International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The most common coatings for metalworking tools include titanium nitride, titanium carbide, titanium carbonitride, zirconium nitride, zirconium carbide, zirconium carbonitride, compounds based on chromium, titanium, aluminum, diamond-like coatings that are formed in vacuum using PVD, CVD, PCVD methods or a combination of the above methods. The current trend in the deposition of vacuum coatings is the production of multifunctional coatings, which can significantly increase operational characteristics compared to the starting materials. To form multifunctional coatings, the creation of “sandwich” structures is used, since each layer performs various functions – forming, antiwear, anticorrosion. Thus, the use of a composite multilayer coating containing layers of titanium nitride, titanium, diamondcontaining compounds with a thickness of one layer from 0.1 to 2 microns makes it possible to increase the wear resistance of a metalworking tool by 1.5-5 times.

The morphology of the coatings has a significant effect on the tribological characteristics of the contacting bodies. Depending on the relief of the surface layers of the coatings, the resistance of the modified substrates to corrosion is dete rmined. It is known that the processes of friction and corrosion have a decisive influence on the performance of products. To reduce the influence of these processes, various protective coatings are used, including those formed by the method of electrospark alloying. The aim of th is work was to study the morphology and structure of electrospark coatings formed by layer-by-layer electrospark alloying. In the course of the studies carried out, it was found that these coatings are morphologically heterogeneous, with a large number of cracks and splats.

Physicomechanical and adhesion characteristics, specific surface energy of vacuum coatings formed on high-speed steels of the P6M5 type subjected to processing at cryogenic temperatures are investigated. The structural transformations occurring in vacuum coatings formed on steel substrates with subsequent processing at low temperatures were studied. A change in the tribological characteristics of titanium nitride coatings during subsequent processing in a cryogenic liquid is shown.

This article describes part of the results obtained during the development of a new generation of vaccine adjuvants based on nanostructured hydroxyphosphates of tunable composition and physicochemical characteristics. Colloidal gels of ferric hydroxyphosphates of various iron/phosphate ratios were prepared by precipitation techniques, sterilized by autoclaving and analyzed by transmission electron microscopy (TEM) and dark-field optical microscopy. The obtained materials were composed of a network of amorphous nanoparticles (<20 nm in size) that were aggregated into micron-sized structures in physiological saline. Preliminary adsorption experiments indicated the ability of the obtained materials to adsorb protein substances, which is an important prerequisite for their potential application as vaccine adjuvants and further optimization of the production process to achieve reproducibility of the physicochemical characteristics.

In the present work, the adhesion and physico-mechanical characteristics of heat-resistant vacuum coatings formed on steel substrates are investigated. An increase in the values of adhesion and physico-mechanical parameters of coatings formed from multicomponent compounds is established. The tribotechnical characteristics of coatings based on chromium carbonitride have been studied.

The paper describes part of the results of the first year of the IAEA Coordinated Research Project F23032, Contract № 20567 on “Studying Side-Effects of Gamma Irradiation Treatment for Disinfestation of Cultural Heritage Artefacts”. Calf leather, calf suede and pig skin patterns were selected and analyzed by Scanning electron microscopy (SEM), and Thermal gravimetric analysis (TGA) before and after the gamma-irradiation treatment with 5 kGy, 10 kGy and 15 kGy absorbed doses at low dose rate. The irradiation of the leather materials was performed in the gamma-irradiation facility BULGAMMA based on JS-850 60Co type gamma irradiator at Sopharma JSC. No significant changes in the leather morphology and thermal decomposition were observed as a result of the gamma-irradiation treatment. Conclusions on the applicability of gamma-irradiation treatment for preservation of leather items with insecticide and fungicide doses were done.

