KSHP. OMD №6-2026

A. L. Vorontsov, D. A. Lebedeva (Bauman Moscow State Technical University, Moscow)

Investigation of backward-and-forward extrusion of tumblers with a co-bottom part.
Part 30. Experimental verification of theoretical formulas for backward extrusion

This paper examines the cold backward extrusion of tumblers with a co-bottom part made of a hardening material. Methods for performing specific calculations of the deforming force for various geometric parameters of free and constrained extrusion are demonstrated in detail. The high accuracy of the derived calculation formulas is demonstrated through comparison with experimental data obtained during the extrusion of AD1 aluminum alloy.
Keywords: die forging; metal cup with a conical bottom; combined extrusion; stress; deformation.

K. A. Isaeva (BMSTU, Moscow)

Accounting for contact stiffness of the joint in the design of screw press threaded connections

The analysis of the assumption made in the calculation of threaded connections operating under variable loading is performed. It is shown that neglecting the contact compliance of the joint (typical for the classical approach) is acceptable only for assessing static strength. When determining fatigue resistance, it is necessary to take into account the deformation of microroughnesses in accordance with the model. A numerical calculation for a screw press is presented, demonstrating a 2,5-fold discrepancy in stress amplitudes between the simplified and refined methods. Practical design recommendations are given.
Keywords: contact stiffness; external load factor; fatigue resistance; joint compliance; screw press; surface roughness; threaded connection.

A. V. Razinkin (JSC «Kamensk-Uralsky Metallurgical Works», Kamensk-Uralsky)

Determination of the causes of the opening of the ends of the roll in the process of hot sheet metal rolling of aluminum alloy

As part of the work, an attempt was made to develop a hypothesis and a theoretical model of the reason for the opening of the front end of the roll during sheet metal rolling. It is assumed that the reason for the latter is the occurrence of vertical stresses at the front end of the roll during rolling, stretching this zone in the vertical direction relative to the midline of the rolled workpiece. The ratio of the length of the deformation focus to its average height, which is dangerous from the position of opening the front end of the roll, is determined – the range is 0,4–1. Modeling of the aluminum sheet rolling process confirmed the hypotheses presented in the theoretical part.
Keywords: rolling; aluminum alloys; strain effective; tensile vertical stresses; simulation; DEFORM.

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

A method of probabilistic approximation in long-term strength problems

The article is devoted to the method of probabilistic approximation in problems of long-term strength of materials. The method of probabilistic approximation is a method based on direct experimental data from the time before the destruction and the simplest probabilistic methods. The considered method is used in the industry for approximate description of distributions of random variables, modeling of technological processes, risk assessment and improvement of management quality. It allows you to work with uncertainty, analyze complex systems, and make informed decisions based on approximate models.
Keywords: strength; probabilistic approximation method; stress; model.

F. S. Sabirov, L. Ya. Gilovoy, E. D. Serdyukov (MSUT «STANKIN», Moscow)

The influence of machine dynamics on accuracy in laser cutting

The article examines the main factors determining workpiece processing speed: laser source power, drive type, and rigidity of the supporting system. A comparative analysis of technical specifications of laser machines from leading global manufacturers has been performed. The traditional layout of a CNC laser machine is described. Its key elements are examined in detail: laser resonator, beam delivery optical system, coordinate table, feed drives, and control system. Principles for component selection aimed at increasing equipment productivity while maintaining the required machining accuracy are formulated. Special attention is paid to the analysis of errors occurring during high-speed cutting. It is shown that the greatest deviations from the specified trajectory are observed in zones where the direction of movement along coordinate axes changes, which is caused by drive inertia and elastic deformations of machine elements. The Optimum Tube laser machine is selected as the research object, on which a series of experiments were conducted to evaluate cutting quality. Processing modes are selected considering the physical and mechanical properties of the material and dimensional characteristics of the workpiece. The criterion for mode selection is cut quality without defects such as burrs and melted edges. A vibroacoustic method is applied to evaluate the dynamic properties of the machine's elastic system. Vibration recording is performed during processing while accelerating to various cutting speeds, which allowed identifying zones of unstable equipment operation. A correlation between processing speed and trajectory is established. When certain threshold speed values are exceeded, a sharp increase in part contour deviations from the nominal is observed.
Keywords: laser cutting; laser cutting machine; CNC; machining accuracy; cutting error; feed rate; vibroacoustic analysis; feed drives; tube cutting; dynamic characteristics.

D. N. Galushkin, Yu. G. Asсaturov (ISOiP (branch) of DonSTU in Shakhty, Shakhty); A. V. Rementsov (IT (branch) of DonSTU in Volgodonsk, Volgodonsk)

Improving the efficiency of the drilling process of corrosion-resistant chromium-nickel steels based on electrochemical methods

The article examines the mechanisms of increasing the efficiency of the drilling process of corrosion-resistant steel 1X18N9T by electrochemical polarization of the cutting zone in the medium of technological electrolytes. The main attention is paid to the correlation between the anionic composition of lubricating and cooling technological means (OTS) and the wear rate of cutting tools made of high-speed steel P6M5. Based on the analysis of polarization curves and the morphology of chip formation, it is proved that the use of sulfate media with the addition of the composition «Aquol-6» ensures the electrochemical stability of the tool while selectively softening the processed material. 
Keywords: 1X18H9T steel; electrochemical treatment; tool wear; Rebinder effect; selective dissolution.

A. O. Sapronov (MSUT « Stankin », Moscow)

Finding the best conditions for surface alloying of powder blanks

The process of surface alloying of powder blanks made of iron powder PZHV2.160.28 during subsequent cold extrusion is studied. Before deformation, the blanks are coated with a paste based on graphite or soot with zinc stearate. Using methods of mathematical experimental design and computer simulation in the DEFORM software package, the influence of the initial blank density, coating thickness and composition, as well as the matrix heating temperature on the extrusion force was investigated. An adequate mathematical model describing the dependence of the extrusion force on the factors under study is obtained. It is found that the blank density and the matrix heating temperature have a statistically significant effect on the process force. Using the steepest ascent method on the response surface, the optimal conditions
Keywords: powder metallurgy; surface alloying; cold extrusion; iron powder; experiment design; mathematical model; extrusion force; DEFORM.

V. V. Malkov (JSC «Giredmet»; STU-MADI, Moscow); L. G. Petrova (STU-MADI, Moscow)

Zirconium powder metallurgy: technology evolution and applications

The article provides an overview of the evolution of zirconium powder metallurgy from early laboratory methods to modern high-tech processes. Key historical stages are examined: the Kroll process, iodide refining, the development of metallothermic (sodium- and calcium- reduction) schemes, and hydrogenation-dehydrogenation (HDH) technology. Special attention is paid to the contribution of Russian research and production centers (Giredmet, Chepetsky Mechanical Plant) in creating a closed-loop zirconium production cycle for the nuclear industry. Modern methods for producing zirconium and its alloy powders, including additive technologies are analyzed. It is shown that the development of additive manufacturing imposes new requirements on powders. Key application areas (nuclear energy, chemical engineering, medical technology) and corresponding requirements for powder material properties are identified. The conclusion is made about the industry's transition to integrated technological chains, including waste recycling and powder adaptation for specific forming processes.
Keywords: zirconium; powder metallurgy; hydride-dehydride technology (HDH); metallothermy; sodium reduction; calcium reduction; additive technologies; plasma spheroidization; nuclear engineering.