Ion Bombardment Effect on the Hardness of Ti(C,N,O) Films Prepared by Ion Beam Controlled Deposition (IBCD)

Ion beam controlled deposition (IBCD) or ion beam assisted deposition (IB AD) of Ti(C,N,O) films has been investigated much in the last decade for both the advantage of this advanced technology and the promising properties of such materials. Ti(C,N,O) films are various solid solutions of interstitial compounds TiC, TiN and TiO of F.C.C structure with lattice constants lying between the values of the pure compounds. Some content of oxygen improves their wear resistance due to the lower fn;e enthalpies of such films in comparison with pure TiC and TiN films [1]. Many so-synthesizcd titanium carbide and titanium nitride films reported in published papers were actually of this sort as they often had more or less oxygen content from residual gas in vacuum. A number of papers were contributed to depict the texture and composition dependence of film on the arrival ratio of assisting ions versus deposited atoms (AR) as well as their mechanical properties [2–6]. However, the film formation mechanism in IBCD isn't quite clear yet, especially for cases with assisting ion energy of several to tens of keV. During a course to synthesize Ti(C,N,O) films by IBCD with the two beam technique, datum were accumulated. Based on a part of it, a previous paper on ion beam governed preferential growth in IBCD has been published [7]. This paper was aimed to search for the origin of ion bombardment effect on film hardness.