Comprehensive tribological characterization of thin titanium nitride-based coatings

Innumerable papers have been published so far describing tribological investigations of thin hard coatings based on titanium nitride. Analysis of the presented results demonstrates a large dispersion of measured friction and wear numbers, whereas titanium nitride-coated pieces and tools have proved their benefits in a broad area of applications. Therefore an attempt was made to clarify the influences on friction and wear test results by varying the coating process, the tribological stresses due to sliding, fretting and rolling motion and by changing the surrounding medium. The results reveal that machining of substrate surfaces and type of tribological stresses due to sliding, fretting and rolling have an important influence. The formation of reaction layers is dominating the tribological behavior in most cases.