Microstructure and mechanical properties of nanostructured Ti-Si-N coatings.

We have synthesized a series of Ti-Si-N coatings with 0 to 20 at. % Si by high-density plasma-assisted vapor-phase deposition. Composition, structure, and atomic short-range order were characterized by Rutherford Backscattering Spectrometry (RBS), Transmission Electron Microscopy (TEM), {Theta}-2{Theta} X-ray Diffraction (XRD), and X-ray Absorption Near Edge Structure (XANES) spectroscopy. The mechanical properties of these coatings were characterized by instrumented nanoindentation, and compared to those of B1-TiN. Our experiments show that the present series of Ti-Si-N coatings are nanocomposites, consisting of a nm-scale mixture of crystalline titanium nitride (TiN) and amorphous silicon nitride (a-Si:N). The mechanical response of the present series of Ti-Si-N coatings was found to be essentially independent of the Si composition, and similar to that of B1-TiN.