Abstract
Nd-Fe-B-based alloys as sintered Nd2Fe14B-typed permanent magnets have been studied extensively due to their excellent magnetic properties. In this work, the experimental information on the corresponding phase equilibria of the Nd-Fe-B ternary system in the published literature is reviewed first. The key Nd-Fe-B alloys annealed at 873 and 1073 K were then investigated experimentally to determine the phase equilibria of the system using x-ray diffraction technique and scanning electron microscope (SEM) with energy dispersive spectrometry (EDS). The ternary intermetallic compound, Nd2Fe14B with space group P42/mnm as Nd2Fe14B structure type, NdFe4B4 with space group Pccn as REl.11Fe4B4 structure type and Nd5Fe2B6 with space group R \( \overline{3} \) m as Pr5Co2B6 structure type were confirmed at 873 and 1073 K. The binary intermetallic compound Nd5Fe17 is stable at 873 K, while it was not found at 1073 K. The phase equilibria of the Nd-Fe-B ternary system consists of 14 single-phase regions, 28 two-phase regions and 16 three-phase regions at 873 K, while there are 8 single-phase regions, 14 two-phase regions and 7 three-phase regions at 1073 K except for the B-rich part.
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M. Sagawa, S. Fujimura, N. Togawa, H. Yamamoto, and Y. Matsuura, New Material for Permanent Magnets on a Base of Nd and Fe, J. Appl. Phys., 1984, 55, p 2083-2087
S. Guo, Y.H. Liu, B.C. Chen, C.J. Yan, R.J. Chen, D. Lee, and A. Yan, Effect of Hydriding Degree on the Microstructure and Magnetic Properties of Sintered NdFeB Magnets, J. Appl. Phys., 2012, 111, p 827-831
S. Sugimoto, Current Status and Recent Topics of Rare-Earth Permanent Magnets, J. Phys. Appl. Phys., 2011, 44, p 110-118
N. Poudyal and J.P. Liu, Advances in Nanostructured Permanent Magnets Research, J. Phys. Appl. Phys., 2012, 46, p 43001-43023
N.F. Chaban, Yu.B. Kuz’ma, N.S. Bilonizhko, O.O. Kachmar, and N.V. Petrov, Ternary (Nd, Sm, Gd)-Fe-B Systems, Dopov. Akad. Nauk URSR Ser. A Fit. Mat. Tekh. Nauki., 1979, 10, p 873-876.
K. Loëwe, C. Brombacher, M. Katterb, and O. Gutfleisch, Temperature Dependent Dy Diffusion Processes in Nd-Fe-B Permanent Magnets, Acta Mater., 2015, 83, p 248-255
O. Gutfleisch, M.A. Willard, E. Brück, C.H. Chen, S.G. Sankar, and J.P. Liu, Magnetic Materials and Devices for the 21st Century: Stronger, Lighter, and More Energy Efficient, Adv. Mater., 2011, 23, p 821-842
H. Nakamura, K. Hirota, T. Ohashi, and T. Minowa, Coercivity Distributions in Nd-Fe-B Sintered Magnets Produced by the Grain Boundary Diffusion Process, J. Phys. Appl. Phys., 2011, 44, p 540-545
M. Sagawa, S. Hirosawa, H. Yamamoto, S. Fujimura, and Y. Matsuura, Nd-Fe-B Permanent Magnet Materials, Jpn. J. Appl. Phys., 1987, 26, p 785-800
T.H. Kim, S.R. Lee, S. Namkumg, and T.S. Jang, A Study on the Nd-Rich Phase Evolution in the Nd-Fe-B Sintered Magnet and Its Mechanism During Post-sintering Annealing, J. Alloys Compd., 2012, 537, p 261-268
K. Kobayashi, K. Urushibata, T. Matsushita, S. Sakamoto, and S. Suzuki, Magnetic Properties and Domain Structures in Nd-Fe-B Sintered Magnets with Tb Additive Reacted and Diffused from the Sample Surface, J. Alloys Compd., 2014, 615, p 569-575
