Tribological characterization of carbon-nitrogen coatings deposited by using vacuum are discharge

Carbon nitride (CN) films have been deposited by using the pulsed vacuum are method on silicon and metallic substrates. Films were deposited in a nitrogen gas ambient varying between 0.01 and 0.56 Pa. The nitrogen content of the films as analysed by using ion-beam methods (NRA) varied from 0 to 34 at.%. The microstructure was characterized by using Raman spectroscopy. The wear and friction properties of the CN films as a function of nitrogen content were measured by using a pin-on-disk apparatus. The CN films had consistently higher coefficient of friction as the nitrogen content was increased, especially at lower values of relative humidity. Against the steel pin, wear rates of the CN films varied from 0.1 to 0.5 x 10(-16) m(3) N-1 m(-1) as the nitrogen content grew from 0 to 34 at.%, respectively. The compressive stress of the films with high nitrogen concentration was significantly lower than for pure DLC, which allows the growth of film material with an excellent wear resistance and a higher film thickness.