THE CHARACTER OF ENERGY DISSIPATION OF ELASTIC OSCILLATIONS DURING INTERNAL FRICTION STUDIES OF PLASMA MULTIPHASE COATINGS DEPENDING ON THEIR MICROSTRUCTUR

Abstract

Damping of elastic vibrations in materials with coatings of a complex microstructure with nanocomponents in the form of aerosols was studied. Simple and highly alloyed steels, as well as armco-iron, were chosen as the basis for research, and single- and multi-component powders were used for coatings. Coatings in the form of composite systems based on nanopowders of silicon dioxide SiO2 (aerosil), aluminum aerosil and titanaerosil (Al2O3∙SiO2, TiO2∙SiO2), designated as AlaL and TiaL, respectively, were also studied. These highly dispersed oxides (nanomaterials) were obtained by pyrogenic synthesis. A mixture containing Al2O3∙and ∙SiO2 powders was also used, the components of which were plated by the ionplasma method with microparticles of titanium Ti and aluminum Al – (Al2O3/Ti), (SiO2/Al). The analysis of the properties of the coating-base system is carried out on the basis of the calculation of the dislocation structure parameters, the estimation of the amplitude dependence of the internal friction (ADIF), which makes it possible to determine the mechanisms of the effect of the coating on the processes of destruction and deformation and the conditions of the effect of the coatings on the processes of strengthening or strengthening of the base material. Microstructural parameters were determined – the amplitude of microplastic deformation (γ″kr), the parameters of the dislocation structure of the coating and the surface layers of the base (с1, с2), which allow us to assess the role of the coating in the processes of CM destruction. The increase in the ability of materials to dissipate the stored elastic energy after the application of plasma coatings occurs mainly for materials with those coatings, the structure of which has a large length of interphase boundaries. This is shown on the example of multicomponent coatings containing nanocomponents in the form of nanopowders. The application of the coating introduces fundamental changes to the defective structure both in the surface layers of the material adjacent to the contact zone and in the deep layers in the volume of the main material.