OBRABOTKAMETALLOV Vol. 25 No. 3 2023 134 MATERIAL SCIENCE Synthesis of Ti–Fe intermetallic compounds from elemental powders mixtures Gennady Pribytkov a, *, Anton Baranovskiy b, Victoria Korzhova c, Irina Firsina d, Vladimir Krivopalov e Institute of Strength Physics and Materials Science of Siberian Branch Russian Academy of Sciences, 2/4 pr. Akademicheskii, Tomsk, 634055, Russian Federation a https://orcid.org/0000-0002-8267-971X, gapribyt@mail.ru, b https://orcid.org/0000-0001-8800-4716, nigalisha@gmail.com, c https://orcid.org/0000-0003-0835-9264, vicvic5@mail.ru, d https://orcid.org/0000-0003-2253-0582, iris1983@yandex.ru, e https://orcid.org/0009-0003-3224-1749, krivopalov@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. 2023 vol. 25 no. 3 pp. 126–136 ISSN: 1994-6309 (print) / 2541-819X (online) DOI: 10.17212/1994-6309-2023-25.3-126-136 ART I CLE I NFO Article history: Received: 10 May 2023 Revised: 23 May 2023 Accepted: 21 June 2023 Available online: 15 September 2023 Keywords: Powder mixture Mechanical activation of synthesis Thermal explosion Titanium-Iron intermetallic compounds Phase composition Enthalpy of compounds formation Funding The work was supported by the Russian Science Foundation (project number 23-29-00106): “In situ synthesis of metal matrix composites with submicron carbide strengthening phase”. Acknowledgements Research was partially conducted at core facility “Structure, mechanical and physical properties of materials”. ABSTRACT Introduction. Intermetallic compounds Fe2Ti and FeTi are of practical application as hydrogen accumulators (FeTi) or as magnetic materials (Fe2Ti). Due to the peculiarities of the double equilibrium diagram, the production of these intermetallic compounds by casting is diffi cult. Therefore, powder metallurgy methods are widely used combined with preliminary mechanical activation of the powder mixtures. The aim of the work is to investigate the possibility of obtaining single-phase compounds from powder mixtures of titanium and iron of target compositions. Research methods. Mechanically activated powder mixtures, products of combustion and subsequent annealing were studied by X-ray phase analysis, optical metallography, and scanning electron microscopy using elemental composition determination by energy-dispersive X-ray spectroscopy. Research methodology. Powder mixtures were mechanically activated for 20 minutes in an Activator 2S planetary ball mill with an intensity of 40 g and a ball/mixture ratio of 20. The mechanically activated mixtures were heated in a sealed reactor in argon media at an average rate of 85 C°/min. Results and discussion. At a temperature of about 500 °C, thermographs of thermocouples placed in a mechanically activated mixture showed a sharp rise (thermal explosion), indicating an exothermic reaction in the mixture. The rise for the 2Fe + Ti composition turned out to be more pronounced than that for the Fe + Ti composition. X-ray diff raction analysis showed that the main reaction product is the Fe2Ti compound for both mixtures. The predominant formation of Fe2Ti is explained by the greater negative enthalpy of Fe2Ti formation of compared to FeTi (−87.45 and −40.58 kcal/mol, respectively). Conclusion. High-temperature annealing of thermal explosion products did not make it possible to obtain single-phase target products. The content of secondary phases and unreacted reagents changed little after annealing. Based on the obtained results, it was concluded that the thermodynamic factor (the enthalpy of formation of the intermetallic compound) is the main one that determines the phase composition of the synthesis products in powder mixtures of titanium and iron. For citation: Pribytkov G.A., Baranovskiy A.V., Korzhova V.V., Firsina I.A., Krivopalov V.P. Synthesis of Ti–Fe intermetallic compounds from elemental powders mixtures. Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science, 2023, vol. 25, no. 3, pp. 126–136. DOI: 10.17212/1994-6309-2023-25.3-126-136. (In Russian). ______ * Corresponding author Pribytkov Gennady A., Ph.D. (Engineering), Associate Professor, General Researcher Institute of Strength Physics and Materials Science of Siberian Branch Russian Academy of Sciences, 2/4 pr. Akademicheskii, 634055, Tomsk, Russian Federation Tel.: +7 (913) 860-04-49, e-mail: gapribyt@mail.ru References 1. Sandrock G. A panoramic overview of hydrogen storage alloys from a gas reaction point of view. Journal of Alloys and Compounds, 1999, vol. 293–295, pp. 877–888. DOI: 10.1016/S0925-8388(99)00384-9.
RkJQdWJsaXNoZXIy MTk0ODM1