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ArticleName Study of homogenization effect on the phase composition of Sm2(Fe, Co)17 alloys
DOI 10.17580/nfm.2016.12.09
ArticleAuthor Tarasov V. P., Ignatov A. S.

National University of Science and Technology “MISiS”, Moscow, Russia:

V. P. Tarasov, Head of Department of Non-Ferrous Metals and Gold, Professor, e-mail:
A. S. Ignatov, Assistant, Department of Non-Ferrous Metals and Gold


The aim of this work is elaboration of compositions of nanostructured hard magnetic materials (HMM) on basis of intermetallic compounds of the rare-earth metals (REM) with the iron-group transition metals, which posses the remanent magnetization (Br) no less than 1.20 T and coercive force (Hci) no more than 720 kA/m. The emphasis of this paper has been on research of correlation between parameters of manufacturing process and actual structure of the high-coercive magnetic materials as well as on optimization of the phase composition of high-coercive nanostructured (HMM) based on nitrogen-containing alloys of REM. One of the basic means of increasing Sm2Fe17N3 HMM magnet characteristics is lessening the SmFe3 and SmFe2 submagnetic phases content in magnetic medium, but chiefly the α-Fe presence, which leads to a drastic decrease of coercive force. And at the same time, the sole way to influence the process of phases distribution and formation in an ingot of magnetic material is optimization of the Sm2Fe17 primary alloys melting practice. Optimal phase composition of Sm2(Fe, Co)17N3 high-coercive HMM contains no less than 92% of the Sm2(Fe, Co)17N3 basic magnet phase and no more than 0.5% of -Fe phase. It has been studied a phase co composition by value of the Sm2(Fe0.8Со0.2)17 alloy ingots, obtained by vacuum induction smelting and the following pouring into metal mould. As a result of the research it has been confirmed that phase composition of Sm2Fe17 alloys, obtained by inductive smelting, has great heterogeneity which is mostly determined by the cooling rate. Effect of a high-temperature homogenization on the phase compositions of Sm2(Fe0.8Со0.2)17 alloys has been shown. The optimum temperaturetime mode of homogenization has been determined.

This article was written within the implementation of the Agreement on subsidies No. 14.578.21.0037 of July 22, 2014. (Unique identifier of the Agreement: RFMEFI57814X0037) between the National University of Science and Technology “MISiS” and the Ministry of Education and Science of the Russian Federation within the framework of the implementation of the Federal Target Program “Research and Development in the Priority Directions of the Scientific and Technological Complex of Russia Progress for 2014–2020”, approved by the Decree of the Government of the Russian Federation of November 28, 2013, No. 1096.

keywords Hard magnetic materials, homogenization, permanent magnets, nitrogen-containing REM-Fe compounds, rare-earth metals, phase composition, nanostructured materials, magnetic composite materials

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Full content Study of homogenization effect on the phase composition of Sm2(Fe, Co)17 alloys