Experimental investigation of structural, wetting, mechanical and Tribological properties of TiZrN thin films deposited by magnetron sputtering

Abstract

-TiZrN thin films were deposited on Si (100) wafers and XC100 steel substrates by reactive R.f. magnetron sputtering using titanium and zirconium targets in an Ar-N2 mixture atmosphere to evaluate the effect of varying Zr content (0 to 22.2 at.%), on the film structure, surface wettability, hardness and wear resistance. The presence of different phases such as TiN, ZrN, and ZrO2 were confirmed by XRD analysis. Results showed that, the lattice parameter and film thickness increased while the crystallite size and average roughness decreased with increasing Zr content. Total surface energy between the film surface and testing liquids decreased with the addition of Zr. TiZrN film containing 18.3 at.% of Zr showed the lowest surface energy of 38.7 mN/m, indicating its hydrophobicity. The nanoindentation measurements, friction and wear tests showed that the TiZrN thin film containing 18.3 at.% of Zr had the best tribo-mechanical performance. The TiZrN (18.3 at.% Zr) film exhibited the lowest friction coefficient (0.31), and the lowest wear rate (6.65 × 10−5 mm3/Nm), which corresponds to the highest H/E ∼ 0.139, and H3/E2 ∼ 0.49 GPa ratios. The improvement in the tribo-mechanical properties is attributed to the solid solution strengthening due to the incorporation of Zr atoms in TiN system, which results in the highest hardness of 25 GPa for TiZrN (18.3 at.% Zr) film.