Abrasive Fluidized Bed (AFB) finishing of thermally sprayed cobalt-chromium coatings

Abrasive Fluidized Bed (AFB) finishing of cobalt-chromium coatings is investigated. Cylindrical metal components coated by High Velocity Oxygen Fuel (HVOF) with Stellite 6 were machined, while rotating at high speed in a bed of suspended Al2O3 abrasives. The interaction between abrasives and coatings was analyzed varying the machining time, abrasive size and rotational speed. The morphology and dimensional stability of the machined parts was monitored by microscopy, profilometry and dimensional analysis. AFB is able to smoothen the morphology of the Stellite 6 coatings, preserving their dimensional accuracy. This makes AFB a promising technique in the reprocessing of hard coatings.