ANALYSIS OF ENERGY COSTS IN THE FORMATION OF PLASMA COATINGS AND IN DESTRUCTION UNDER LOAD CONDITIONS

Abstract

To evaluate the adhesion energy of interacting surfaces during plasma spraying of powder materials in the ‘base – plasma coating’ system, the proposed approaches are primarily thermodynamic and electron-statistical. An analysis of surface properties and an assessment of the processes of formation of strong bonds and their destruction under plasma spraying conditions were carried out using computational and experimental research methods. The solutions obtained, in general, made it possible to calculate the values of adhesion energy and force, as well as the strength of the bond between the coatings and the base. The calculated values of adhesion work Uа were calculated based on a physical model that takes into account such sputtering parameters as gas flow velocity, particle velocity and size, the ratio of the geometric parameters of the sputtered particles and the micro-relief of the surface layers of the base material, and their physical and mechanical properties. from the parameters of the sprayed material particles The presented methodology for assessing the nature of destruction and crack resistance of the obtained composite materials is based on consideration of the energy balance of the system at the moment of crack initiation. The aim of research in this area is to determine the crack resistance coefficients K1c and the intensity of released energy G1c when considering the energy balance at the moment of crack formation in different areas of the base-coating system. By introducing criterion dependencies into the calculation, it is possible to predict the nature of system failure based on the ratios of crack resistance coefficients K1c and certain dimensionless parameters that collectively describe cracking, delamination, and deformation processes. The coatings studied in the work showed high values of fracture toughness (G1c and K1c). It has been established that systems with ultradisperse nanoparticles are characterised by increased crack resistance. Nanoparticles in a multiphase coating contribute to the formation of strong cohesive and adhesive bonds both in the coating itself and in the interphase region.