Structure and mechanical properties of Ti–Si–N ceramic nanocomposite coatings

We have synthesized a series of Ti–Si–N coatings with 0–20 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), θ–2θ 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 hardness of the present series of Ti–Si–N coatings was found to be less than 32 GPa.