Deposition and characterization of Ti(C,N,O) coatings by unbalanced magnetron sputtering

Several TiCNO coatings were deposited using an unbalanced magnetron sputtering system. The coating properties as a function of oxygen/nitrogen flow ratio were studied using glow discharge optical spectrometer, X-ray diffraction, scratch testing and nano-indentation measurement. The tribological properties of the coatings were then investigated using a ball-on-disk setup with alumina balls. The results show that coating properties and performance are greatly affected by the flow rate of oxygen. With oxygen flow rate at 4 sccm during deposition, the TiCNO coating shows the lowest wear rate among all. Further increase in oxygen flow rate caused a decrease of hardness, adhesion and wear resistance, while together with the increase of friction coefficient. Also found is that the color of these coatings changes as a function of oxygen flow rate, indicating that these coatings can be used as decorating thin films with wide variety of choices.