C.D. Fuerst, T.W. Capehart, F.E. Pinkerton, and J.F. Herbst, Preparation and Characterization of La2−x Ce x Fe14B Compounds, J. Magn. Magn. Mater., 1995, 139, p 359-363
W.F. Li, H.S. Amin, T. Ohkubo, N. Hase, and K. Hono, Distribution of Dy in High-Coercivity (Nd, Dy)-Fe-B Sintered Magnet, Acta Mater., 2011, 59, p 3061-3069
J.W. Kim, S.H. Kim, S.Y. Song, and Y.D. Kim, Nd-Fe-B Permanent Magnets Fabricated by Low Temperature Sintering Process, J. Alloys Compd., 2013, 551, p 180-184
Z.H. Hu, F.Z. Lian, M.G. Zhu, and W. Li, Effect of Tb on the Intrinsic Coercivity and Impact Toughness of Sintered Nd-Dy-Fe-B Magnets, J. Magn. Magn. Mater., 2008, 320, p 1735-1738
F. Vial, F. Joly, E. Nevalainen, M. Sagawa, K. Hiraga, and K.T. Park, Improvement of Coercivity of Sintered NdFeB Permanent magnets by Heat Treatment, J. Magn. Magn. Mater., 2002, 1329, p 242-245
J. Fidler, T. Schrefl, S. Sasaki, and D. Suess, The Role of Intergranular Regions in Sintered Nd-Fe-B Magnets with (BH)max < 420 kJ m3 (52.5 MGOe), Jpn. Inst. Met., 2000, 14, p S45-S54
L. Liang, M.Y. Wu, L.H. Liu, C. Ma, J. Wang, J.D. Zhang, and L.T. Zhang, Sensitivity of Coercivity and Squareness Factor of a Nd-Fe-B Sintered Magnet on Post-sintering Annealing Temperature, J. Rare Earths, 2015, 33, p 507-513
W.F. Li, Ohkubo, and K. Hono, Effect of Post-sinter Annealing on the Coercivity and Microstructure of Nd-Fe-B Permanent Magnets, Acta Mater., 2009, 57, p 1337-1346
F.G. Chen, T.Q. Zhang, J. Wang, L.T. Zhang, and G.F. Zhou, Investigation of Domain Wall Pinning Effect Induced by Annealing Stress in Sintered Nd-Fe-B Magnet, J. Alloys Compd., 2015, 640, p 371-375
T.B. Massalski, H. Okamoto, P.R. Subramanian, and L. Kacprzak, Binary Alloy Phase Diagrams, ASM International, Materials Park, 1990
W. Zhang, G. Liu, and K. Han, The Fe-Nd (Iron-Neodymium) System, J. Phase Equilib., 1992, 13, p 645-648
A.M. Gabay, A.G. Popov, V.S. Belozerov, and A.S. Yermolenko, The Structure and Magnetic Properties of Rapidly Quenched and Annealed Multi-phase Nanocrystalline Nd9Fe91−x B x , Ribbons, J. Alloys Compd., 1996, 245, p 119-124
F.J.G. Landgraf, G.S. Schneider, V. Villas-Boas, and F.P. Missell, Solidification and Solid State Transformations in Fe-Nd: A Revised Phase Diagram, J. Less Commom Met., 1990, 163, p 209-218
H. Okamoto, Fe-Nd (Iron-Neodymium), J. Phase Equilib., 1997, 18, p 106-106
J.M. Moreau, L. Paccard, J.P. Nozieres, F.P. Missel, G.S. Schneider, and V. Villas-Boas, A New Phase in the Nd-Fe System: Crystal structure of Nd5Fe17, J. Less-Commom Met., 1990, 163, p 245-251
C. Lin, C.X. Liu, Y.X. Sun, Z.X. Liu, D.F. Chen, C. Gou, K. Sun, and J.L. Yang, Neutron Diffraction Study of Nd5Fe17, J. Magn. Magn. Mater., 1998, 186, p 129-134
M.A.V. Ende and I.H. Jung, Critical Thermodynamic Evaluation and Optimization of the Fe-B, Fe-Nd, B-Nd and Nd-Fe-B Systems, J. Alloys Compd., 2013, 548, p 133-154
K.I. Portnoi, M.K. Levinskaya, and V.M. Romashov, Constitution Diagram of the System Iron-Boron, Sov. Powder Metall. Met. Geram., 1969, 8, p 657-659
P.K. Liao, K.E. Spear, and M.E. Schlesinger, The B-Nd (Boron-Neodymium) System, J. Phase Equilib., 1996, 17, p 335-339
H.A. Eick and P.W. Gilles, Precise Lattice Parameters of Selected Rare Earth Tetra-and Hexa-Borides, J. Am. Chem. Soc., 1959, 81, p 5030-5032
