The dependence of the reaction rate on temperature and pressure is considered from the standpoint of chemical kinetics, and an attempt is made to explain the increase in friction force after a decreasing load on the contacting surfaces and attaining the minimum with an increase in the sliding velocity. Thermodynamic aspects of the transition state theory and the cases wherein the reaction itself causes resulting deviations from equilibrium are considered.

A significant number of different types of structural damages to structural materials, as well as all kinds of scenarios for their accumulation up to destruction, require not only the use of a significant arsenal of experimental methods of theoretical materials science and molecular physics, but also the development of corresponding mathematical models. These models perform two functions. On the one hand, they make it possible to give a reasonable interpretation of complex processes, and on the other hand, to give a forecast of the evolution of the material under specific operating conditions. Some features of describing the processes of degradation and destruction of materials, based on kinetic approaches are considered.

Приведены результаты исследований усталостной прочности конструкционных материалов стали Ст45 и высокопрочного чугуна ВЧ60-2 с плазменными покрытиями относительно большой толщины из порошковой композиции, представляющей собой жаропрочный сплав ЭП-109 (ХН56ВМКЮ) на никелевой основе и алюминиево-магниевый порошок Al–Mg. На основании проведенных экспериментальных исследований получены математические модели, описывающие закономерности влияния технологических режимов плазменного напыления на усталостную прочность исследуемых конструкционных материалов. The results of studies of the fatigue strength of structural materials of steel St45 and high-strength cast iron HF60-2 with plasma coatings of relatively large thickness from a powder composition consisting of a heat-resistant alloy EP-109 (KHN56VMKYU) on a nickel base and aluminum-magnesium powder Al–Mg are presented. Based on the conducted experimental studies, mathematical models describing the patterns of influence of technological modes of plasma spraying on the fatigue strength of the studied structural materials have been obtained.

The issues of the kinetic theory of strength and the influence of temperature and force factors on the accumulation of damage in materials are considered. Phenomenological models of the formation and the propagation of structural defects determine the strength, anticorrosive, tribotechnical properties of materials and the nature of occurrence of destruction processes during operation. The choice and the verification of a behavior model of materials allows us to reasonably apply methods to improve their operability and corrosion protection.

This paper provides the results of fatigue strength tests of structural materials including grade St45 steel and VCKh60-2 high-strength cast iron with plasma coatings. These coatings have a relatively large thickness and consist of the powder composition of EP-109 (KhN56VMKYu) heat-resistant nickel alloy and Al–Mg powder. Experiments have allowed deriving mathematical models to describe the patterns of the influence of the plasma spraying process modes on the fatigue strength of the tested structural materials.

Some features of the description of the evolution of processes of degradation and destruction of materials are considered, based on an analysis of changes in their energy state under the influence of various types of loading. The factors that determine the complexity of creating a generalized model of the destruction of materials of parts are noted, the main one of which is the search for the relationship between numerous interdependent parameters that characterize not only the loading process, but also the process of adaptation of materials to changing conditions of dynamic influences.

Objectives . To investigate the possibility of preventing hydrogen absorption into the functional structural materials of hydrogen-generating membrane electrode assemblies based on porous nickel, carbon black, and reduced graphene oxide with platinum–nickel and palladium–nickel nanoparticles. Methods. The hydrogen absorption into materials of membrane electrode assemblies of alkaline electrolyzers was evaluated using an electrolyzer with variable temperature, reagent feed rate, and gas content. Results. The study established the need to use reduced graphene oxide, in order to reduce hydrogen absorption and degradation of hydrogen-generating membrane electrode assemblies. Conclusions. The service life test results and performance of the designed variants of prototypes of membrane electrode assemblies with nanostructured electrodes based on reduced graphene oxide, preventing hydrogen absorption into functional materials and their degradation, demonstrated the creation of hydrogen generators with high energy efficiency shows potential.

This work considers issues related to modern geometrical ideas about the structuring at phase transitions in solids and liquids.

