Tribological study of TaTiN/TaTi multilayer films with hierarchical arrangement

Abstract

The tribological performance of the coatings depends on their properties like material, morphology, structure, among others. This work compares the tribological performance of two multilayers films of ceramic/metallic (TaTiN/TaTi) combination with a hierarchical morphology arrangement using DC-magnetron co-sputtering with Ta and Ti metallic targets controlling the sizes of their ceramic-layer thickness on the Ti substrate. These films had the configuration of the nano to microscales (NML) and micro to nanoscale (MNL) layers. The films had the structure combination of c-TaTiN, c-TiN, and α”-TaTi, with higher Nitrogen in the MNL coatings and higher intensity of LA vibrational mode in their Raman spectra. The XPS study showed that the MNL coating presented a higher metallic composition in the top layer than NML. Nevertheless, MNL film had a higher H and lower E* than NML coating due to the stress distribution by the multilayer arrangement. The MNL coatings showed higher elastoplastic deformation and reduced the presence of cracks and fractures of the layers. The Raman spectra of MNL coating presented a higher presence of Ta2O5 vibrational modes than the MNL film due to a tribolayer formed by debris accumulation.