OBRABOTKAMETALLOV Vol. 27 No. 4 2025 254 MATERIAL SCIENCE Eff ect of heat treatment on the structure and properties of magnesium alloy MA20 subjected to severe plastic deformation Nikita Luginin 1, 2, a, Anna Eroshenko 1, b, *, Konstantin Prosolov 1, c, Margarita Khimich 1, d, Ivan Glukhov 1, e, Alexander Panfi lov 1, f, Alexey Tolmachev 1, g, Pavel Uvarkin 1, h, Alexander Kashin 1, i, Yurii Sharkeev 1, 2, j 1 Institute of Strength Physics and Materials Sciences SB RAS, 2/4 per. Academicheskii, Tomsk, 634055, Russian Federation 2 National Research Tomsk Polytechnic University, Lenin Ave., 30, Tomsk, 634050, Russian Federation a https://orcid.org/0000-0001-6504-8193, nikishek90@ispms.ru; b https://orcid.org/0000-0001-8812-9287, eroshenko@ispms.ru; c https://orcid.org/0000-0003-2176-8636, konstprosolov@ispms.ru; d https://orcid.org/0000-0001-5859-7418, khimich@ispms.ru; e https://orcid.org/0000-0001-5557-5950, gia@ispms.ru; f https://orcid.org/0000-0001-8648-0743, alexpl@ispms.ru; g https://orcid.org/0000-0003-4669-8478, tolmach@ispms.ru; h https://orcid.org/0000-0003-1169-3765, uvarkin@ispms.ru; i https://orcid.org/0000-0003-1860-3654, kash@ispms.ru; j https://orcid.org/0000-0001-5037-245X, sharkeev@ispms.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. 2025 vol. 27 no. 4 pp. 239–256 ISSN: 1994-6309 (print) / 2541-819X (online) DOI: 10.17212/1994-6309-2025-27.4-239-256 ART I CLE I NFO Article history: Received: 29 July 2025 Revised: 03 September 2025 Accepted: 12 September 2025 Available online: 15 December 2025 Keywords: Magnesium alloys Severe plastic deformation Mechanical properties Heat treatment Phase composition Structure Funding The Russian Science Foundation has fi nancially supported the work, project No. 23-13-00359, available online: https://rscf.ru/project/23-13-00359/. The investigations have been carried out using the equipment of Share Use Centre “Nanotech” of the ISPMS SB RAS and at core facility “Structure, mechanical and physical properties of materials” NSTU. ABSTRACT Introduction. One of the most promising fi elds for the application of magnesium alloys is medicine. Their key advantages are bioresorbability and a low elastic modulus, comparable to that of human cortical bone (up to 30 GPa). Biocompatible Mg-Zn-Zr-Ce (MA20) system alloys are among the most promising for medical applications. Due to their relatively low mechanical properties, the development of severe plastic deformation (SPD) techniques for forming an ultrafi ne-grained (UFG) state in bulk billets of the Mg-Zn-Zr-Ce alloy to achieve optimal functional properties requires further research. Analyzing the conditions for forming a high-strength UFG state necessitates considering various strengthening mechanisms, including well-known ones related to the eff ect of UFG structures. Identifying the deformation and strain hardening mechanisms in magnesium alloys subjected to SPD is also highly relevant. The purpose of this work is to establish the mechanisms of strain hardening and to investigate the infl uence of heat treatment on the structure and properties of the MA20 magnesium alloy after combined SPD. Research methods. The study object was the MA20 alloy in a UFG state (wt. %: Mg – 98.0; Zn – 1.3; Ce – 0.1; Zr – 0.1; O – 0.5). The UFG state was achieved via a combined SPD process involving ABC-pressing followed by multi-pass rolling in grooved rolls. To study the eff ect of annealing on the microstructure and mechanical tensile properties, samples were annealed in air at temperatures of 200, 250, 300, and 500 °C for 24 hours. The microstructure and phase composition of the samples were investigated using optical and transmission electron microscopy. Results and discussion. It was established that applying a combined SPD method (ABC-pressing and multi-pass rolling) to the MA20 alloy results in the formation of an ultrafi ne-grained structure with an average grain size of about 1 μm. This leads to a signifi cant increase in yield strength (σ0.2) to 250 MPa and ultimate tensile strength (σu) to 270 MPa, while simultaneously reducing ductility to 3%. Annealing at 200 °C was found to preserve the UFG state in the MA20 alloy and to lead to a 100% increase in ductility, with an 8% decrease in σ0.2 and a 4% decrease in σu compared to the initial UFG state (non-annealed). Conclusions. It was revealed that the grain boundary (σgrain = = 202 MPa) and dislocation (σdis = 69 MPa) strengthening contributions provide the most signifi cant increase in the strength of the UFG MA20 magnesium alloy. For the magnesium alloy in the UFG and fi ne-grained (FG) states, a critical grain size interval of (1–7) μm was identifi ed, corresponding to a sharp increase in the intensity of change for the calculated contributions of dislocation (dσdis/ dd), grain boundary (dσgrain/ dd), overall strengthening (dσtotal/dd), and dislocation density (dρ/dd). For the coarse-grained (CG) state of the alloy in the grain size range (7–40) μm, these parameters stabilize. For citation: Luginin N.A., Eroshenko A.Yu., Prosolov K.A., Khimich M.A., Glukhov I.A., Panfi lov A.O., Tolmachev A.I., Uvarkin P.V., Kashin A.D., Sharkeev Yu.P. Eff ect of heat treatment on the structure and properties of magnesium alloy MA20 subjected to severe plastic deformation. Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science, 2025, vol. 27, no. 4, pp. 239–256. DOI: 10.17212/1994-6309-2025-27.4-239-256. (In Russian). ______ * Corresponding author Eroshenko Anna Yu., Ph.D. (Engineering), Senior Researcher Institute of Strength Physics and Materials Science SB RAS, 2/4 per. Academicheskii, 634055, Tomsk, Russian Federation Tel.: +7 3822 286 911, e-mail: eroshenko@ispms.ru
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