Issues related to a generalized description of the lubricant degradation, which ultimately leads to the degradation of the structural material during friction and cutting, are considered. The electrochemical interpretation of processes based on the theory of acids and bases is considered in the case when a lubricating medium is not a classical electrolyte.

Problems of the kinetic theory of strength and the influence of temperature and force factors on the accumulation of irreversible damage in materials are considered.

A new model of a laminar combustion process is constructed based on its thermodynamic analysis. Under controlled growth of temperature at the inlet to the combustion chamber, depending on the structure of the standard chemical potential, high-frequency oscillations of the thermal explosion resonance occur in the model. Resonance modes in the case of heat pumping are modeled, the nature of their origin is established depending on the structure of the standard chemical potential, and numerical experiments exhibiting these modes are presented.

Based on the material considered, assumptions are made about the dependence of the reaction rate on temperature, which should be properly taken into account in mathematical models of the tribochemical kinetics of external friction. From the perspective of tribochemical kinetics, the study of the dependence of the reaction rate on temperature is reduced to the need to explain the increase in the friction force after it decreases and reaches a minimum with an increase in the sliding velocity. In the context of the models studied, this behavior reflects the trend for a linear increase in temperature in the region of the topochemical reaction of the adhesive setting with an increase in the sliding velocity and a linear dependence of the decrease in energy and activation of the formation and growth of adhesive setting nuclei on the contact patches of friction surfaces.

The author’s method of thermodynamic analysis is used to single out two equations of state for the laminar combustion process: the classical Hugoniot adiabat, which determines the pressure, and the equation of state, which determines the entropy. This allows constructing a new mathematical model of the laminar process of vibrational combustion of a two-component mixture by closing the classical models of continuum mechanics. The model is phenomenological, which requires its verification. For numerical verification, the well-known experimental fact is chosen, the appearance of high-frequency acoustic vibrations described by B.V. Raushenbakh. The conditions for the origin of high-frequency oscillations are obtained in terms of the standard chemical potential. They can substantially disturb the combustion process and may cause a catastrophic break-up of the furnace of the engine structure. A numerical experiment established critical values of the standard chemical potential when high-frequency vibrations lead to destruction.

The efficiency of technological systems in production may be assessed in terms of the input and output resources. This method may be used in deriving digital twins for complex systems in design support.

The article considers the mechanisms of intensifying chemical reactions occurring in vortex layer devices. The competition of reagents used as oxidizing agents in water treatment and oxidizing agents appearing during the operation of vortex layer devices is considered. The article offers a description of wastewater treatment process kinetics both for the oxidizing process and the process caused by electrochemical (corrosive) synthesis of highly active reducing agents. The mathematical model is constructed and its analysis is given.

The nucleation and formation of one-, two-, and three-dimensional capture zones in contact with friction are kinetically analyzed. Data regarding extension, alternating flexure, and the growth of macroscopic cracks may be approximated by a quasi-Weibull distribution. The model of the inverse kinetic problem is experimentally verified.

This article discusses wear-preventive tribological coatings that increase the operational life of artillery, tank, and rifle barrels. Studies have been conducted using some of them. The presence of a sufficiently large scientific and technical reserve in the field of material science of heat-resistant alloys and antifriction antiwear coatings is noted.

The article analyzes the effectiveness of anti-friction coatings obtained by finishing anti-friction non-abrasive treatment (FANT), including processing in metal-clad technological media, in order to improve the performance of machine parts. The analysis of the application of coating technologies FANT on materials operating at elevated temperature and at high pressure, as well as with high values of energy fluxes in the environment, was carried out. The results of the application of various compositions of cladding elements and FANT technologies for various engineering products are presented. The results of studies of the use of FANT technologies developed with the participation of the authors confirm their high efficiency for improving the wear resistance of artillery gun barrel materials. Decrease in wear ranging from two to three times compare to regular technology. Field testing of anti-friction anti-wear coatings, carried out by specialists of the FSE SRI «Geodesia», confirmed the prospects of this direction for increasing the survivability of artillery barrels.