Study of oxidation and wear behaviors of (Nb,Cr)N thin films using Raman spectroscopy

Several (Nb,Cr)N coatings were deposited by an unbalanced magnetron sputtering system. Following the deposition, the tribological properties of these coatings were studied using a ball-on-disk setup with alumina balls. The wear debris was then characterized using Raman spectroscopy to identify oxides generated during the wear process to gain a better understanding of tribochemical reactions. The results show that Cr2O3 and CrNbO4 constitute the debris obtained from Cr-rich coatings, while Nb2O5·nH2O is the major constituent of the debris formed on Nb-rich coatings. From the study of the debris, the difference in wear mechanism between Cr-rich and Nb-rich coatings is explained and confirmed.