Evaluation of Tribological Performance of TiN Films Doped with Copper Deposited by Magnetron Sputtering

Since their early investigations, TiN coatings have sparked considerable interest because of their remarkable mechanical properties, especially their prominent hardness (30–60 GPa) and oxidation resistance. They are mainly used to harden and protect cutting or sliding tools and occasionally for decoration. Small quantities of different ligands, including Ni, Cu, or Co, are added to improve the smooth performance of cutting tools. These alloying elements lead to the formation of nanocomposites, potentially altering their mechanical characteristics and imparting notable flexibility. In this context, this study focuses on the production of pure TiN and Cu-doped TiN thin films. Magnetron sputtering was used as a deposition technique, simultaneously sputtering Ti and Cu-targets, both with high purity (99.99%), and in a gas mixture of Ar and N 2 . X-ray diffraction, SEM, profilometry, nanohardness, and scratch test analyses were employed to characterize the TiN and TiN/Cu films. The results reveal that 3–4% of Cu content led to a slight decrease in hardness, while surface adhesion increased with the addition of copper. Furthermore, the elasticity of the doped films improved the strength and wear resistance of coatings with Cu compared to TiN films without added Cu.