In the work, taking into account the state of the issue in the field of applying multilayer heat-shielding and wear-resistant coatings, directions of research are substantiated. The objectives of the development are: improvement of powder materials containing zirconium dioxide partially stabilized with yttrium oxide for plasma deposition of heat-shielding coa-tings; improvement of powder materials containing oxide ceramics and nickel-based alloys for plasma deposition of wear-resistant coatings; development of technological parameters of plasma spraying and subsequent processing by the effects of compression plasma on the coating; analysis of the quality of protective coatings obtained using the optimal technology by studying their structure and physical and mechanical properties. The ZrO2 – 7 % Y2O3 particles contain the predominant tetragonal Y0.15Zr0.85O0.93 phase, monoclinic and cubic ZrO2 phases, and the Al2O3–TiO2–Ni–Cr–Al–Y–Ta composition contains the Cr1.12Ni2.88 phase of the nickel-based solid solution, the a-Al2O3, g-Al2O3 phases, and the orthorhombic phase of titanium oxide TiO2 that contribute to its wear resistance. subsequent optimization of technological parameters for the process of plasma spraying of multilayer heat-shielding and wear-resistant coatings. Technological parameters for the process of plasma spraying of multi-layer heat-shielding and wear-resistant coatings are investigated with subsequent optimization. The optimization criteria were the utilization factor of the sprayed powder material and the structure of the coatings. The influence of the spraying distance on the values of operational characteristics of the formed plasma coatings on Al2O3–TiO2–Ni–Cr–Al–Y–Ta has been studied. The obtained results of controlling the phase composition of coatings by varying the chemical composition of powder materials are presented. In the process of deposition, the differences in the phase composition of the formed material are the more significant, the more inhomogeneous the distribution of elements in the initial powder material. Tests have been carried out for cyclic testing in an oven at a maximum temperature within 1300 °C of heat-shielding coatings to determine their heat resistance. They proved the influence of the phase composition of the formed coatings on their ability to withstand high-temperature oxidation.

The basic principles of construction are formulated in the work and a description of the technological process of hot briquetting of ferrous metal waste as a way of converting fine metal particles into a dimensional semi-finished product of a given size and chemical composition is given. The description of equipment for the implementation of this process with highly efficient non-oxidizing heating and complete safe neutralization of flue gases is given. The results of melting of hot-pressed briquettes in various melting units are presented. It is shown that briquettes cleaned from coolant with a density of 6500–7100 kg/m3 are full-fledged substitutes for bulk scrap. Recommendations and a feasibility study on the feasibility of introducing the hot briquetting process into production at the enterprises of the bearing, machine-building and metallurgical industries, followed by the use of hotpressed briquettes to produce cast billets for their own purposes, are given.

The simulation of the chip heating process in the zones of gas-flame and induction heating of a continuous muffle furnace has been carried out. The mechanisms of heat transfer (conductive, convective, radiative) that have a conjugated character are considered in the approximation of interpenetrating continuums in the absence of any noticeable influence of filtration processes under conditions of a highly porous chip medium. As a result of the analysis of heat and mass transfer in the porous chip body and the working space of the furnace, a system of equations was obtained for calculating temperature and concentration fields and fields of thermal radiation intensity depending on the specified furnace productivity, natural gas consumption, and oil concentration in the coolant. The system of equations, which is a model of heat and mass transfer processes, is closed and allows us to solve the problem posed – to determine the heating temperature of the chips at the exit from the gas-flame heating zone, the composition and residual content of the liquid phase in it, and also to find the optimal height and temperature of the inductor muffle in induction heating zone, dimensions and electrical parameters of the inductor.

The description of the device and principle of operation of the continuous muffle furnace for hot briquetting of chip‑powder dispersions of ferrous metals is given. A distinctive feature of this device is the presence of two systems of gas‑flame and induction heating, as a result of which the achievement of the specified charge heating temperature is guaranteed with the complete removal of the liquid phase. The oil component of the coolant is used to create a protective hydrocarbon atmosphere that provides non‑oxidizing heating of the metal, as well as to obtain a carbon coating, which, in addition to protective functions, acts as a lubricant in the hot briquetting process. Subsequent combustion of oil vapors in the furnace leads to significant savings in natural gas. A furnace built according to this principle has the smallest dimensions and the highest technical and economic characteristics.The simulation of the chip heating process in the zone of loading into the furnace is carried out. The dependences of the temperature of the chips at the outlet of the screw feeder on the temperature of the flue gases at the inlet for the mass fraction of coolant in the chips of 10 % and various fractions of oil are obtained. It has been established that during the heating of the chips in the loading zone, phase transformations of the coolant do not occur, the charge heating temperature does not exceed 100 °C.