Evaluation of the level of hardening of aluminum alloy chips intended for subsequent pressure treatment

OBRABOTKAMETALLOV Vol. 23 No. 1 2021 TECHNOLOGY Evaluation of the level of hardening of aluminum alloy chips intended for subsequent pressure treatment Yuri Loginov 1, 2, a,* , Nickolay Zagirov 3, b , Evgeniy Ivanov 3, c 1 Ural Federal University named after the fi rst President of Russia B.N. Yeltsin, 19 Mira str., Ekaterinburg, 620002, Russian Federation 2 M.N. Mikheev Institute of Metal Physics of the Ural Branch of the Russian Academy of Sciences, 18 S. Kovalevskaya str., Ekaterinburg, 620137, Russian Federation 3 Siberian Federal University, 79 Svobodny Avenue, Krasnoyarsk, 660041, Russian Federation a https://orcid.org/0000-0002-7222-2521, j.n.loginov@urfu.ru , b https://orcid.org/0000-0003-0144-5063, nzagiroff@mail.ru c https://orcid.org/0000-0002-7585-6140, kafomd_1@mail.ru Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science. 2021 vol. 23 no. 1 pp. 45–55 ISSN: 1994-6309 (print) / 2541-819X (online) DOI: 10.17212/1994-6309-2021-23.1-45-55 Obrabotka metallov - Metal Working and Material Science Journal homepage: http://journals.nstu.ru/obrabotka_metallov ARTICLE INFO Article history : Received: 30 December 2020 Revised: 13 January 2021 Accepted: 06 February 2021 Available online: 15 March 2021 Keywords : Technogenic formations Chip processing Aluminum alloy Finite element method Plastic deformation Funding The work is performed with fi nancial support of the Government of the Russian Federation, Act No. 211, Contract No. 02.A03.21.0006. ABSTRACT Introduction . It is noted that the chip is an undesirable type of metal scrap, because it has a developed surface, which creates conditions for more intense interaction with the surrounding atmosphere. This creates conditions for oxidation and gas saturation, especially at elevated temperatures typical of remelting processes. Therefore, the process of chip utilizing is considered, bypassing the remelting stage. The aim of the work is to establish the level of work hardening of chips during the processing of aluminum alloys and to predict its effect on the subsequent processing process. Research methods : to assess the deformed state, the fi nite element method was applied, implemented in the RAPID-2D software package. The sequence of actions included the creation of the initial shape of the deformation region and the con fi guration of the tool. The mutual displacement of the tool and the deformable material is speci fi ed using the corresponding boundary conditions. The deformable medium is a viscous-plastic material with power-law hardening, the physical and mechanical properties correspond to an aluminum-magnesium alloy. Results and discussion : the solution obtained shows that the degree of shear deformation in the chips can reach a value of more than 2. In this case, a higher level of deformation is localized on the side of the convex part of the chip. The comparison of the solution with those obtained earlier by other authors is carried out and its similarity is shown. In the considered solution, the difference in the degree of work-hardening of the chips along its thickness is 36 %. A variant of the sequence of processing the workpiece fi rst by cold deformation, and then by cutting is considered. The fi eld of application of the results of the work is the development of methods for the processing of technogenic formations. Conclusions . During the cutting process, the plastic deformation of the chips reaches signi fi cant values. In this paper, the difference in the degree of shear deformation in the chip thickness is established, depending on the proximity of the cut layer to the surface of the cutting tool. It is proposed to take this difference into account at the subsequent stages of chip processing. The presence of the marked inhomogeneity of mechanical properties leads to consequences in the form of an inhomogeneous distribution of the temperature of the beginning of recrystallization during subsequent operations of heat treatment or hot deformation treatment. The principle of additivity of the degree of deformation obtained by the metal at the stage of plastic shaping of the workpiece and the shaping of the chip itself is introduced. For citation: Loginov Yu.N., Zagirov N.N., Ivanov E.V. Evaluation of the level of hardening of aluminum alloy chips intended for subsequent pressure treatment. Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science , 2021, vol. 23, no. 1, pp. 45–55. DOI: 10.17212/1994-6309-2021-23.1-45-55. (In Russian). ______ * Corresponding author Loginov Yuri N. , Ph.D. (Engineering), Full Professor Ural Federal University, 19 Mira street, 620002, Ekaterinburg, Russian Federation Tel.: 8 (343) 375-44-37, e-mail: j.n.loginov@urfu.ru Introduction The processes of pressure treatment produce a smaller amount of waste compared to cutting treatment, and the waste itself is less dispersed than the chips, which allows them to be remelted with fewer losses. However, not all processes of giving products the desired shape can be performed by pressure treatment.