This review paper presents a detailed analysis of the influence of high-velocity oxygen–fuel (HVOF) spraying parameters on the microstructure formation and performance characteristics of Cr₃C₂-NiCr coatings. Key HVOF parameters, including the spray distance, oxygen-to-fuel ratio, powder feed rate, and spraying temperature, are examined in relation to their impact on coating properties. Structural parameters such as density, porosity, adhesive strength, and microhardness, which determine the mechanical behavior of the coating, are analyzed. Special attention is paid to wear resistance mechanisms, adhesion to the substrate, and resistance to fatigue failure. Additionally, the thermal stability of the coatings, their coefficient of thermal expansion, and oxidation resistance are investigated. This study also evaluates the morphology and phase composition of the coatings under different HVOF spraying conditions. An overview of modern diagnostic techniques, such as electron microscopy and spectroscopy, is provided. Compared to traditional surface treatment methods, HVOF spraying offers superior coating density, higher adhesion strength, and enhanced wear and corrosion resistance, making it an effective solution for extending the service life of components. Based on the findings, this paper highlights promising applications of Cr₃C₂-NiCr coatings in the aviation, power engineering, and mechanical engineering industries, where high wear resistance and thermal stability are crucial.

Composite coatings based on chromium carbide (Cr₃C₂) and nickel–chromium alloys (NiCr) are widely used due to their unique properties, including high heat resistance, wear resistance and corrosion resistance. This article studies the structural–phase and physical–mechanical characteristics of Cr₃C₂-NiCr composite coatings applied by high-velocity oxygen fuel to E110 zirconium alloy. The HVOF method was chosen to create coatings with high adhesion to the substrate and excellent performance properties. Analysis of the microstructure of the cross-section showed the thickness of the modified surface layer from 75 to 110 μm, depending on the processing modes. Energy dispersive X-ray spectral analysis revealed the presence of elements Cr, Ni, C and O in the coating composition. Structural–phase analysis confirmed the formation of coatings with a high concentration of Cr₃C₂ carbide particles and NiCr (nickel–chromium) phases. The resulting composite coatings based on Cr₃C₂-NiCr had a significantly high microhardness, ranging from HV 1190 to HV 1280, and the friction coefficient varied in a significant range from 0.679 to 0.502 depending on the processing conditions. The maximum adhesion strength was 9.19 MPa per square centimeter.

Nowadays natural gas hydrates attract special attention as a possible source of fossil fuel. According to various estimates, the reserves of hydrocarbons in hydrates exceed considerably explored reserves of natural gas. Due to the clathrate structure the unit volume of the gas hydrate can contain up to 160–180 volumes of pure gas. In recent years interest to a problem of gas hydrates has considerably increased. Such changes are connected with the progress in searches of the alternative sources of hydrocarbonic raw materials in countries that do not possess the resources of energy carriers. Thus gas hydrates are nonconventional sources of the hydrocarbonic raw materials which can be developed in the near future. At the same time, mechanisms of methane clathrate hydrates formations have not reached an advanced level, their thermophysical and mechanical properties have not been investigated profoundly. Thereby our experimental modeling of the processes of formation of methane clathrate hydrates in water cryomatrix prepared by co-condensation from the gas phase onto a cooled substrate was carried out over the range of condensation temperatures 12–60 K and pressures 10⁻⁴–10⁻⁶ Torr. In our experiments the concentration of methane in water varied in the range of 5%–90%. The thickness deposited films was 30–60 μm. The vibrational spectra of two-component thin films of CH₄ + H₂O condensates were measured and analyzed.

Thin films of cryovacuum condensates of ethanol formed by condensation of the gas on a cooled metal substrate are studied by infrared spectrometry and thermal desorption techniques. The main purpose was to examine dynamic relaxation processes near the glass transition temperature and the transition from orientationally disordered to orders states in thin ethanol cryocondensate films. It was found that ethanol cryocondensate films formed by condensation at T = 16 K are in an amorphous state (ASE). Increasing the sample temperature to T = 80 K leads to the transformation of the ASE into a structural glass. With further heating to T = 97 K, the structural glass is converted into a supercooled liquid and at T = 105 K, a plastic crystal is formed.

This study investigates the formation of carbon dioxide clathrate hydrates under conditions simulating interstellar environments, a process of significant astrophysical and industrial relevance. Clathrate hydrates, where gas molecules are trapped within water ice cages, play an essential role in both carbon sequestration strategies and understanding of the behavior of ices in space. We employed a combination of Fourier Transform Infrared (FTIR) spectroscopy, mass spectrometry, temperature-programmed desorption (TPD), and Density Functional Theory (DFT) calculations to explore thin films of H₂O:CO₂ ice mixtures with varying CO₂ concentrations (5-75%) prepared by vapor deposition at temperatures ranging between 11 and 180 K. The study revealed the influence of CO₂ concentration and deposition temperature on the formation mechanism of diverse structures, including clathrate hydrates, polyaggregates, and segregated CO₂ groups. Spectral features associated with CO₂ encapsulation in clathrate hydrates were observed at 2335, 2349, and 3698 cm^-1 in the 5 and 15% mixtures after deposition at 11 K and after warming at temperatures above 100 K. The observed increase in CO₂ sublimation temperature to 145-155 K and co-condensation of CO₂ molecules at 172 K with water molecules at a pressure of 0.5 μTorr can be attributed to the encapsulation of CO₂ molecules within the robust hydrogen-bonded framework of the clathrate cages under specific conditions. These findings enhance our understanding of the intricate processes involved in clathrate and hydrate formation in CO₂ and H₂O mixtures, shedding light on their physical properties and the dependence of their specific characteristics on the formation method.

This article presents a review of current research on the use of molybdenum disulfide (MoS₂) and its composites as promising materials for energy storage systems and functional coatings. Various MoS₂ morphologies, including nanoflowers, nanoplatelets, and nanorods, are considered, as well as their effects on electrochemical properties and specific capacity. Particular attention is paid to strategies for modifying MoS₂ using carbon nanomaterials (graphene, carbon nanotubes, porous carbon) and conductive polymers, which improve electrical conductivity, structural stability, and durability of electrodes. The important role of chemical vapor deposition (CVD), which allows the formation of uniform coatings with high purity, controlled thickness, and improved performance characteristics, is noted. A comparative analysis of advances in the application of MoS₂ in sodium-ion batteries, supercapacitors, and microwave absorbers is provided. It has been shown that the synergy of MoS₂ with carbon and polymer components, as well as the use of advanced deposition technologies, including CVD, opens new prospects for the development of low-cost, stable, and highly efficient energy storage devices.