A systematic study of sample preparation parameters on polishing quality, tailored to different types of coatings, is presented. Experiments employ a Ta-guchi fractional factorial approach. For ceramic coatings, polishing time and applied pressure, with secondary influence of sample positioning, and polishing wheel rotational speed affect void percentage. Micro-hardness of the coating is identified as a key factor for polishing procedure development. There is a clear common trend for ceramic coatings: coatings with higher microhardness require more severe polishing conditions (higher polishing pressure and time, increased wheel rotational speed) for proper sample preparation. For cermet coatings with moderate microhardness, void formation is mainly influenced by sample positioning on the holding wheel, while polishing pressure and time and polishing wheel rotational speed are not essential. Use of finer abrasives, ver- sus coarser ones, has proven to play a significant role in the interpretation of metallic coatings with relatively low microhardness.
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