 4-fold improvements in roughness parameters of as-deposited APS APS-TiO2 coatings and imparts minimal defects or alterations to the machined surface, whilst maintaining its ability to guarantee the respect of the closest geometrical tolerances.