The wear performance of carbide tools coated with TiAlSiN, AlCrN and TiAlN ceramic films in high seed milling process

Keywords: Cathodic arc physical vapor deposition, TiAlSiN, AlCrN, TiAlN, Wear, High speed milling, Intelligent machining, SolidCAM iMachining. Nitride-based coatings are applied by cathodic arc physical vapour deposition (CAPVD) to improve the tribological properties of cutting tools. The present study examines the tool life of carbide tools coated with TiAlSiN, AlCrN and TiAlN films in intelligent machining process. Coating process was applied on both prismatic carbide test specimens and solid carbide end mills by CAPVD method. Coating characterization was carried out on the test specimens. The structural and mechanical properties of different nitride-based coatings were investigated by means of field emission scanning electron microscope, X-ray diffractometer, scratch tester, calotester, microhardness device and optical profilometer. The tribological properties of specimens were examined in dry conditions by using reciprocating sliding wear test with Al2O3 ball as a counter material. Impax steel was machined in CNC vertical machining centre with uncoated and coated carbide end mills in order to determine the actual operating performance of the coatings. The G codes and tool paths were created in the SolidCAM iMachining software. The cutting speed, feeds and overlap values were selected automatically and variably depending on geometry, tool and work piece materials. After the machining process, the wear performance of tools were examined by SEM and the mass losses on the tools were determined by the precision scale. In addition, the surface roughness values of the impax steel were measured from the finish surfaces. According to the scratch test results, the best adhesion results were obtained for TiAlN coating and the Lc1 critical load value was determined as about 30 N. The reciprocating sliding test results showed that the highest wear rate was obtained for the TiAlSiN coated specimen and the lowest wear rate was obtained for the untreated specimen. Flank wear was observed on the tools after the milling process and the highest wear resistance was obtained TiAlN coated end mill.