KSHP. OMD №8-2023

V. N. Chudin, V. I. Platonov (Tula State University, Tula)

Upper limit calculation of power crimping mode with local heating

Ratios for calculating the crimping process with local heating of pipe blanks under conditions of viscoplastic deformation are proposed. The workpiece material is assumed to be anisotropic. The energy calculation method based on deformation kinematics is used. The kinematics are calculated with use of a discontinuous field of displacement velocities. The power on the surface of the velocity discontinuity is determined variationally. The dependence of pressure on anisotropy and speed of the crimping process is shown. Calculated results and product samples are presented.
Keywords: viscoplasticity; kinematics; speed; power; pressure.

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

A method for studying the thermal strength of brittle materials in a complex stress state using induction heating

Mechanical testing of brittle materials under complex stress conditions is very time-consuming and requires appropriate technical support. In most cases, the deformation coefficient of the part when working with induction installations is minimal. Since the distribution of heating in induction installations occurs as evenly as possible, this circumstance avoids the unpleasant consequences of uneven expansion of the part and minimizes the percentage of defects in the work. The proposed method of testing samples of brittle materials under conditions of thermomechanical loading differs favorably from the known methods of testing by the simple shape of the samples and the absence of the influence of grips on the test results.
Keywords: induction heater; thermal resistance; temperature field; temperature stresses; cylinder.

A. N. Martynenko (Donetsk National Technical University, Donetsk)

Method for predicting the melting temperature of multi-element alloys

The work is devoted to the development of a method for predicting the melting temperature of alloys containing four or more elements. The reason for this direction of research was the lack of a common understanding of the genesis of the physical properties of substances and, as a consequence, the lack of a universal tool for calculating the melting temperature of alloys. The proposed idea is based on ideas about the natural systematicity of chemical space and the wave properties of matter. Set theory and the theory of addition of random discrete variables are used as mathematical tools. Calculations are carried out for the four-element Wood alloy and the high-entropy five-element AlNbTiVZr alloy. For each of the elements of interest, distribution laws in the «melting temperature» configuration space were compiled, then summed up according to the chemical composition.
Keywords: melting point; element; random discrete quantity; chemical set; wave-particle duality; probability.

M. A. Petrov, D. A. Elesin (Moscow Polytechnic University, Moscow)

Analysis of material flow in the brake disc forging process for different formulations of rheological properties in QForm

The paper studies the flow of technical aluminum AD whose rheological properties are described by three different functions encountered under different forming conditions: hot bulk forging (real and idealized cases) and thixoforming. It is found that the duration of calculations is determined by the presence of narrow channels in which the capillary effect should be observed; this is taken into account by simulating the rise of the material in a capillary tube, deformed under backward extrusion scheme. The description of the material flow and the geometry of the tool have a considerable influence on the choice of process parameters (force-displacement curve and energy of plastic deformation) and the calculation time.
Keywords: rheology of metals and alloys; flow stress; technical aluminum AD; thixoforming; capillary effect; finite-element simulation; QForm.

M. V. Zharov (Moscow Aviation Institute (National Research University), Moscow)

Modeling of metal flow in the manufacture of aircraft panels and shells from aluminum alloys under conditions of isothermal forging and forging in a state of superplasticity

The paper discusses the results of mathematical modeling and real experiments in the production of complex finned products of aviation and military equipment from various aluminum alloys in the implementation of material-saving technologies of isothermal forging and forging in a state of superplasticity. Mathematical modeling is carried out using QForm and DeForm finite element software products. As an object for research, the processes of obtaining complex ribbed aircraft shells from aluminum alloys 01420, AMg3, AMg6, V95, AK6, AK8 were used. The correspondence of the results of mathematical modeling of the processes of obtaining products under isothermal conditions and the process of real stamping of sections of aircraft panels and shells is proved. The temperature and speed parameters of the stamping processes are determined, which make it possible to obtain defect-free products with the maximum material utilization factor.
Keywords: finite element method; modeling; defect; shrinkage depression; clip; oxide scab; deformation rate; temperature and speed modes; isothermal forging; forging in a state of superplasticity; aviation panels; ribbed shells.

Ali Edres Abdulwahab Saleh, A. G. Sattarov, A. V. Sochnev (Kazan National Research Technological University, Kazan)

Laser hardening of the tool surface

Тhe applied method of laser hardening of the tool surface can be applied to a wide range of metal materials in modern industrial applications. In this process, the laser beam focuses on a limited area of the surface of the material that requires hardening. Using high-intensity laser radiation, the surface of the steel is heated to the state of austenite. Due to the rapid conversion of heat in this area, a steep temperature gradient occurs, which leads to instant cooling due to thermal conductivity, which in turn leads to a phase transition from austenite to martensite without the need for external hardening. Various types of lasers, such as CO2, Nd:YAG and diode lasers, are widely used in the industry for the laser quenching process. This review presents the basics of laser quenching with a mention of its advantages over traditional methods of quenching. The results of research published by various scientists based on experiments are presented.
Keywords: laser surface hardening; microhardness; wear resistance; material structure.

A. V. Platonov (Arzamas Polytechnic Institute, branch of Nizhny Novgorod State Technical University named after R. E. Alexeev, Arzamas), A. V. Shchegletov, O. G. Shmelev (Arzamas Machine-Building Plant PJSC, Arzamas); K. A. Shchegletov (Arzamas Polytechnic Institute, branch of Nizhny Novgorod State Technical University named after R. E. Alexeev; Arzamas Scientific and Production Enterprise «Temp-Avia» PJSC, Arzamas); A. S. Blokhina (Arzamas Polytechnic Institute, branch of Nizhny Novgorod State Technical University named after R. E. Alexeev; «APKB» LLC, Arzamas)

Research in the field of maintenance of hinges of non-equal angular velocities of driveshafts of cars (part 1)

Based on the analysis of scientific papers, dissertations, patents and GOST standards, the article reveals the design features of cardan shafts, including their hinges of unequal angular velocities (hereinafter referred to as "hinges"). It was also found that the existing instructions contain some contradictions on the methods of performing maintenance (maintenance) of the products in question. The design of a driveshaft containing an assembly unit in the form of a hinge assembly is proposed, which ensures the performance of maintenance without dismantling the driveshaft from the car.
Keywords: car transmission; design features of cardan shafts; cardan shaft crosspiece; hinge of unequal angular velocities; hinge assembly; the hinge assembly.