Mechanical and tribological properties of ion-beam-enhanced-deposition TiN thin films

Abstract

Hard titanium nitride thin films were deposited using the ion-beam-enhanced deposition (IBED) technique. The deposition process involves sputtering the titanium target whilst using an N+ ion beam to bombard the film. The deposition parameters were changed by varying the ion bombardment energies and bombardment procedures. The microstructure and microhardness of the thin films were studied. The tribological behavior of the films was evaluated using the block-on-ring sliding wear test. The bonding strengths of the films were evaluated by a new method modified from the rolling-contact fatigue test. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis showed that the grain size increased with increasing bombardment energy. X-ray diffraction (XRD) results indicated that when the bombardment energy increased from 10 to 40 keV, the preferred orientation was changed from (111) to (200). The results showed that both the hardness and the wear resistance of the film decreased with an increase in bombardment energy. The effect of ion bombardment procedures on the bonding strength of the thin films is discussed.