PROPERTIES AND TRIBOLOGICAL BEHAVIOR OF TI(C,N) COATINGS DEPOSITED BY REACTIVE ION PLATING

Ti(C,N) films have been deposited by reactive ion plating and their tribological behavior against steel in air and in argon atmosphere was characterized. It was very effective to decrease wear rate of steel to coat Ti(C,N). The influence of atmosphere on wear of the Ti(C,N) coatings was studied in the dry sliding of steel pin using a pin-on-disk configuration. The wear rate in air was lower than that in argon atmosphere. The decrease of the sliding wear of the steel disk by applying the Ti(C,N) coating was due to formation and growth of iron-oxide particles on the surface of the coating and high shear strength of the coating. A lot of fine and thin iron-oxides were observed at the sliding surface of the Ti(C,N) coating in air and they were identified as magnetite (Fe3O4). It is suggested that small iron debris is derived from pin and oxidized by the reaction with oxygen in air and a protective oxide particle can be formed by growth of oxide debris. These oxides are considered to insulate steel substrate from steel pin, resulting in decreasing adhesive force between pin and disk. Wear behavior of the Ti(C,N) coatings by changing atmosphere is discussed in comparison with a case of steel pair.