OBRABOTKAMETALLOV Vol. 25 No. 4 2023 technology sufficiently high level (-1,600 MPa). Thus, an all-round compression behavior is ensured here, and the presence of high (modulo) values of the mean stress allows to expect an increase in the level of ductility, which should prevent metal fracture. 4. In the first variant, the highest strain degree of the outer bars is observed at its peripheral part on the side bordering the center bar. In this case, the difference in the strain degree over the diameter of the peripheral bars reaches 28 %, while in the central bar it does not exceed 10 %. 5. In the second variant of the channel axes arrangement, the difference in the strain degree over the diameter of all bars is less than 10 %. 6. In both variants of the process, the maximum strain degree can reach a value of 2.6 at the initial stage and 5.0 at the steady stage, with the maximum strain degree achieved at a considerable distance from the front ends of the bars in both variants. Thus, the front ends of the bars may be not sufficiently structured. 7. It is established that when the die is used with the first variant of the channel axes arrangement, the strain level along the bar length is less than when the die channel axes are arranged according to the second variant. The difference reaches 20 % on average. References 1. Biswas S., Dhinwal S.S., Suwas S. Room-temperature equal channel angular extrusion of pure magnesium. Acta Materialia, 2010, vol. 58 (9), pp. 3247–3261. DOI: 10.1016/j.actamat.2010.01.051. 2. Fatemi-Varzaneh S.M., Zarei-Hanzaki A. Accumulative back extrusion (ABE) processing as a novel bulk deformation method. Materials Science and Engineering: A, 2009, vol. 504, pp. 104–106. DOI: 10.1016/j. msea.2008.10.027. 3. Yang Q., Jiang B., He J., Song B., Liu W., Dong H., Pan F.S. Tailoring texture and refining grain of magnesium alloy by differential speed extrusion process. Materials Science and Engineering: A, 2014, vol. 612, pp. 187–191. DOI: 10.1016/j.msea.2014.06.045. 4. Markushev M.V. K voprosu ob effektivnosti nekotorykh metodov intensivnoi plasticheskoi deformatsii, prednaznachennykh dlya polucheniya ob”emnykh nanostrukturnykh materialov [On the methods of severe plastic deformation for bulk nanomaterials processing]. Pis’ma o materialakh = Letters on Materials, 2011, vol. 1 (1), pp. 36‒42. DOI: 10.22226/2410-3535-2011-1-36-42. 5. Minárik P., Král R., Janeček M. Effect of ECAP processing on corrosion resistance of AE21 and AE42 magnesium alloys. Applied Surface Science, 2013, vol. 281, pp. 44‒48. DOI: 10.1016/j.apsusc.2012.12.096. 6. Volkov A.Yu., Antonova O.V., Kamenetskii B.I., Klyukin I.V., Komkova D.A., Antonov B.D. Production, structure, texture, and mechanical properties of severely deformed magnesium. The Physics of Metals and Metallography, 2016, vol. 117, pp. 518‒528. DOI: 10.1134/S0031918X16050161. 7. Naik G.M., Gote G.D., Narendranath S. Microstructural and Hardness evolution of AZ80 alloy after ECAP and post-ECAP processes. Materials Today: Proceedings, 2018, vol. 5, iss. 9 (3), pp. 17763–17768. DOI: 10.1016/j. matpr.2018.06.100. 8. Raab G.I., BotkinA.V., RaabA.G., Valiev R.Z. New schemes of ECAP processes for producing nanostructured bulk metallic materials. AIP Conference Proceedings, 2007, vol. 907, pp. 641–646. DOI: 10.1063/1.2729585. 9. Martynenko N., Lukyanova E., Serebryany V., Prosvirnin D., Terentiev V., Raab G., Dobatkin S., Estrin Y. Effect of equal channel angular pressing on structure, texture, mechanical and in-service properties of a biodegradable magnesium alloy. Materials Letters, 2019, vol. 238, pp. 218‒221. DOI: 10.1016/j.matlet.2018.12.024. 10. Jahadi R., Sedighi M., Jahed H. ECAP effect on the micro-structure and mechanical properties of AM30 magnesium alloy. Materials Science and Engineering: A, 2014, vol. 593, pp. 178‒184. DOI: 10.1016/j. msea.2013.11.042. 11. Ivanov A.M. Ustroistvo dlya odnovremennogo ravnokanal’nogo uglovogo pressovaniya chetyrekh zagotovok [Device for simultaneous equal-channel angular pressing of four blanks]. Patent RF, no. 2475320, 2013. 12. Loginov Yu.N., Burkin S.P. Otsenka neravnomernosti deformatsii i davlenii pri uglovom pressovanii [Evaluation of deformation and pressure irregularity in angle extrusion]. Kuznechno-shtampovochnoe proizvodstvo. Obrabotka materialov davleniem = Forging and stamping production. Material working by pressure, 2001, no. 3, pp. 29–34. 13. Loginov Yu.N., Zamaraeva Yu.V., Komkova D.A. Strains under angular pressing of a strip from a cylindrical billet. Defect and Diffusion Forum, 2021, vol. 410, pp. 80–84. DOI: 10.4028/www.scientific.net/DDF.410.80.
RkJQdWJsaXNoZXIy MTk0ODM1