Structure and Physics Mechanical Properties of Multiperiod Vacuum-arc Coatings on the Basis of Two-layer System TiNx/ZrNx

Abstract

By methods of structural analysis (a precise X-ray diffraction method and raster electron microscopy) in conjunction with tests on physical and mechanical characteristics (hardness, elastic modulus, friction force and friction coefficient) comprehensive studies have been conducted. Such complex researches are the basis for optimization of properties of multiperiod systems TiNx/ZrNx by changing their structural states (structural engineering). The main parameters of changes were: number of layers (n) from 134 to 534 (at total coating thickness of about 10 microns) and magnitude of negative bias potential Ub. Formation of biphasic (TiNx and ZrNx) condition was revealed. On substructural level the most sensitive to Ub is micro-strained state. The growth of micro-strain with an increase numbers of ZrNx layers (at the greatest Ub -200 V) testifies about the determining contribution of irradiation of heavy Zr ions in defect formation at formation of coating. Is established that under optimal technological parameters of receiving of multiperiod TiNx/ZrNx coatings their hardness is in the range 40-50 GPa that corresponds to super hard condition. Dependence of penetration depth of indenter is revealed during testing in a pair of "diamond-multiperiod TiNx/ZrNx coating" and coefficient of friction on the ratio H/E, which characterizes the elasticity of material.