Phase composition and crystallite size study of multilayered transition metal films based on molybdenum and chromium nitrides

Abstract

The paper is focused on the deposition and study of multilayered transition metal nitride films CrN/MoN obtained by vacuum arc depo sition (Arc-PVD). Samples have from 12 up to 354 layers with total thickness of 8-15 mu m. Bilayer thickness of samples vary in range from 2.2 mu to 40 nm. Films have been studied by scanning electron microscopy (SEM) from cross-section view. Their elemental composition also has been studied by energy-dispersive X-ray spectroscopy (EDS). Characterization of the structure of multilayered CrN/MoN films have been performed using X-ray diffraction (XRD) analysis. Two main phases of cubic CrN and gamma-Mo2N have been identified. Grain size distribution was calculated from XRD analysis data. It was observed the decreasing of average grain size with decreasing of individual layer thickness. This feature of studied films may be important for characterization and prediction of their mechanical properties, such as hardness, elasticity, toughness etc. According to the Hall-Petch strengthening, deposited films with lower values of individual layer thickness may have higher values of hardness and, hence, exhibit better toughness, wear resistance and improved performance of coated tools.