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Durability and tribological tests of standard grades of high-speed steels and experimental single-carbide hard alloys with modified cobalt binder, created on the basis of the standard VK8 grade, under conditions of friction and turning of structural steels 45 and 12Х18Н10Т were carried out. The experiments were carried out for various cutting speeds and friction in order to determine the dependence of the optimal modes from the point of view of reducing the wear rate for cutting materials with different structural and thermodynamic characteristics. It has been experimentally established that high-speed steels with high values of thermal entropy have greater wear resistance in comparison with low-entropy grades, and cutting (sliding) speeds corresponding to minimal wear rates are higher for them. For experimental hard alloys grades characterized by greater thermal entropy values of the binder lower wear rates at optimal cutting speeds compared to the base alloy were also recorded; the values of the optimal cutting speeds for these materials are also higher. Thus, high-entropy cutting materials allow machining at higher speeds, while reducing the wear intensity.

The processes occurring at saturation of the surface with various elannotation The paper deals with issues related to the kinetics of saturation of high-density powder materials obtained by hot stamping (GS). The effect of surface treatment, temperature and time of saturation of the surface of highdensity powder materials with nitrogen and carbon is investigated. The graphs of the influence of these factors are given. The structures of the diffusion layer and the effect of the surface features of high-density powder materials on saturation with nitrogen and carbon are described. Comparative studies on the saturation of the surface layer at the SC of high-density powder materials and rolled steels have been carried out. It is established that the thickness of the diffusion layer on the iron powder is greater than that on low-carbon electrical steel and the magnitude of the difference slightly decreases with increasing temperature.

This article presents an experimental determination of the powder materials splicing surfaces’ quantitative characteristics obtained by hot processing. This study analyzes the hot deformed powder material’s microstructures. We consider what changes the powder grains have undergone and what are the single crystals of different sizes, a certain configuration and color, as well as the crystallographic planes’ direction with respect to the thin section plane. In the course of the work, spheroidization of particles and their coagulation due to the absorption of small particles by large particles have been observed. The influence of the initial particles’ size on the structure formation of powder alloys by using the homogenization features during sintering has also been investigated. The deformation character of the porous steel particles’ material compacts from two types of a mixture based on coarse and fine iron powder with different porosity is considered. As a result, after sintering, an increase in semi-finished products and a corresponding increase in porosity were observed. In this case, the effect nature of the dependence on the porosity of samples of powders of various sizes on plastic deformation is traced on thin sections of the porous semi-finished products. With a greater degree of compaction, the activation of the surfaces collapsing during hot stamping of pores and their rapid coalescence after reaching physical contact are detected. The work revealed that the investigated non-porous hot-deformed steel is almost uniform in structure due to the complete deformation of all particles of various sizes original iron powder. The clear boundaries of the particles’ coalescence surfaces on the studied samples are traced. In the course of this study, certain dependences of the splicing quality on interparticle contact surfaces during hot pressure treatment of powder semi-finished products and the properties of the obtained hot-deformed powder materials on the considered technological parameters [1, 2], for example, such as the particles’ size, determining the interparticle splicing surfaces boundaries length, differences in the mixture particles’ deformability, leading to a decrease in the volume of material deformed during hot processing pouring powder semi-finished products.

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