G. V. Kozhevnikova, S. S. Dubenets (State Scientific Institution «Physico-Technical Institute of the National Academy of Sciences of Belarus», Minsk, Republic of Belarus); V. Ya. Schukin (Scientific and Technological Park of BNTU «Polytechnic», Minsk, Republic of Belarus); D. A. Kozhevnikov (JSC «Peleng», Minsk, Republic of Belarus)

Phenomenological deformation theory of destruction of metals during plastic flow

The phenomenological deformation theory presented in the article is based on the V. L. Kolmogorov’s theory of fracture. It is determined that the dependence of plasticity on the stress state is realized by means of its two independent parameters: the average stress and the parameter of the third stress tensor invariant. It is proposed to plot the dependence of the limit value of the accumulated deformation on the stress state in the form of a plasticity surface. It is shown that the deformation nature (unidirectional monotonic, multidirectional monotonic, non-monotonic) changes the material plasticity. The effect of damage accumulation nonlinearity is described.
Keywords: plastic deforming; fracture of metal; plasticity; damage accumulation; cross-wedge rolling.

A. I. Kanareykin (Russian State University for Geological Prospecting (MGRI), Moscow)

Theoretical substantiation of the study of thermal resistance of brittle materials by induction heating

The existing experimental methods do not allow us to accurately determine the limiting temperature stresses that cause the destruction of brittle bodies. In this paper, a theoretical justification of a method of testing for thermal resistance, similar to the method of radiation heating, is proposed. The use of the induction heating method itself makes it possible to control the heating temperature with good accuracy, which avoids overheating of the product, evenly and quickly heat the part to the desired temperature, and also with the chosen method it is possible to completely eliminate the appearance of smoke, oil pollution and strong fumes. In this case, external heating of samples of electrically conductive materials is carried out by high-frequency currents, which significantly expands the possibilities of obtaining representative experimental results and simplifies the experimental technique.
Keywords: thermal resistance; electromagnetic wave; eddy currents; penetration depth.

V. V. Mironenko, M. V. Lavrenteva (Irkutsk National Research Technical University, Irkutsk)

Derivation of functions for calculating the main parameters for the use of a movable clamp when changing the geometry of the part

The article highlights the problem of fast search of technological parameters of the process of defect-free shaping of cuts with elastic medium using movable clamping technology. A method based on the analysis of the parameters of the object model in three-dimensional space and the application of one of the original methods of regression analysis for the analysis of unknown values of regression values by sample characteristics is proposed. On the basis of power–type functions and combinations of functions of the first degree, functions for the parameters are derived: volumetric deformations, general plane deformation, stresses of shape change. These functions were superimposed on the original values and using the method of parametric statistics determining the presence or absence of a linear relationship between two quantitative indicators, the correlation relationship between these values was determined. An assessment of the tightness of the connection of the calculated values was carried out. As a result of the analysis, formulas are derived for calculating the main technological parameters for the design of a movable clamp and which can be used to quickly recalculate them.
Keywords: shaping by elastic medium; calculation of technological parameters; correlation of values; least squares method.

S. N. Sergeenko, D. A. Boshkanets (Platov South-Russian State Polytechnic University (NPI), Novocherkassk)

Technologies of selective laser melting of metal alloys

Technologies of selective laser melting of metal alloys are considered in an analytical review. The dependence of the characteristics of the synthesized product on the condition of the initial powder and technological parameters of the process of selective laser melting is shown. It has been established that the use of pressure treatment makes it possible to eliminate porosity in synthesized objects. Recommendations for optimizing the process of selective laser melting are given.
Keywords: powder metallurgy; selective laser melting; hot isostatic pressing; heat treatment.

Yu. N. Loginov (Ural Federal University named after the First President of Russia B. N. Yeltsin, Yekaterinburg), N. N. Zagirov, E. V. Ivanov (Siberian Federal University, Krasnoyarsk)

Model of an aluminum sponge bar sealing at its drawing and the influence of a die angle

The finite element method was used to simulate the drawing process of a porous rod made of aluminum alloy shavings. The stress-strain state during drawing through dies with the angles of inclination of the generatrix 8 and 13° is considered. It was revealed that with a small taper of the die, less uneven deformation is observed. With an increase in the taper, the uneven distribution of stresses, shear and volumetric deformations increases. In the latter case, a zone of material loosening may appear.
Keywords: drawing; porosity; density; stresses; deformations; finite element method.

G. M. Tokin (PJSC Rocket and Space Corporation Energia named after S. P. Korolev; National Research Technological University «MISiS», Moscow)

Formation of islet pellicles of bismuth selenide

Bismuth chalcogenides are promising materials with highly efficient thermoelectric properties that can make a great contribution to the electronics industry, spintronics, and quantum computing. These materials are used in integrated thermoelectric cooling devices. Being topological insulators, these materials with an insulating volume and topologically protected states on the surface can be used in various fields. In this work, we consider the formation of nanoscale islet pellicles of bismuth selenide by incongruent evaporation. Such thin films are of great interest due to the fact that they belong to the class of topological insulators, so they have the properties to conduct a spin-polarized electric current only over the surface, and control of this current makes it possible to reduce heat generation, increase speed and information transfer rate.
Keywords: spintronics; island films; topological insulator; nanomaterials.

I. I. Gulmadov (Polzunov Altai State Technical University, Barnaul)

Improving the mechanical characteristics of modified carbon fiber with various carbon fillers

In this paper, the influence of modifiers on the strength characteristics of carbon fiber plastics is experimentally proved. The mechanical characteristics of samples in the form of a rod made of modified carbon fiber reinforced plastics with different carbon fillers are determined. The research method concerns the determination of tensile strength and tensile modulus. It is shown that when modifying polymer resins, the mechanical characteristics of carbon fiber rods with modifying polymer resins increase by a factor of two or more relative to steel cores and by one and a half compared to other composite materials.
Keywords: modification; carbon nanotubes; strength characteristics; carbon fiber; epoxy resin.