Effect of adhesive and cohesive strength on the tribological behaviour of non‐reactively sputtered TiC thin films

Abstract

Titanium carbide (TiC) thin films were deposited on D9 steel substrates at room temperature (RT), 200• C and 400 • C. A compound TiC target was sputtered to deposit films in a non-reactive argon atmosphere. As-deposited films were characterised for structural, chemical and mechanical properties. Nanoindentation and scratch tests were performed to evaluate the cohesive and adhesive strength of the films, respectively. Tribological properties of the films were investigated using a tribometer. An increase in nano-hardness from 7.2 to 10.5 GPa was observed as deposition temperature was increased. The films deposited at RT and 200• C showed poor adhesion leading to the inferior tribological performance. In contrast, films deposited at 400 • C showed better adhesion which improved the wear resistance. Tribological behaviour of TiC thin films was correlated with contact deformation modes of coatings. These modes revealed significant role of adhesive and cohesive strength associated with the coatings.

Effect of Annealing Temperature on Microstructure and Resistivity of TiC Thin Films

“…Figure 2g-i shows the SEM cross-sectional images of TiC films with different sputtering time, annealed at 800 • C. From the images it can be seen that thickness of TiC films increased linearly with the accumulations of sputtering time, and based on this, the estimated growth rate of film was about 30.8 nm/min. Continuous columnar crystals [34,35] can be observed for thin films with a thickness of 251 nm, but it was less obvious with the increase in thin film thickness.…”

“…For the as-deposited film, two doublet peaks Ti 2p 1/2 and Ti 2p 3/2 can be observed. The Ti 2p 3/2 peak exhibited two components of binding energies at 454.12 and 458.71 eV which correspond to the metallic Ti-Ti binding [17] and TiO 2 phase [19], while the Ti 2p 1/2 peak included two components of binding energies centered at 460.79 and 464.36 eV, which are related to TiC [34] and TiO 2 [41,42] phases, respectively. With the increase in annealing temperature, the Ti-Ti correlation peak shifted to the high binding energy side, reaching 454.78 eV (close to TiC), which may be due to the further increase in oxidation degree [34], while the intensity of the TiC correlation peak decreased [43], which may be due to the increase in carbon content (dissociation from TiC).…”

Carbon nanofiber toughened nc-TiC/a-C nanocomposite coatings

“…To remove the surface contamination layer, Ar ion bombardment was carried out using a differential pumping ion gun (Kratos MacroBeam) with an accelerating voltage of 4 keV. The bombardment was performed at an angle of incidence of 45° with respect to the surface normal.Because of preferential sputtering, the etch duration can not be too long and in literature it is a few minutes to fifteen minutes[46,[100][101][102]. In this project, all the etch time is kept at 10 min.…”