Tribological characteristics of titanium nitride and titanium carbonitride multilayer films. Part II. The effect of coating sequence on tribological properties

The effect on the tribological behavior of the lower specimen (disc) with different total film thickness and different coating sequences of two ceramic films was examined. The tribological behavior in response to the above two factors are expressed in terms of the wear rate of the upper and lower specimen, friction coefficient, wear mechanism, wear debris size and wear displacement. The lower specimen wear rates can be regressed by two straight lines or two curves as a function of the friction power parameter. Friction coefficients can be expressed as two linear functions in terms of the parameter T/LV where T is the specimen's ultimate temperature, L is the applied load and V denotes the sliding velocity. The characteristics exhibited in the wear rate of the lower specimen and friction coefficient in each subregion of the friction power parameter (fLV) and the parameter T/LV, respectively can be interpreted by the alterations in wear mechanism. The wear rate of the lower specimen where the Ti(C,N) film is the top layer is equal to or lower than that with the TiN film as the top layer if they are both evaluated at the same thickness and under the same operating conditions.