The influence of multilayer architecture on the structure and mechanical properties of WN_x/TiSiN coatings in comparison with WN_x and TiSiN single layers

Abstract

The present work deals with the comparison of selected properties of WNx/TiSiN multilayer and respective WNx and TiSiN monolithic coatings that were deposited at the same parameters. The effect of the multilayer architecture on the structure and mechanical properties of WNx/TiSiN multilayer was studied in detail. The multilayers and monolayers were fabricated on high-speed steel substrates by unbalanced direct magnetron sputtering from W (purity 99.95 %) and Ti80Si20 (purity 99.50 %) targets. The chemical composition and the cross-sectional morphology of multilayer and single-layer coatings were characterized by scanning electron microscopy (SEM) equipped with wave-dispersive X-ray spectroscopy (WDS). The structure was analyzed by X-ray diffraction (XRD). The hardness and Young’s modulus of multilayer and coatings were investigated using the nanoindentation method. Results showed that the WNx/TiSiN multilayer, possessing cubic W and TiN phases and a dense layered microstructure, showed slightly improved hardness (28.5 ± 3.5 GPa) and HIT/EIT parameter (0.087), as compared with the WNx and TiSiN coatings. It has been shown that the design of multilayered structure of WNx/TiSiN coating is a promising way to tailor the microstructure and properties of the hard coatings.