Investigated the mechanisms of interfacial interactions in composite materials based on thermoplastic matrices modified with dispersed particles of silicon and carbon-containing compounds with high energy activity. It was found that the laser treatment of particulate and fibrous particles occurs comprehensive modification of the surface layer, which consists in shaping the development of the morphology of the surface layer and increase its energy. For the modification of thermoplastic matrix including high-viscosity (polyamides, PTFE) prospectively the use of dispersed fragments of carbon fiber (CF) fraction 50-150 microns, subjected to the effects of a short pulse laser, having developed the morphology of the surface layer and the presence of defects through thermal degradation. When using this modifier in an amount of 5-30 wt.% for filling PA6, PA66, PTFE provides increased of parameters deformation and strength characteristics due to the increased mechanical component adhesive interaction at the interface of "matrix-filler". An additional effect is realized in the processing of the surface layer of CF fluoride compounds oligomeric or polymer-oligomeric structure. The modified fluorinated hydrocarbon components fragments CF when laser pulse processing are exposed to the active low molecular weight products ablation, so that the surface layers are formed with a high affinity to the matrix polytetrafluoroethylene. The complex method of modifying CF is effective for highly filled fluoro composites containing 25-35 wt.% of carbon fillers due to the decrease in the probability of formation of cluster structures of the filler particles. Dispersed particles silicate (clay, tripoli, talc) and carbon (graphite, carbon black, shungite) when exposed to laser radiation susceptible to degradation with the formation of nanoscale fragments in a moving layer, thus increasing their activity in the processes of the interfacial interaction in the formation of composites based on oligomeric and polymeric matrices.

Are investigated mechanisms and kinetics of structural transformations polymeric substrates and of disperse particles fillers and modifiers exposed defocused laser radiation with energy in the range of 1.5 to 6 J. Installed effect of hardening the thermoplastic matrices (polyolefins, polyamides, of polyesters) when exposed to short laser pulses on a film sample thicknesses of 50-200 microns. The methods of structural analysis (IR spectroscopy, X-ray diffraction, DTA) showed, that the predominant mechanism of manifestation hardening effect is the formation of nano-sized structures in the film sample volume due to leakage of recrystallization processes. When exposed to laser radiation to disperse and fibrous particles of silicates, graphite, schungite, carbon fibers is implementing a complex effect of increasing the dispersion and the formation of advanced morphology of the surface layer with an increase in the proportion of nano-sized fragments whisker and lamellar habitus. When laser irradiation of fibers fragments formed developed morphology of the surface layer, due to the occurrence of thermal degradation processes that lead to the appearance of cracks and of globular indentations. Spectroscopy method of thermally stimulated currents (TSC – spectroscopy) established the effect of changing the energy state of the surface layers of substrates and particulate modifiers, which are characterized by extreme values of magnitude TSC – currents in the temperature range 193-523 K. The combined effect of energy and morphological factors provides the effect of increasing the activity of modifying components subjected to the laser processing. Changing the energy state of the surface layer of the polymer substrate has a beneficial bactericidal effect, increases the effectiveness of antiseptic treatment of medical devices used in medical practice. Are presented examples of the practical use of the established laws when creating polymer composites for metal-polymer systems for various applications.

Investigated the features of the structure of the thin-film coatings based on polymeric and oligomeric matrix formed by dipping, spraying or rubbing. It was found a significant effect of energy substrate parameters and components of the coating on the mechanisms of interfacial interactions that determine the parameters of strength, tribological and protective coatings. The active layer morphology of the surface of the substrate formed by mechanical, laser or chemical influence, characterized by the presence of low-dimensional components of different habitus, which affect the energy and mechanical component adhesive strength. By managing service parameters of composite material components on the basis of polymeric and oligomeric matrix manages to change the mechanisms of formation of coatings on metal substrates of carbon steels and non-ferrous metals. Coatings based on the thermal ablation of PTFE products are effective in the process of running heavy-duty friction units and their operation at reversing the motion. Installed effect Nanophase formation regions in the volume of the coating, which help to increase their durability in friction without external supply of lubricant.