Physical properties evolution on ternary and quaternary carbonitride coatings

Abstract

The ternary and quaternary multilayers were synthesized via physical deposition processes. The aim of this work is to determinate the evolution of mechanical behavior in TiCN/TiNbCN multilayers systems as a protective coating. The multilayers characterized by X-Ray Diffraction (XRD) exhibited the crystallography orientation (111) for TiCN and TiNbCN phases. The multilayer periodicity and coherent assembly were determined by transmission electron microscopy (TEM). The mechanical properties, such as hardness and elastic modulus, were determined by nanoindentation measurements. The internal stress analysis in multilayer hard coatings, made possible by radius of curvature coatings using profilometry, found a stress reduction around 80% when the number of layers (n) were increased from n = 1 to n = 200. Changes in the increase of size of indentation track and growth of crack length allowed the determination of the increase in the fracture toughness around 85% as a function of bilayer period from Λ = 1.5 μm to Λ = 15 nm. Finding a direct relationship among reduction of residual stress, evolution of mechanical properties, and fracture toughness when the bilayer number has been changed, indicates that multilayer coatings may be a promising material for mechanical industry.