J. Roger, V. Babizhetskyy, R. Jardin, J.F. Halet, and R. Guérin, Solid State Phase Equilibria in the Ternary Nd-Si-B System at 1270 K, J. Alloys Compd., 2006, 415, p 73-84
E.K. Storm, Phase Relationship, Vaporization, and Thermodynamic Properties of Neodymium Hexaboride, J. Phys. Chem., 1981, 85, p 1536-1540
K.H.J. Buschow, New Permanent Magent Materials, Mater. Sci. Rep., 1986, 1, p 1-64
K.H.J. Buschow, D.B. de Mooij, and H.M. Van Noort, The Fe-Rich Isothermal Section of Nd-Fe-B at 900 °C, Philips J. Res., 1985, 40, p 227-238
G. Schneider, ETh Heing, G. Petzow, and H.H. Stadelmaier, Phase Relations in the Fe-Nd-B System, Z. Metallkd., 1986, 77, p 755-761
J.F. Herbst, J.J. Croat, and F.E. Pinkerton, Relationships Between Crystal Structure and Magnetic Properties, Phys. Rev. B, 1986, 29, p 4176-4178
N. Zhang and Y. Luo, Phase Diagram of Nd-Fe-B Ternary System, Sci. Sin. Ser. B, 1989, 5, p 329-332
G.C. Che and J.K. Liang, Phase Diagram of Nd-Fe-B Ternary System, Sci. Sin. A, 1986, 29, p 1172-1185
V. Raghavan, The B-Fe-Nd (Boron-Iron-Neodymium) System, Phase Diagrams of Ternary Iron Alloys, Part 6A, Ind. Inst. Metals, Calcutta, 1992, p 374-386.
A. Malfliet, G. Cacciamani, N. Lebrun, and P. Rogl, Boron-Iron-Neodymium. Iron System, Part 1, Springer, Berlin, 2008, p 482-511
K.G. Knoch, B. Reinsch, and G. Peztow, Nd2Fe14B Its Region of Primary Solidification, Z. Metallkd., 1994, 85, p 350-353
F.J.G. Landgraf, F.P. Missell, G. Knoch, B. Grieb, and E.T. Heing, Binary Fe-Nd Metastable Phase in the Solidification of Fe-Nd-B Alloys, J. Appl. Phys., 1991, 70, p 6107-6109
Y. Mastsuura, S. Hirosawa, H. Yamamoto, S. Fujimura, M. Sagawa, and K. Osamura, Phase Diagram of the Nd-Fe-B System, Jpn. J. Appl. Phys., 1985, 24, p 635-637
J.F. Herbst, J.J. Croat, and F.E. Pinkerton, Relationships Between Crystal Structure and Magnetic Properties, Phys. Rev. B, 1986, 29, p 4176-4178
D. Divord and P. Tenaud, Refinement of the Crystal Structure of R1 + εFe4B4 Compounds (R = Nd, Gd), J. Less-Common Met., 1986, 123, p 109-116
D.B. De Mooij and K.H.J. Buschow, Note on the Structure and Composition of the B-rich Ternary Phase in the Nd-Fe-B System, Philips J. Res., 1988, 43, p 70-74
B. Hallemans, P. Wollants, and J.R. Roos, Thermodynamic Assessment of the Fe-Nd-B Phase Diagram, J. Phase Equilib., 1995, 16, p 137-149
V. Raghavan, B-Fe-Nd (Boron-Iron-Neodymium), J. Phase Equilib., 2013, 34, p 124-128
H. Werheit, U. Kuhlmann, M. Laux, and T. Lundstrom, Structural and Electronic Properties of Carbon-Doped ß-Rhombohedral Boron, Phys. Status Solidi (b), 1993, 179, p 489-511
Acknowledgments
This work was supported by National Basic Foundation of China (Grant No. 2014CB643703), Guangxi Natural Science Foundation (Grant Nos. 2014GXNSFBA118235, 2013GXNSFCA019017, 2012GXNSFGA060002) and Guangxi Key Laboratory of Information Materials, Guilin University of Electronic Technology, China (Grant No. 1210908-216-Z). The authors also acknowledge National Natural Science Foundation of China (Grant No. 51461013) for financial support.
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Fu, G., Wang, J., Rong, M.H. et al. Phase Equilibria of the Nd-Fe-B Ternary System. J. Phase Equilib. Diffus. 37, 308–318 (2016). https://doi.org/10.1007/s11669-016-0458-y
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DOI: https://doi.org/10.1007/s11669-016-0458-y