Abstract
Combined studies of hard magnetic Nd2Fe14B/α-Fe nanocomposites are performed. They were prepared by mechanical alloying of melt-quenched Nd7.4Pr2.0Fe76.6Co4.2Zr3.4B6.4 and Nd5.8Fe80Co4.9Ti1.5Si2.5B5.3 alloys taken in mass proportions of 90/10 and 70/30. It is found that, after mechanical alloying, an amorphous–crystalline structure is formed; it consists of the hard magnetic Nd2Fe14B and soft magnetic (amorphous and α-Fe) phases. Subsequent annealing at ~500°C initiates the decomposition of the amorphous phase and the formation of the nanocrystalline Nd2Fe14B and α-Fe phases. This leads to an increase in the coercivity and the residual magnetization-to-saturation magnetization ratio (σr/σs ≥ 0.5). It is assumed that the magnetic hardening of powders is due to the formation of an exchange-coupled state, which results from the exchange interaction between α-Fe nanocrystals and the Nd2Fe14B phase.
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Original Russian Text © A.G. Savchenko, V.P. Menushenkov, A.Yu. Plastinin, I.V. Shchetinin, A.I. Rafal’skii, I.G. Bordyuzhin, V.A. Ryazantsev, V.N. Verbetskii, 2017, published in Deformatsiya i Razrushenie Materialov, 2017, No. 10, pp. 30–34.
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Savchenko, A.G., Menushenkov, V.P., Plastinin, A.Y. et al. Phase Composition and Magnetic Properties of Nd2Fe14B/α-Fe Nanocomposites Prepared by Mechanical Alloying. Russ. Metall. 2018, 354–358 (2018). https://doi.org/10.1134/S0036029518040134
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DOI: https://doi.org/10.1134/S0036029518040134