Experimental investigation of coatings efficiency in micro-ball-end milling of pre-sintered 5Y-TZP ceramic

Abstract This study deals with micro-ball-end milling of a pre-sintered Yttria Tetragonal Zirconia Polycrystal. The aim is to underline the reliability of different coatings while machining this material regularly used in dental and luxury industries. A particular tool configuration – which is identified as critical by the targeted sectors – is tested previously determined stable cutting conditions, for all the chosen coatings. Cutting forces, tool reliability and surface integrity data is obtained by green machining of a 5Y-TZP (tetragonal zirconia polycrystal stabilized by 5%mol of yttrium) with 1 mm diameter tungsten carbide micro-tools coated with two PVD and one CVD coatings (respectively AlCrN, DLC and diamond). The results highlight that the choice of an appropriate coating is mandatory for this type of abrasive ceramics, even if they are partially sintered. Material flow, tool wear and machined surface quality are discussed and correlated.