The deposition of low-friction TiN–MoSx hard coatings by a combined arc evaporation and magnetron sputter process

TiN–MoSx coatings have been produced using a hybrid reactive arc (TiN) and magnetron sputter (MoSx) deposition process. The process allowed a maximum total Mo and S incorporation of 8 at.%. The coatings displayed a cubic TiN structure with slightly enlarged lattice constants. By suitable process parameter control, coatings of high adhesion on hardmetal and HSS substrates were produced. Hardness values of up to 30 GPa and friction coefficients against steel and Al2O3 of less than 0.2 were obtained for the TiN + 8 mol% MoSx coatings. To determine the suitability of such coatings for use in dry machining, the lifetime of coated drills used in lubrication-free conditions was measured. A comparison of the best performing drills showed the TiN + 8 mol% MoSx coating to increase the lifetime by almost twofold with respect to the TiN coating and up to fivefold with respect to an uncoated drill.