ANALYSIS AND COMPARISON OF MECHANICAL AND CHEMICAL PROPERTIES OF PROTECTIVE COATINGS OBTAINED AT DIFFERENT COMBINATIONS OF "TARGET – SUBSTRATE"

The effect of different combinations of the "target-substrate" on the mechanical and chemical properties of protective coatings obtained by ion-plasma treatment has been studied. The widespread use of ion-plasma technology for strengthening products is constrained by the imperfection of equipment, the lack of sufficient theoretical and experimental research for control and regulates the physical properties and technical parameters of the process. Eliminating these problems is possible based on further research and new solutions in the field of strengthening technology. For research in this direction, an experimental ion-plasma setup was used with software for regulating and controlling energy, dose, concentration of implanted ions, working gas pressure, coating thickness. The effective technique to improve the quality of the steel tool working surface has been applied, which made it possible to carry out mass transfer of alloying elements by ion-plasma surface treatment. Due to the controlled low-temperature two-stage ionization of nitrogen atoms and alloying elements in the reaction volume, the iron crystal lattice was saturated with implanted ions and carbonitride phases of the alloying elements, which are responsible for increasing hardness, wear and corrosion resistance. The optimal parameters of the implantation process (Us=25 kV, Is=35 mA, D=4.01·1,017 cm-2 per hour) were revealed, which made it possible to achieve an improvement in the surface properties of structural carbon, structural alloyed, tool steels. The relationship has been established between the service life of the products and the surface properties obtained after implantation. An increase in the service life of products with TiN coating (1.5–3 times), CrN (1.9–6 times) and ZrN (3–12 times) in comparison with uncoated products is shown. An analysis was conducted and the most effective variants of combinations "target ‒ steel substrate" for practical application of protective coatings were determined. The use of relatively inexpensive steel products with enhanced strength characteristics has economic benefits for the manufacturer and is one of the trends in modern productio