The role of monolayers thicknesses ratio for oxidation resistance of AlN/sinx magnetron Sputtered coatings

Abstract

Physically-vapor deposited transition metal nitride coatings based on MeN mononitrides of transition metal (Me=Ti, Zr, Cr, Al and others) are widely used in the industry as solid protective coatings. However, mononitride films often lose their protective role under harsh external conditions like friction, high temperatures, influence of corrosive media or irradiation. At the present, the multilayer film structures show considerable promise for improvement of the coatings operating abilities. In particular, multilayer coatings, where the layers of transition-metal nitrides alternate with layers of SiNx, are characterized by the mutual insolubility of these two phases and display good thermal and oxidation stability and properties [1–3]. The presence of a large number of interfaces between layers and fine-grained structure are the reasons of it. As it was shown in our previous studies, the resistance to high temperature oxidation of ZrN/SiNx and CrN/SiNx coatings depends on the thicknesses ratio of elementary layers [4]. In this work, the stability of AlN/SiNx coatings with different ratio of monolayers thicknesses upon annealing in air is investigated.