OBRABOTKAMETALLOV Vol. 28 No. 2 2026 261 MATERIAL SCIENCE References 1. Yeh J.W., Chen S.K., Lin S.J., Gan J.Y., Chin T.S., Shun T.T., Chang S.Y. Nanostructured high-entropy alloys with multiple principal elements: novel alloy design concepts and outcomes. Advanced Engineering Materials, 2004, vol. 6 (5), pp. 299–303. DOI: 10.1002/adem.200300567. 2. Cantor B., Chang I.T.H., Knight P., Vincent A.J.B. Microstructural development in equiatomic multicomponent alloys. Materials Science and Engineering: A, 2004, vol. 375, pp. 213–218. DOI: 10.1016/j.msea.2003.10.257. 3. Zhang Y., Zuo T.T., Tang Z., Gao M.C., Dahmen K.A., Liaw P.K., Lu Z.P. Microstructures and properties of high-entropy alloys. Progress in Materials Science, 2014, vol. 61, pp. 1–93. DOI: 10.1016/j.pmatsci.2013.10.001. Study of the microstructure and properties of high-entropy alloy AlFeCoCrNiNbх fabricated by mechanical alloying and spark plasma sintering Yuanxun Liu 1, b, Zhanna Kovalevskaya 1, а, *, Jingrui Huang 1, c, Margarita Khimich 2, d 1 National Research Tomsk Polytechnic University, 30 Lenin Avenue, Tomsk, 634050, Russian Federation 2 Institute of Strenght Physics and Materials Sciences SB RAS, 2/4 per. Academicheskii, Tomsk, 634055, Russian Federation a https://orcid.org/0009-0002-8501-2643, yuansyun1@tpu.ru; b https://orcid.org/0000-0003-3040-8851, kovalevskaya@tpu.ru; c https://orcid.org/0000-0003-1070-7678, jereehuang@gmail.com; d https://orcid.org/0000-0001-5859-7418, khimich@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. 2026 vol. 28 no. 2 pp. 243–263 ISSN: 1994-6309 (print) / 2541-819X (online) DOI: 10.17212/1994-6309-2026-28.2-243-263 ART I CLE I NFO Article history: Received: 27 January 2026 Revised: 02 February 2026 Accepted: 14 March 2026 Available online: 15 June 2026 Keywords: High-Entropy Alloy AlFeCoCrNiNbx Mechanical alloying Spark plasma sintering Microstructure Microhardness Compression Tests Funding The study was supported by the Russian Science Foundation, Project No. 25-49-00169, https://rscf.ru/project/ 25-49-00169/. ABSTRACT Introduction. Mechanical alloying (MA) combined with spark plasma sintering (SPS) is widely used for the fabrication of high-entropy alloys (HEAs). The combination of MA and SPS eff ectively suppresses grain growth, largely preserving the structure obtained after mechanical activation. This enables the production of HEAs with unique properties. In this study, HEAs of the AlFeCoCrNiNbx system (where x is the molar fraction, x = 0, 0.25, 0.5, and 0.75) were fabricated by MA for 40 hours followed by SPS at 1,000 °C. The purpose of this work is to investigate the eff ect of Nb content on the microstructure and properties of the AlFeCoCrNiNbx high entropy alloy obtained via the combined MA and SPS method. Methods. Both initial powders and sintered samples were studied by X-ray diff raction (XRD), energy-dispersive X-ray spectroscopy (EDS), and scanning electron microscopy (SEM). Microhardness and compressive properties were evaluated, and the resulting fracture surfaces were analyzed. Results and Discussion. During MA, a solid solution with a BCC lattice and a nanoscale substructure was formed in the powder of all AlFeCoCrNiNbx alloys. Alloying with a signifi cant fraction of niobium led to the formation of a small amount of the strengthening Laves phase. Subsequent SPS promoted a phase transformation, resulting in approximately equal volume fractions of a BCC solid solution enriched in Al and Ni and an FCC solid solution enriched in Fe and Cr. Heating facilitated the precipitation of the Laves phase as secondary grains within the BCC solid solution grains. Increasing the Nb content in the alloy led to an increase in the fraction of the Laves phase. Evaluation of the mechanical properties showed that the highest plasticity is characteristic of the AlFeCoCrNi alloy; the highest strength, of the AlFeCoCrNiNb0.25 alloy; the highest hardness, of the AlFeCoCrNiNb0.75 alloy, which is attributed to the specifi c microstructural features and the fraction of the Laves phase in the alloy. For citation: Liu Y., Kovalevskaya Z.G., Huang J., Khimich M.A. Study of the microstructure and properties of high-entropy alloy AlFeCoCrNiNbх fabricated by mechanical alloying and spark plasma sintering. Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science, 2026, vol. 28, no. 2, pp. 243–263. DOI: 10.17212/1994-6309-2026-28.2-243-263. (In Russian). ______ * Corresponding author Kovalevskaya Zhanna G., D.Sc. (Engineering), Professor National Research Tomsk Polytechnic University, 30 Lenin Avenue, 634050, Tomsk, Russian Federation Tel.: +7 906 199-05-77, e-mail: kovalevskaya@tpu.ru
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