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

Statistical aspect of the strength of brittle materials

The article is devoted to the statistical aspect of the strength of brittle materials, which is that the strength of such materials is considered as a random variable, the distribution of defects in the sample obeys statistical laws, and fracture occurs when stress exceeds strength at the weakest point. The calculated equations of the function reflecting the statistical aspect of strength, as well as the criteria for limiting stress states, were considered.
Keywords: statistical aspect of strength; tension; strength of brittle materials; strength criteria.

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

Heat transfer in the rod for the case of linear variation of coating thickness

The article is devoted to the theoretical issues of heat transfer through a rod. The paper considers the case of a linear change in the thickness of the rod coating. At the same time, there are no heat sources in the rod, as well as in the coating layer. The process itself is stationary. The solution to the problem is given using the first-order Bessel equation. This equation arises in mathematical physics problems when solving the Laplace and Helmholtz equations in cylindrical and spherical coordinates.
Keywords: core; heat transfer; coating; variable replacement; differential equation; first-order Bessel equation.

V. V. Krutikova (Leonov University of Technology, Korolev) 

Molybdenum alloys with dispersed hardening

In the framework of this study the methods of hardening of molybdenum alloys, such as strain, solid solution, dispersion and dispersion hardening, are considered. It was found that dispersion strengthening by nitrides of alloying elements is the most effective for achieving high heat resistance. The advantages and limitations of traditional metallurgical techniques and additive technologies for the production of molybdenum alloys have been analyzed. Special attention is paid to the importance of powder metallurgy and hot isostatic pressing for obtaining materials with uniform distribution of dispersed particles and high mechanical characteristics.
Keywords: heat-resistant molybdenum alloys; dispersion hardening; hot isostatic pressing; pellet metallurgy; alloying of molybdenum alloys; plasma centrifugal spraying; nitriding.

M. A. Petrov, D. H. Tran (Moscow Polytechnic University, Moscow)

Determination of the mathematical model of deformation force at microdrawing by means of the design of experiment technique and numerical simulation

The paper reveals the method of formulation of five-factor regression equation with the aim function of maximum deformation force of the microdrawing process for the part like «Cup» made from a copper sheet blank. The equations and plots of interactions between the factors represented by the diameter of the die hole, the radius of the die's inlet edge, the friction coefficient, the blankholder force and the workpiece diameter were taken into consideration. The results are obtained using Minitab software. The effect of each of the above mentioned factors on the maximum deformation force is evaluated.
Keywords: microdrawing; FEM; Abaqus; DoE; Minitab.

A. K. Teben (MSUT «Stankin», Moscow)

The method of assigning cutting speed when working on medium-sized machines to evaluate the effectiveness of using a tool with a wear-resistant coating

The performance of cutters with wear-resistant Zr-ZrN-(ZrNbCrAl) coating is assessed by means of resistance testing. This article provides a method for finding the maximum cutting speed at which a single pass of the turning tool will be provided along the entire length of the workpiece.
Keywords: efficiency; productivity; cutting tool; wear-resistant coating; cutting speed.

A. S. Tsai, A. P. Moroz (Leonov Moscow Region University of Technology (UNITECH), Korolev)

Polytetrafluoroethylene composites: a new vector in tribotechnics

The paper presents general information about polytetrafluoroethylene composites, their tribotechnical characteristics and mechanical properties. Requirements to materials based on polymer composites for tribotechnical application are considered. The features of structure and characteristics of the main types of polytetrafluoroethylene, such as disperse-filled, fibre-reinforced, ultradisperse and others are described. The influence of different fillers on the performance characteristics of tribotechnical composites has been analysed. 
Keywords: polytetrafluoroethylene; polymer composites; tribotechnical materials; mechanical characteristics of tribotechnical materials; fillers for tribotechnical composites.

G. K. Tokabayeva, T. A. Muzdybayeva (Semey Medical University, Semey, Republic of Kazakhstan)

Phase and structural transformations, modification of physico-mechanical properties of metals and alloys

This article examines phase and structural transformations occurring in metals and alloys. The main types of phase transformations, their causes, the influence of structural changes on mechanical properties, as well as the role of temperature and pressure are analyzed. In addition, methods for improving the physico-mechanical properties of metals and alloys are discussed.
Keywords: temperature; pressure; phase transformations; structural changes; mechanical properties.

S. S. Chuikov, V. I. Plekhanov, V. M. Kostiv, A. S. Stavyshenko (Tyumen Industrial University, Tyumen); R. S. Chuikov (Moscow University «Synergy», Moscow)

Improving quality management systems at mechanical engineering enterprises: modern approaches and technologies

This article examines modern approaches to improving product quality management systems at enterprises in the mechanical engineering sector. The introduction of digital technologies, lean manufacturing methods, and the standardization of quality control processes at all stages of the product life cycle are analyzed. Special attention is given to the practical application of quality management tools, using examples from domestic and foreign enterprises. Unique methodologies for optimizing quality control processes, developed by the authors, are described. Conclusions are drawn about the practical significance of integrated quality management systems, and their effectiveness is assessed in the context of production digitalization.
Keywords: quality management; mechanical engineering; lean manufacturing; standardization; digitalization; reliability; integrated systems; digital twin; competitiveness.

S. S. Chuikov, V. I. Plekhanov, V. A. Vasil’kovich, A. S. Stavyshenko (Tyumen Industrial University, Tyumen); R. S. Chuikov (Moscow University «Synergy», Moscow)

The evolution of manufacturing processes in mechanical engineering: from mechanization to full automation

This article explores the transformation of manufacturing processes in mechanical engineering throughout the 20th and 21st centuries. A comprehensive analysis is conducted on the stages of development – from initial mechanization to modern fully automated systems based on cyber-physical platforms, the Industrial Internet of Things (IIoT), predictive analytics systems, and digital twins. Specific examples of the implementation of automation technologies at Russian and international mechanical engineering enterprises are described. Graphic materials illustrating the dynamics of labor productivity growth depending on the level of automation are provided. Mathematical models for optimizing production processes using intelligent systems are presented.
Keywords: mechanization; automation; mechanical engineering; cyber-physical systems; IIoT; digital twin; flexible manufacturing systems; predictive analytics; robotics; labor productivity.

A. V. Konovalov, S. I. Kanyukov, O. Yu. Muizemnek (The Institute of Engineering Science, RAS (Ural Branch), Ekaterinburg)

An approach to the automated design of technological forging processes for forgings of rotation bodies

A unified approach to the automated design of technological forging processes for a wide class of press forgings of rotation bodies is described. A system for classifying forgings by type and a methodology for determining forging types have been developed. A mechanism for automatic development and refinement of the knowledge base on the rules for determining forging types is built. The mechanism has the properties of automatic adjustment to the production conditions of various enterprises.
Keywords: forgings of rotation bodies, types of forgings, methodology for determining types, knowledge base, mechanism of development and refinement of the knowledge base.