Structure, Substructure, Hardness and Adhesion Strength of Multiperiod Composite Coatings MoN / CrN

Abstract

A comprehensive study of the influence of the thickness of the layers, Us and PN on the structural engineering to obtain high mechanical properties in multilayer composite MoN / CrN vacuum-arc coatings has been conducted by means of scanning electron microscopy with energy analysis, X-ray diffraction studies microindentation and scratch testing methods. It has been determined that in the studied PN  (2- 30)  10 – 4 Torr, the content of nitrogen in the coatings varies from 6.3 to 33 at. %, which leads even at the greatest nitrogen content to the formation of lower phase by nitrogen, -Mo2N and isostructural CrN with the vacant sites in the nitrogen sublattice. The increase of thickness of the layers applied on the substrate in a stationary state promotes the increase of nitrogen content. Along with this, the lowest microdeformation and the average size of crystallites are formed at Ub  – 300 V, which defines the achievement of greater hardness of 35 GPa and high adhesion strength, which resists the destruction, Lc5  187.6 N.