The corrosion resistance and hydroabrasive resistance of the developed epoxy composite coatings are investigated in this paper. The analysis of the penetration index change after τ = 50–150 days of immersion in a water medium and 10% sulfuric acid solution is carried out. The optimal ratio of the modifier and nanodispersed (Si₃N₄, Al₂O₃, AlN, and TiN) and fibrous (viscose, polyamide, matka silk, rong, and cashmere) fillers in the epoxy binder is determined. It was allowed to slow down the process of electrochemical reaction on the metal surface. The penetration of aggressive media in such a coating during the time t = 150 days is 0.8–2.8%. It is 1.5–2 times lower than the similar indexes of the initial epoxy matrix. The rational combination of the fibrous filler (wool, acrylic PAN, and cashmere), modifier, and nanodispersed (Si₃N₄, AlF₃, IH, and ZrH) filler in the epoxy binder is found, which allows to provide optimum indexes of wear rate. The wear rate under the action of a hydroabrasive of such a coating is I = 0.20%, which is 4 times lower than the similar indexes of the initial epoxy matrix. The wear mechanism of such coatings is caused by the physical and mechanical processes of microcutting and plastic deformation of the surface layer of the material.

The paper presents the results of studies of the physical and mechanical properties of materials: compressive failure stress, tensile failure stress, impact strength, and residual stresses in the material. To determine these parameters, we used modern methods of analyzing experimental studies, neural networks, to ensure a high measurement accuracy. Particular attention is paid to the research of the impact strength of residual stresses in the material, which allows for predicting the behavior of products in service. Impact toughness is one of the main indicators for evaluating materials that are operated under complex stress–strain conditions. It is proved that the values of both the compressive and tensile destructive stresses, impact strength, and residual stresses significantly affect the ability of the material to resist fracture under the action of both static and dynamic alternating loads. Critical values of residual stresses have been determined, the excess of which reduces the resistance of materials to fracture. The research has established the regularities of residual stresses and their magnitude in materials with different structural organizations. The research results are important from a scientific and technical point of view for the creation of new composite materials with high resistance to fracture, which will increase the operational reliability of the product as a whole.

Difficult, extreme operating conditions of parabolic antennas under precipitation and sub-zero temperatures require the creation of effective heating systems. The purpose of the research is to develop a multilayer coating containing two metal-ceramic layers, epoxy composite layers, carbon fabric, and an outer layer of basalt fabric, which allows for effective heating of the antenna, and to study the properties of this coating. The multilayer coating was formed on an aluminum base that was subjected to abrasive jet processing. The first and second metal-ceramic layers, Al₂O₃ + 5% Al, which were applied by high-speed multi-chamber cumulative detonation spraying (CDS), respectively, provide maximum adhesion strength to the aluminum base and high adhesion strength to the third layer of the epoxy composite containing Al₂O₃. On this not-yet-polymerized layer of epoxy composite containing Al₂O₃, a layer of carbon fabric (impregnated with epoxy resin) was formed, which serves as a resistive heating element. On top of this carbon fabric, a layer of epoxy composite containing Cr₂O₃ and SiO₂ was applied. Next, basalt fabric was applied to this still-not-yet-polymerized layer. Then, the resulting layered coating was compacted and dried. To study this multilayer coating, X-ray analysis, light and raster scanning microscopy, and transmission electron microscopy were used. The thickness of the coating layers and microhardness were measured on transverse microsections. The adhesion strength of the metal-ceramic coating layers to the aluminum base was determined by both bending testing and peeling using the adhesive method. It was established that CDS provides the formation of metal-ceramic layers with a maximum fraction of lamellae and a microhardness of 7900–10,520 MPa. In these metal-ceramic layers, a dispersed subgrain structure, a uniform distribution of nanoparticles, and a gradient-free level of dislocation density are observed. Such a structure prevents the formation of local concentrators of internal stresses, thereby increasing the level of dispersion and substructural strengthening of the metal-ceramic layers’ material. The formation of materials with a nanostructure increases their strength and crack resistance. The effectiveness of using aluminum, chromium, and silicon oxides as nanofillers in epoxy composite layers was demonstrated. The presence of structures near the surface of these nanofillers, which differ from the properties of the epoxy matrix in the coating, was established. Such zones, specifically the outer surface layers (OSL), significantly affect the properties of the epoxy composite. The results of industrial tests showed the high performance of the multilayer coating during antenna heating.

The article investigates the causes of surface degradation in the “stationary shaft–bushing” tribological pair of the roller assembly of a diesel engine fuel pump plunger in a heavy-duty truck, operating under increased loads and boundary lubrication conditions. A surface damage passporting methodology was applied, including analysis of microhardness, surface roughness, geometrical accuracy, and structural transformations within surface layers of the components, supplemented by elements of X-ray diffraction analysis. It was established that the dominant wear mechanism is hot scuffing (adhesive wear of the second kind), driven by irregular lubricant supply, chemical affinity of the materials of both components (bearing steel 100Cr6/ШХ15), localized load concentration, and the stationary configuration of the shaft. The formation of secondary hardened “white layers” was observed, indicating thermal overloading and a reduced load-bearing capacity of the surface layers after prolonged service. A set of design, technological, and operational measures is proposed to improve the reliability and durability of this friction pair.