Study on the Microstructure and Friction Characteristics of ZrN Coatings Containing Cu and Si

To improve the mechanical properties of coatings used in cutting tools and automotive parts, ZrCuSiN coatings were deposited in an argon-nitrogen gas mixture using magnetron sputtering at various nitrogen gas flow rates. The structural properties of the fabricated ZrCuSiN coatings were investigated using the friction coefficient, wear coefficient, coating hardness, and elastic modulus via nano indentation and ball-on-disk friction testing. The surface morphology of the coatings was analyzed using scanning electron microscopy (SEM). The structural characterization results show a typical face-centered cubic ZrN structure with peaks in the (111) and (200) directions. The highest hardness was obtained for coatings deposited at a nitrogen gas flow rate of 5 sccm, and the coefficient of friction was lowest at a nitrogen gas flow rate of 3 sccm. It was found that the high hardness of the coating causes wearing of the counterpart. In contrast, a 3 sccm coating with stable hardness and coefficient of friction was found to be the most optimal.