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

Investigation of backward-and-forward extrusion of tumblers with a co-bottom part.

Part 25. Experimental verification of theoretical formulas during traditional free spinning process with hardening (beginning)

The cold free traditional free spinning process of tumblers with a co-bottom part from a hardening material is considered. The methods of performing specific calculations of the deforming force for various geometric parameters of extrusion, both for free and constrained spinning processes, are demonstrated in detail. A comparison with experimental data obtained during the spinning of aluminum alloy AD1 and brass L63 shows the high accuracy of the derived calculation formulas.
Keywords: die forging; tumblers with the co-bottom part; backward-and-forward extrusion; stress; deformation.

V. I. Tregubov, A. A. Pasynkov, M. V. Larina (Tula State University, Tula)

Shaping on the inner surfaces of conical body blanks

Light high-strength alloys are used in the industrial production of hollow bodies for the needs of aircraft construction. The manufacture of such parts is mainly associated with significant losses of the blank material. Therefore, the use of slow hot relief forming technology on the inner surface of a hollow conical semi-finished product is more advantageous in terms of reducing metal losses. The article presents CAE modeling of relief formation on conical pipes made of titanium alloy VT6. The influence of high-speed forming conditions and deformation degrees on pressure and stress intensities is revealed. A regression equation is obtained to estimate the process forces. A stamp diagram is presented.
Keywords: forming; conical shells; internal relief; pressure; force; stress.

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

Simulation of thermal stresses of a cylinder with variable volumetric heat release

The work is devoted to the issues of thermal stress. It considers the problem of modeling the thermal stresses of a cylinder with variable volumetric heat release under a boundary condition of the first kind. This takes into account the coordinate dependence of heat release. The solution was obtained using differentiation methods. The result obtained can be useful for determining the thermally stressed state of bodies. This opens up the possibility of reducing temperature stresses in cylindrical parts with a coordinate dependence of volumetric heat generation.
Keywords: cylinder; volumetric heat dissipation; Eri function; temperature stresses.

A. N. Savkin, A. A. Sedov, K. A. Badikov, D. Yu. Abalkhan, A. I. Lebedev (Volgograd State Technical University, Volgograd)

Fractographic features of titanium alloy fracture under various external disturbances

The kinetics of fatigue crack growth in various titanium alloys VT6 (α+β structure) and PT-3V (pseudo-α structure) under external cyclic loading with various types of cyclic disturbances is studied. Experimental results of cyclic tests with the sequences «overload-underload», «underload-overload» on compact C(T) samples are shown. It is noted that the kinetics of crack growth largely depends on the type of sequences of amplitudes of variable loading. Analysis of acceleration and deceleration of crack growth depending on the properties of materials and the nature of the variable external effect is carried out based on the study of fractographic features of crack development. The mechanisms of such crack behavior are discussed.
Keywords: fatigue crack growth kinetics; loading history; acceleration and deceleration of crack growth; titanium alloys; fractography.

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

Investigation of the process of extrusion of high-density cylindrical billets from powder by the method of full factor experiment

The paper presents the process of extrusion of cylindrical billets, with the construction of a mathematical model by multifactor experiment. This method allows to save resources significantly. It also provides the possibility of including factors such as tool motion, workpiece material, and friction conditions. The paper uses the software package Deform 2d, which is a tool to implement and apply this method to the study of extrusion of workpieces.
Keywords: extrusion of «cup» type parts; high-density powder PZh4M3; aluminum alloy AB; friction force.

I. D. Mikheev, A. I. Nazmiev (KNRTU-KAI, Kazan)

Investigation of the process of mutual diffusion of a silicon substrate and an aluminum conductor

The relevance of the application of diffusion welding is considered and an overview of experimental and theoretical work on diffusion welding of process metals with silicon is performed. Experiments have been carried out to create a diffusion welded joint of an aluminum sample and a silicon plate without cleaning the samples and without creating a vacuum environment. The implementation of such a technology can greatly simplify the use of diffusion welding in production conditions.
Keywords: diffusion; diffusion zone; diffusion connection; mutual diffusion; contact zone; activation zone; physical contact; diffusion welding; penetration depth; transition layer.

Yu. S. Abramenko, E. A. Kursevich (RFNC-VNIITF, Snezhinsk)

Application of the main manufacturability coefficients when using additive technologies

The article considers the possibility of assessing the manufacturability of the design of products using additive technologies (AT) using the main indicators of manufacturability: labor, material, and energy intensity. The features of their application and the necessary adaptation for determining the manufacturability of products in the manufacture of parts by additive technologies, taking into account the features of AT, are considered. The issue of the technological cost of manufacturing products using additive manufacturing, taking into account the specifics of AT, is raised. The results of a comparative analysis of the technological cost of a set of parts manufactured by mechanical processing and additive technology are presented. Conclusions are made about the need for a confirmable criterion for the manufacturability of a product for manufacturing by the AT method, taking into account the volume and complexity of product refinement, since unreasonable loading of such high-tech equipment leads to economic losses in the production of products, and therefore reduces the competitiveness of the enterprise.
Keywords: manufacturability of the product design; manufacturability coefficients; additive technologies.