OBRABOTKAMETALLOV Vol. 25 No. 2 2023 29 TECHNOLOGY References 1. Zhilyaev A.P., Nurislamova G.V., Kim B.K., Baro M.D., Szpunar J.A., Langdon T.G. Experimental parameters infl uencing grain refi nement and microstructural evolution during high-pressure torsion. Acta Materialia, 2003, vol. 51, iss. 3, pp. 753–765. DOI: 10.1016/S1359-6454(02)00466-4. Analytical model of equal-channel angular pressing of titanium sponge Ivan Berezin 1, 2 a,*, Alexander Zalazinsky 3, b, Denis Kryuchkov 3, c* 1 Ural Federal University named after the fi rst President of Russia B.N. Yeltsin, 19 Mira st., Ekaterinburg, 620002, Russian Federation 2 GUIDE SYSTEMS LLC, 18b Rodonitova str., Ekaterinburg, 620089, Russian Federation 3 Institute of Engineering Science, Ural Branch of the Russian Academy of Science, 34 Komsomolskaya str., Ekaterinburg, 620049, Russian Federation a https://orcid.org/0000-0002-8674-3352, i.m.berezin@urfu.ru, b https://orcid.org/0000-0001-8352-5475, zalaz@list.ru, c https://orcid.org/0000-0001-8585-3544, kru4koff @bk.ru Obrabotka metallov - Metal Working and Material Science Journal homepage: http://journals.nstu.ru/obrabotka_metallov Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science. 2023 vol. 25 no. 2 pp. 17–31 ISSN: 1994-6309 (print) / 2541-819X (online) DOI: 10.17212/1994-6309-2023-25.2-17-31 ART I CLE I NFO Article history: Received: 28 February 2023 Revised: 29 March 2023 Accepted: 28 April 2023 Available online: 15 June 2023 Keywords: Model Equal-channel angular pressing Titanium sponge FEM Funding The work was fi nanced by the State budget. A theme No. 0391-2019-0005 “Development of scientifi c bases of designing of optimum production engineering plastic forming of metal materials with the secured level of a continuity and physicomechanical properties”. Acknowledgements Researches were conducted at core facility of NSTU “Structure, mechanical and physical properties of materials”. ABSTRACT Introduction. The use of equal-channel angular pressing (ECAP) of metal powder makes it possible to obtain practically non-porous blanks with high hardness, with a high level of accumulated deformation and with the formation of an ultra-fi ne-grained structure. A relevant issue for the study of the semi-continuous ECAP process remains a reliable assessment of the energy-power parameters of the process and the prediction of the porosity of compressed materials. This, in turn, is due to the need to develop suffi ciently accurate, reliable and simple mathematical models for practical application. The purpose of the work is to develop an analytical model of the process of equal-channel angular pressing of porous material. Powdered screening of spongy titanium of the TG-100 brand was selected as a model of the material for the study. The object of the study is the process of semi-continuous equal-channel angular pressing of axisymmetric porous briquette of titanium sponge in the channel of the mold. It is assumed that the ECAP uses a punch to create back pressure. For the solution, a process scheme, a statically permissible load scheme on a layer of intense deformation and a kinematically permissible fl ow scheme of a plastically compressible medium in a layer are determined. A system of equations is constructed in accordance with the accepted schemes. The equation power balance is applied. The analytical equation is solved by the method of successive approximations. Finite element simulation of the porous titanium ECAP process was carried out at the angles of intersection of the mold channels at 45°, 50°, 55° and 60°. Results and Discussion. The porosity of the blank is determined at diff erent stages of the ECAP process. A diagram of the change in pressure on the punch using the analytical solution and fi nite element simulation is obtained. It is revealed that the results of the analytical solution are consistent with the data of the fi nite element simulation. The highest stress level occurs in the process of equal-channel angular pressing at α = 45°, however, the distribution of relative density over the cross section is most uniform. The maximum value of the pressure on the working punch decreases with an increase in the angle α. Rational technological parameters of pressing porous blanks should provide the maximum permissible pressure on the deforming tool. From this condition, in each specifi c ECAP process, it is possible to determine the optimal angle value from the analytical solution. For citation: Berezin I.M., Zalazinsky A.G., Kryuchkov D.I. Analytical model of equal-channel angular pressing of titanium sponge. Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science, 2023, vol. 25, no. 2, pp. 17–31. DOI: 10.17212/1994-6309-2023-25.2-17-31. (In Russian). ______ * Corresponding author Kryuchkov Denis I., Ph.D. (Engineering), Researcher Institute of Engineering Science, Ural Branch of the Russian Academy of Science, 34 Komsomolskaya str., 620049, Ekaterinburg, Russian Federation Tel.: 8 (343) 374-50-51, e-mail: kru4koff @bk.ru
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