Investigation of tribological properties and mechanical performance of tungsten carbide cutting tool material coated with AlTiCN and CrCN thin films

In this thesis, the tribological properties of AlTiCN and CrCN coated Tungsten Carbide (WC) cutting tools and their machining performance in both CNC vertical machining center and CNC lathe were investigated. Coatings; were applied on end milling tools, lathe inserts and 12x12x5 mm sized test samples made of Tungsten Carbide material by Cathodic Arc Physical Vapor Deposition (CAPVD) method. The structural, mechanical and tribological properties of the applied coatings were determined by X-Ray Diffractometer (XRD), Microhardness Device, Tribometer Device and Scanning Electron Microscope (SEM) on the test specimens. In addition, in order to determine the cutting and wear performance of coated and uncoated tools, 1.2738 plastic injection mold steel (IMPAX) work piece was processed at high speed dry machining in a CNC vertical machining center and using coolant on a CNC lathe. CAM codes of the processed geometries were created by the SolidCAM program. The iMachining operation was preferred for the milling process and the cutting speed, feed rate and overlapping values in the program were determined automatically and variably according to the geometry, tool and work piece material. After machining, the wear behavior of the tools was investigated by SEM and mass loss method. After the cutting process, the surface roughness values of the work piece were determined by optic profilometer device. According to the results obtained in these tests; it was determined that AlTiCN has higher adhesion value compared to CrCN and the abrasion rate was also lower. It was determined that the tools with AlTiCN coating after machining processes have superior properties in terms of both mass loss and flank wear.