Influence of the number of bilayers on the mechanical and tribological properties in [TiN/TiCrN]n multilayer coatings deposited by magnetron sputtering

Abstract

In this work the influence of the number of bilayers was studied on the mechanical, tribological and electrochemical properties of multilayer coatings [TiN/TiCrN]n as a function of the number of bilayers n = 1, 25 and 50, deposited by magnetron sputtering. By Xray diffraction (XRD), a cubic crystal structure centered on the faces (FCC) was determined for all coatings and an increase in the compressive stresses that were generated during the deposition process was found by perfilometry; Atomic force microscopy (AFM) determined that by increasing the number of bilayers, the roughness decreased, due to an increase in the density of the system. By nanoindentation it was found that the hardness (H) and the modulus of elasticity (E) increased as the number of bilayers did. By Pin on disk a decrease in the coefficient of friction was observed as the number of bilayers was increased, which was related to the increase in hardness and the reduction of roughness. The results of EIS and Tafel for the electrochemical properties, determined that the corrosion rate decreased due to the fact that a greater barrier to the passage of the electrolyte towards the substrate is promoted when the number of bilayers increases.