OBRABOTKAMETALLOV Vol. 26 No. 4 2024 54 TECHNOLOGY Geometry distortion, edge oxidation, structural changes and cut surface morphology of 100mm thick sheet product made of aluminum, copper and titanium alloys during reverse polarity plasma cutting Artem Grinenko 1, a, Andrey Chumaevsky 2, b, *, Evgeny Sidorov 2, c, Veronika Utyaganova 2, d, Alihan Amirov 2, e, Evgeniy Kolubaev 2, f 1 ITS-Siberia LLC, Krasnoyarsk, 16a Severnoe shosse, 660118, Russian Federation 2 Institute of Strength Physics and Materials Sciences SB RAS, 2/4, pr. Akademicheskii, Tomsk, 634055, Russian Federation a https://orcid.org/0009-0002-9511-1303, giga2011@yandex.ru; b https://orcid.org/0000-0002-1983-4385, tch7av@gmail.com; c https://orcid.org/0009-0009-2665-7514, eas@ispms.ru; d https://orcid.org/0000-0002-2303-8015, veronika_ru@ispms.ru; e https://orcid.org/0000-0002-5143-8235, amir@ispms.tsc.ru; f https://orcid.org/0000-0001-7288-3656, eak@ispms.tsc.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. 2024 vol. 26 no. 4 pp. 41–56 ISSN: 1994-6309 (print) / 2541-819X (online) DOI: 10.17212/1994-6309-2024-26.4-41-56 ART I CLE I NFO Article history: Received: 17 September 2024 Revised: 01 October 2024 Accepted: 10 October 2024 Available online: 15 December 2024 Keywords: Plasma cutting Macrostructure Heat-aff ected zone Metal melting Cutting parameters Reverse polarity current Thick sheet metal Funding The results were obtained in the framework of the Integrated Project “Establishment of production of high-tech equipment for adaptive high-precision plasma heavy cutting of nonferrous metals for the metallurgical, aerospace and transport industries of the Russian Federation” (Agreement No. 075-11-2022012 dated April 06, 2022) implemented by the ISPMS SB RAS at the fi nancial support of the Ministry of Education and Science of the Russian Federation as part of Decree of the Government of the Russian Federation No. 218 dated April 09, 2010. Acknowledgements Research was partially conducted at core facility “Structure, mechanical and physical properties of materials” and center “Nanotech” ISPMS RAS. ABSTRACT The introduction describes the feasibility of using reverse polarity plasma cutting to produce large-sized non-ferrous metal blanks up to 100 mm thick. Data on the use of plasma cutting with direct and reverse polarity currents for thick sheet metal and the main technological problems associated with its implementation are presented. The purpose of the work is to study the organization of the structure and properties of the near-surface zone, changes in the chemical and phase composition when cutting aluminum, copper and titanium alloys. The research methods are optical and scanning electron microscopy, microhardness measurement, X-ray diff raction and energy-dispersive analysis. Plasma cutting was carried out using air as a plasma-forming and shielding gas, simultaneously with water injection into the discharge chamber and the formation of a “water fog” around the plasma column. Results and discussion. It is shown that both the arc stability and the shape of the plasma column are of great importance in reverse polarity plasma cutting of rolled sheets. The distortion of the cutting geometry during normal operation is greatest in the central part, and with insuffi cient heat input it shifts to the lower part and increases signifi cantly. The operation of the plasma torch in air does not lead to signifi cant changes in the composition of the cutting surface of aluminum and copper alloys. A decrease in the magnesium content near the edge is typical for the aluminum alloy in the surface layers. Cutting of the titanium alloy is accompanied by intense oxidation of the surface, especially in areas of diffi cult metal displacement from the cutting cavity. The formation of titanium oxides, mainly rutile Ti2O, sharply increases the microhardness values in the surface layers, which negatively aff ects the machinability of the cutting edge and requires shot blasting to remove the oxide layer. The conclusion describes the main patterns of implementing reverse polarity plasma cutting of sheet metal from aluminum, copper and titanium alloys with a thickness of 100 mm. For citation: Grinenko A.V., Chumaevsky A.V., Sidorov E.A., Utyaganova V.R., Amirov A.I., Kolubaev E.A. Geometry distortion, edge oxidation, structural changes and cut surface morphology of 100mm thick sheet product made of aluminum, copper and titanium alloys during reverse polarity plasma cutting. Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science, 2024, vol. 26, no. 4, pp. 41–56. DOI:10.17212/1994-6309-2024-26.4-41-56. (In Russian). ______ * Corresponding author Chumaevsky Andrey V., D.Sc. (Engineering), Leading researcher, Institute of Strength Physics and Materials Sciences SB RAS, 2/4, pr. Akademicheskii, 634055, Tomsk, Russian Federation Tеl.: +7 (382) 228-68-63, e–mail: tch7av@ispms.ru
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