OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 24 No. 3 2022 Comparison of approaches based on the Williamson-Hall method for analyzing the structure of an Al0.3CoCrFeNi high-entropy alloy after cold deformation Ivan Ivanov 1, a, *, Daria Safarova 1, b, Zinaida Bataeva 2, c, Ivan Bataev 1, d 1 Novosibirsk State Technical University, 20 Prospekt K. Marksa, Novosibirsk, 630073, Russian Federation 2 Siberian State University of water transport, 33 Schetinkina str., Novosibirsk, 630099, Russian Federation a https://orcid.org/0000-0001-5021-0098, i.ivanov@corp.nstu.ru, b https://orcid.org/0000-0002-2811-8292, safarova10ab@mail.ru, c https://orcid.org/0000-0001-5027-6193, bataevazb@ngs.ru, d https://orcid.org/0000-0003-2871-0269, i.bataev@corp.nstu.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. 2022 vol. 24 no. 3 pp. 90–102 ISSN: 1994-6309 (print) / 2541-819X (online) DOI: 10.17212/1994-6309-2022-24.3-90-102 ART I CLE I NFO Article history: Received: 13 June 2022 Revised: 29 June 2022 Accepted: 05 July 2022 Available online: 15 September 2022 Keywords: High-entropy alloys Al0.3CoCrFeNi, Plastic deformation Cold rolling Synchrotron X-ray diffraction Peak profi le analysis Microhardness Defect structure Funding This study was funded according to Russian Science Foundation research project No.20-73-10215 «In-situ study of the evolution of the dislocation structure of plastically deformed highentropy alloys under high-pressures and temperatures using synchrotron radiation». Research was conducted at core facility “Structure, mechanical and physical properties of materials”. ABSTRACT Introduction. High-entropy alloys (HEAs) belong to a new and promising class of materials that are attracting the attention of both scientists and engineers from all over the world. Among all alloys of the AlxCoCrFeNi system, HEAs with x ≤ 0.3 attract special attention. Materials with this composition are characterized by the presence of only one phase with a face-centered cubic lattice (FCC). Such alloys have high ductility, excellent corrosion resistance and phase stability at high temperatures. The purpose of this work is to compare several methods of profi le analysis on the example of plastically deformed ingots of a high-entropy Al0.3CoCrFeNi alloy. The methods of investigation. Using several methods of profi le analysis of X-ray diffraction patterns, the structures of the cold-worked high-entropy alloy Al0.3CoCrFeNi are studied. In addition to the classical Williamson-Hall method, the analysis was carried out using a modifi ed one, as well as a method that takes into account the anisotropy of the elastic properties of the crystal lattice. Research material. Ingots of the high-entropy Al0.3CoCrFeNi alloy deformed by cold rolling with a maximum reduction ratio of 80% were used as the object of the study. Samples were cut from the obtained blanks, which were studied by the method of synchrotron radiation diffraction according to the “transmission” scheme along two (longitudinal (RD) and transverse (TD)) directions of rolled products. Results and discussion. It is shown that the use of the classical Williamson-Hall method leads to a signifi cant error in the approximation of experimental results. The modifi ed Williamson-Hall method has the smallest approximation error and can be recommended for studying the Al0.3CoCrFeNi alloy. An analysis of deformed samples using this method made it possible to reveal several features of the formation of defects in the crystalline structure, which are in good agreement with the classical concepts of the mechanisms of plastic deformation. First, an increase in the degree of deformation of the high-entropy Al0.3CoCrFeNi alloy leads to an almost uniform increase in the number of twins and stacking faults. Secondly, with an increase in the degree of reduction, there is a decrease in the fraction of edge dislocations and an increase in the fraction of screw dislocations in the material. The results obtained correlate well with the results of microhardness measurements. For citation: Ivanov I.V., Safarova D.E., Bataeva Z.B., Bataev I.A. Comparison of approaches based on the Williamson–Hall method for analyzing the structure of an Al0.3CoCrFeNi high-entropy alloy after cold deformation. Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science, 2022, vol. 24, no. 3, pp. 90–102. DOI: 10.17212/1994-6309-2022-24.3-90-102. (In Russian). ______ * Corresponding author Ivanov Ivan V., Ph.D. (Engineering) Novosibirsk State Technical University, 20 Prospekt K. Marksa, 630073, Novosibirsk, Russian Federation Tel.: 8 (383) 346-11-71, e-mail: i.ivanov@corp.nstu.ru
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